Eye blink detection with OpenCV, Python, and dlib

In last week’s blog post, I demonstrated how to perform facial landmark detection in real-time in video streams.

Today, we are going to build upon this knowledge and develop a computer vision application that is capable of detecting and counting blinks in video streams using facial landmarks and OpenCV.

To build our blink detector, we’ll be computing a metric called the eye aspect ratio (EAR), introduced by Soukupová and Čech in their 2016 paper, Real-Time Eye Blink Detection Using Facial Landmarks.

Unlike traditional image processing methods for computing blinks which typically involve some combination of:

  1. Eye localization.
  2. Thresholding to find the whites of the eyes.
  3. Determining if the “white” region of the eyes disappears for a period of time (indicating a blink).

The eye aspect ratio is instead a much more elegant solution that involves a very simple calculation based on the ratio of distances between facial landmarks of the eyes.

This method for eye blink detection is fast, efficient, and easy to implement.

To learn more about building a computer vision system to detect blinks in video streams using OpenCV, Python, and dlib, just keep reading.

Looking for the source code to this post?
Jump right to the downloads section.

Eye blink detection with OpenCV, Python, and dlib

Our blink detection blog post is divided into four parts.

In the first part we’ll discuss the eye aspect ratio and how it can be used to determine if a person is blinking or not in a given video frame.

From there, we’ll write Python, OpenCV, and dlib code to (1) perform facial landmark detection and (2) detect blinks in video streams.

Based on this implementation we’ll apply our method to detecting blinks in example webcam streams along with video files.

Finally, I’ll wrap up today’s blog post by discussing methods to improve our blink detector.

Understanding the “eye aspect ratio” (EAR)

As we learned from our previous tutorial, we can apply facial landmark detection to localize important regions of the face, including eyes, eyebrows, nose, ears, and mouth:

Figure 1: Detecting facial landmarks in an video stream in real-time.

This also implies that we can extract specific facial structures by knowing the indexes of the particular face parts:

Figure 2: Applying facial landmarks to localize various regions of the face, including eyes, eyebrows, nose, mouth, and jawline.

Figure 2: Applying facial landmarks to localize various regions of the face, including eyes, eyebrows, nose, mouth, and jawline.

In terms of blink detection, we are only interested in two sets of facial structures — the eyes.

Each eye is represented by 6 (x, y)-coordinates, starting at the left-corner of the eye (as if you were looking at the person), and then working clockwise around the remainder of the region:

Figure 3: The 6 facial landmarks associated with the eye.

Based on this image, we should take away on key point:

There is a relation between the width and the height of these coordinates.

Based on the work by Soukupová and Čech in their 2016 paper, Real-Time Eye Blink Detection using Facial Landmarks, we can then derive an equation that reflects this relation called the eye aspect ratio (EAR):

Figure 4: The eye aspect ratio equation.

Where p1, …, p6 are 2D facial landmark locations.

The numerator of this equation computes the distance between the vertical eye landmarks while the denominator computes the distance between horizontal eye landmarks, weighting the denominator appropriately since there is only one set of horizontal points but two sets of vertical points.

Why is this equation so interesting?

Well, as we’ll find out, the eye aspect ratio is approximately constant while the eye is open, but will rapidly fall to zero when a blink is taking place.

Using this simple equation, we can avoid image processing techniques and simply rely on the ratio of eye landmark distances to determine if a person is blinking.

To make this more clear, consider the following figure from Soukupová and Čech:

Figure 5: Top-left: A visualization of eye landmarks when then the eye is open. Top-right: Eye landmarks when the eye is closed. Bottom: Plotting the eye aspect ratio over time. The dip in the eye aspect ratio indicates a blink (Figure 1 of Soukupová and Čech).

On the top-left we have an eye that is fully open — the eye aspect ratio here would be large(r) and relatively constant over time.

However, once the person blinks (top-right) the eye aspect ratio decreases dramatically, approaching zero.

The bottom figure plots a graph of the eye aspect ratio over time for a video clip. As we can see, the eye aspect ratio is constant, then rapidly drops close to zero, then increases again, indicating a single blink has taken place.

In our next section, we’ll learn how to implement the eye aspect ratio for blink detection using facial landmarks, OpenCV, Python, and dlib.

Detecting blinks with facial landmarks and OpenCV

To get started, open up a new file and name it detect_blinks.py . From there, insert the following code:

To access either our video file on disk ( FileVideoStream ) or built-in webcam/USB camera/Raspberry Pi camera module ( VideoStream ), we’ll need to use my imutils library, a set of convenience functions to make working with OpenCV easier.

If you do not have imutils  installed on your system (or if you’re using an older version), make sure you install/upgrade using the following command:

Note: If you are using Python virtual environments (as all of my OpenCV install tutorials do), make sure you use the workon  command to access your virtual environment first and then install/upgrade imutils .

Otherwise, most of our imports are fairly standard — the exception is dlib, which contains our implementation of facial landmark detection.

If you haven’t installed dlib on your system, please follow my dlib install tutorial to configure your machine.

Next, we’ll define our eye_aspect_ratio  function:

This function accepts a single required parameter, the (x, y)-coordinates of the facial landmarks for a given eye .

Lines 16 and 17 compute the distance between the two sets of vertical eye landmarks while Line 21 computes the distance between horizontal eye landmarks.

Finally, Line 24 combines both the numerator and denominator to arrive at the final eye aspect ratio, as described in Figure 4 above.

Line 27 then returns the eye aspect ratio to the calling function.

Let’s go ahead and parse our command line arguments:

Our detect_blinks.py  script requires a single command line argument, followed by a second optional one:

  • --shape-predictor : This is the path to dlib’s pre-trained facial landmark detector. You can download the detector along with the source code + example videos to this tutorial using the “Downloads” section of the bottom of this blog post.
  • --video : This optional switch controls the path to an input video file residing on disk. If you instead want to work with a live video stream, simply omit this switch when executing the script.

We now need to set two important constants that you may need to tune for your own implementation, along with initialize two other important variables, so be sure to pay attention to this explantation:

When determining if a blink is taking place in a video stream, we need to calculate the eye aspect ratio.

If the eye aspect ratio falls below a certain threshold and then rises above the threshold, then we’ll register a “blink” — the EYE_AR_THRESH  is this threshold value. We default it to a value of 0.3  as this is what has worked best for my applications, but you may need to tune it for your own application.

We then have an important constant, EYE_AR_CONSEC_FRAME  — this value is set to 3  to indicate that three successive frames with an eye aspect ratio less than EYE_AR_THRESH  must happen in order for a blink to be registered.

Again, depending on the frame processing throughput rate of your pipeline, you may need to raise or lower this number for your own implementation.

Lines 44 and 45 initialize two counters. COUNTER  is the total number of successive frames that have an eye aspect ratio less than EYE_AR_THRESH  while TOTAL  is the total number of blinks that have taken place while the script has been running.

Now that our imports, command line arguments, and constants have been taken care of, we can initialize dlib’s face detector and facial landmark detector:

The dlib library uses a pre-trained face detector which is based on a modification to the Histogram of Oriented Gradients + Linear SVM method for object detection.

We then initialize the actual facial landmark predictor on Line 51.

You can learn more about dlib’s facial landmark detector (i.e., how it works, what dataset it was trained on, etc., in this blog post).

The facial landmarks produced by dlib follow an indexable list, as I describe in this tutorial:

Figure 6: The full set of facial landmarks that can be detected via dlib (higher resolution).

We can therefore determine the starting and ending array slice index values for extracting (x, y)-coordinates for both the left and right eye below:

Using these indexes we’ll be able to extract eye regions effortlessly.

Next, we need to decide if we are working with a file-based video stream or a live USB/webcam/Raspberry Pi camera video stream:

If you’re using a file video stream, then leave the code as is.

Otherwise, if you want to use a built-in webcam or USB camera, uncomment Line 62.

For a Raspberry Pi camera module, uncomment Line 63.

If you have uncommented either Line 62 or Line 63, then uncomment Line 64 as well to indicate that you are not reading a video file from disk.

Finally, we have reached the main loop of our script:

On Line 68 we start looping over frames from our video stream.

If we are accessing a video file stream and there are no more frames left in the video, we break from the loop (Lines 71 and 72).

Line 77 reads the next frame from our video stream, followed by resizing it and converting it to grayscale (Lines 78 and 79).

We then detect faces in the grayscale frame on Line 82 via dlib’s built-in face detector.

We now need to loop over each of the faces in the frame and then apply facial landmark detection to each of them:

Line 89 determines the facial landmarks for the face region, while Line 90 converts these (x, y)-coordinates to a NumPy array.

Using our array slicing techniques from earlier in this script, we can extract the (x, y)-coordinates for both the left and right eye, respectively (Lines 94 and 95).

From there, we compute the eye aspect ratio for each eye on Lines 96 and 97.

Following the suggestion of Soukupová and Čech, we average the two eye aspect ratios together to obtain a better blink estimate (making the assumption that a person blinks both eyes at the same time, of course).

Our next code block simply handles visualizing the facial landmarks for the eye regions themselves:

You can read more about extracting and visualizing individual facial landmark regions in this post.

At this point we have computed our (averaged) eye aspect ratio, but we haven’t actually determined if a blink has taken place — this is taken care of in the next section:

Line 111 makes a check to see if the eye aspect ratio is below our blink threshold — if it is, we increment the number of consecutive frames that indicate a blink is taking place (Line 112).

Otherwise, Line 116 handles the case where the eye aspect ratio is not below the blink threshold.

In this case, we make another check on Line 119 to see if a sufficient number of consecutive frames contained an eye blink ratio below our pre-defined threshold.

If the check passes, we increment the TOTAL  number of blinks (Line 120).

We then reset the number of consecutive blinks COUNTER  (Line 123).

Our final code block simply handles drawing the number of blinks on our output frame, as well as displaying the current eye aspect ratio:

To see our eye blink detector in action, proceed to the next section.

Blink detection results

Before executing any of these examples, be sure to use the “Downloads” section of this guide to download the source code + example videos + pre-trained dlib facial landmark predictor. From there, you can unpack the archive and start playing with the code.

Over this past weekend I was traveling out to Las Vegas for a conference. While I was waiting for my plane to board, I sat at the gate and put together the code for this blog post — this involved recording a simple video of myself that I could use to evaluate the blink detection software.

To apply our blink detector to the example video, just execute the following command:

And as you’ll see, we can successfully count the number of blinks in the video using OpenCV and facial landmarks:

Later, at my hotel, I recorded a live stream of the blink detector in action and turned it into a screencast.

To access my built-in webcam I executed the following command (taking care to uncomment the correct VideoStream  class, as detailed above):

Here is the output of the live blink detector along with my commentary:

Improving our blink detector

This blog post focused solely on using the eye aspect ratio as a quantitative metric to determine if a person has blinked in a video stream.

However, due to noise in a video stream, subpar facial landmark detections, or fast changes in viewing angle, a simple threshold on the eye aspect ratio could produce a false-positive detection, reporting that a blink had taken place when in reality the person had not blinked.

To make our blink detector more robust to these challenges, Soukupová and Čech recommend:

  1. Computing the eye aspect ratio for the N-th frame, along with the eye aspect ratios for N – 6 and N + 6 frames, then concatenating these eye aspect ratios to form a 13 dimensional feature vector.
  2. Training a Support Vector Machine (SVM) on these feature vectors.

Soukupová and Čech report that the combination of the temporal-based feature vector and SVM classifier helps reduce false-positive blink detections and improves the overall accuracy of the blink detector.


In this blog post I demonstrated how to build a blink detector using OpenCV, Python, and dlib.

The first step in building a blink detector is to perform facial landmark detection to localize the eyes in a given frame from a video stream.

Once we have the facial landmarks for both eyes, we compute the eye aspect ratio for each eye, which gives us a singular value, relating the distances between the vertical eye landmark points to the distances between the horizontal landmark points.

Once we have the eye aspect ratio, we can threshold it to determine if a person is blinking — the eye aspect ratio will remain approximately constant when the eyes are open and then will rapidly approach zero during a blink, then increase again as the eye opens.

To improve our blink detector, Soukupová and Čech recommend constructing a 13-dim feature vector of eye aspect ratios (N-th frame, N – 6 frames, and N + 6 frames), followed by feeding this feature vector into a Linear SVM for classification.

Of course, a natural extension of blink detection is drowsiness detection which we’ll be covering in the next two weeks here on the PyImageSearch blog.

To be notified when the drowsiness detection tutorial is published, be sure to enter your email address in the form below!


If you would like to download the code and images used in this post, please enter your email address in the form below. Not only will you get a .zip of the code, I’ll also send you a FREE 17-page Resource Guide on Computer Vision, OpenCV, and Deep Learning. Inside you'll find my hand-picked tutorials, books, courses, and libraries to help you master CV and DL! Sound good? If so, enter your email address and I’ll send you the code immediately!

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289 Responses to Eye blink detection with OpenCV, Python, and dlib

  1. Marc Boudreau April 24, 2017 at 12:39 pm #

    Hi Adrian,
    Looks very interesting as usual!

    I saw on Twitter that you got dlib working on Raspi.
    Are you planning a tutorial on installing dlib on Raspi?

    • Adrian Rosebrock April 25, 2017 at 11:52 am #

      Correct — the dlib + Raspberry Pi install blog post will go live next week (May 1st, 2017).

  2. Eric Sobczak April 24, 2017 at 4:01 pm #

    This looks great. I like the fact that you explain the science behind it all. Should we be using Python 2.7 or 3.0?

    • Adrian Rosebrock April 25, 2017 at 11:51 am #

      You can use either Python 2.7 or Python 3.

  3. RAVIVARMAN RAJENDIRAN April 25, 2017 at 4:44 am #

    Hi, Thanks for the code.
    When i run the code, i get following two lines in output and not opening any video.

    [INFO] loading facial landmark predictor…
    [INFO] starting video stream thread…

    • Adrian Rosebrock April 25, 2017 at 11:48 am #

      What type of camera are you using?

      • haili April 26, 2017 at 3:42 am #

        Hi Adrian,Very thanks for you code.
        But when i run the code,i I also can’t open any video.I use the USB camera of Logitech…

        • Adrian Rosebrock April 26, 2017 at 6:49 am #

          It sounds like your version of OpenCV was compiled without video support. I would suggest re-compiling and re-installing OpenCV using one of my tutorials.

          • Rachna Chadha July 18, 2019 at 12:34 pm #

            Hi – I had used the same link for installing openCV 4 but using the provided mp4 makes pi hang . I am
            not sure what I am missing

      • Jorge April 26, 2017 at 9:40 pm #

        Hi Adrian. I have the same issue with the blink detection:
        [INFO] loading facial landmark predictor…
        [INFO] starting video stream thread…
        and then the prompt.
        (The code for “real-time-facial-landmarks” works fine)

        • Adrian Rosebrock April 28, 2017 at 9:41 am #

          Hi Jorge — please check my reply to “haili” above. You’ll want to compile OpenCV with video support so you can access your webcam.

          • Jorge April 30, 2017 at 2:35 am #

            Hi Adrian. Thanks for your great job!!
            I found the cause of the issue. I missed to uncomment two lines of code:
            66: vs = VideoStream(src=0).start()
            68: fileStream = False
            (So we can use the built-in webcam or USB cam, as you say in the blog (in your instructions are lines 63 and 64 but in the downloaded code are 66 and 68)
            I Hope this could help HAILI and RAVIVARMAN RAJENDIRAN
            Thanks a lot for this blog

          • Adrian Rosebrock May 1, 2017 at 1:26 pm #

            Congrats on resolving the issue Jorge, thank you for sharing.

  4. Nurulhasan April 25, 2017 at 8:00 am #

    Really great job..
    Face recognition also possible??.

    • Adrian Rosebrock April 25, 2017 at 11:46 am #

      You typically wouldn’t use facial landmarks directly for face recognition. Instead you would try Eigenfaces, Fisherfaces, and LBPs for face recognition (covered inside the PyImageSearch Gurus course. Otherwise, you would look into OpenFace.

      • faeze September 3, 2018 at 7:14 am #

        Hi.Thanks for this post.so useful.
        I have a question.openface just install on linux or we can install it on windows??

  5. Christian April 25, 2017 at 9:12 am #

    Very cool! Great post. Thanks!!

    • Adrian Rosebrock April 25, 2017 at 11:45 am #

      Thanks Christian, I’m glad you enjoyed it!

  6. JBeale April 25, 2017 at 7:32 pm #

    Great article, this is really impressive. In my case, my eye aspect ratio never goes much above 0.3 no matter how wide I open my eyes. Also, I missed some blinks with the 3 frame setting, maybe your frame rate is higher than mine. This is what works better on my system:

    EYE_AR_THRESH = 0.23 # was 0.3

    • Adrian Rosebrock April 25, 2017 at 8:59 pm #

      Thanks for sharing! As I mentioned in the post, it might take a little tweaking depending on the frame processing rate of the system.

  7. JBeale April 25, 2017 at 8:03 pm #

    It is interesting to note that the green outlines around my eye always seem to show both eyes are roughly the same amount open, even when one eye is completely wide open and the other eye is entirely shut. Looks like the facial landmark detector (HOG) is making some assumption that the face should be symmetric, so both eyes should be about the same.

    • Adrian Rosebrock April 25, 2017 at 9:01 pm #

      The face detector is HOG-based. The facial landmark predictor is NOT HOG-based. Instead it interprets these landmarks as probabilities and attempts to fit a model to it. You can read more about the facial landmark detector here.

  8. Arzoo April 26, 2017 at 4:21 am #

    Hi Adrian,
    thanks for the detailed tutorial!
    I downloaded the zip file and executed the required command in terminal.
    I got this error:
    RuntimeError: Unable to open shape_predictor_68_face_landmarks.dat
    I’m using a macOS Sierra.
    can you please help me figure this out.

    • Adrian Rosebrock April 26, 2017 at 6:49 am #

      Make sure you are executing your Python script from the same directory as the .dat file. Based on your error message, it seems like your paths are incorrect.

      • Arzoo May 6, 2017 at 7:41 am #

        Got it. Thank you!

      • Jack November 1, 2017 at 9:50 am #

        Hi Adrian
        thanks for the detailed turorial!
        I have the same error like Arzoo,but I work on win10,dlib18.17,opencv3.1,python3.4.5
        now I do not know how to solve it.
        can you please help me solve the problem.

        • Adrian Rosebrock November 2, 2017 at 2:24 pm #

          Hi Jack — I don’t officially support Windows here on the PyImageSearch blog, I highly recommend you use a Unix-based environment such as Linux or macOS to study computer vision. In either case it looks like your path to the shape prediction model is incorrect. Double-check your paths and ensure you are using Windows path separators (‘\’) instead of Unix path separators (‘/’).

  9. wallace April 26, 2017 at 11:34 pm #

    Hi Adrian Rosebrock
    Thanks for your great work. But I’m using a windows OS. So how can I install the dlib library correctly for the facial landmark detection?

    • Adrian Rosebrock April 28, 2017 at 9:38 am #

      Hi Wallace — I don’t cover Windows here on the PyImageSearch blog. I recommend using Unix-based operating systems such as macOS and Ubuntu for computer vision development. IF you would like to install dlib on Windows, please refer to the official dlib site.

    • Tarun April 29, 2017 at 3:13 am #

      Hi wallace,

      I used pip install dlib and that worked. I am able to use dlib in my code

    • Tarun April 29, 2017 at 3:19 am #

      Hi Adrian,

      Firstly, thank you so much. Your blog is of immense help for a computer vision enthusiast like me.

      A bit off topic – now days I am playing with YOLO to get real time object detection. I am trying to implement this in Python but without any success. Do you plan to cover this up?

      • Adrian Rosebrock May 1, 2017 at 1:41 pm #

        I’ll be covering YOLO along with Faster R-CNNs and SSDs inside Deep Learning for Computer Vision with Python. Object detection with deep learning is still a very volatile field of research. I’ll be discussing how these frameworks work and how to use them, but a pure Python implementation will be outside the scope of the book.

        Keep in mind that many state-of-the-art deep learning frameworks for object detections are based on forks of libraries like Caffe or mxnet. The authors then implement custom layers. It will likely be a few years until we see these types of object detectors (or even the building blocks) naturally existing in a stable state inside Keras, mxnet, etc.

  10. Gökhan Aras April 30, 2017 at 3:52 am #

    Thanks Adrian,

    you are a wonderful man

    this blog very good

    • Adrian Rosebrock May 1, 2017 at 1:25 pm #

      Thank you Gökhan, I really appreciate that! 🙂

  11. jon May 1, 2017 at 5:03 am #


    could you please make this clear :

    A = dist.euclidean(eye[1], eye[5])

    why eye[1], eye[5] ? in dlib eye landmarks to which eye[1], eye[5] is referring ?

    • Adrian Rosebrock May 1, 2017 at 1:19 pm #

      These are the individual indexes of the (x, y)-coordinates of the eyes. These indexes map to the equation in Figure 4 above (keep in mind that the equation is one-indexed while Python is zero-indexed). Furthermore, you can read more about the individual facial landmarks in this post.

  12. Shivani Junawane May 2, 2017 at 12:25 pm #

    vs.show() no such function found..

    This is the error i am getting.. I am able to run the code with built in video.. but not using laptop camera.. please resolve this issue..

    • Adrian Rosebrock May 3, 2017 at 5:46 pm #

      There is no function called vs.show() anywhere in this blog post. Did you mean vs.stop()?

  13. Firatov May 4, 2017 at 6:35 am #

    Hi Adrian,

    Great post! Tested this one with mobile phone (iPhone) and it works okay. dlib detection is a bit problematic on iphone camera so sometimes it doesn’t detect blinks because of bad lighting.

    I like the simple idea behind it. I tried to apply this idea to “eyebrow raise” detection mechanism but the ratio is not changing as drastically as eye ratio. Do you maybe have suggestion or idea to apply the same idea to eyebrow raising or any other facial gesture?

    • Adrian Rosebrock May 4, 2017 at 12:30 pm #

      Keep in mind that the eyebrow facial landmarks are only represented by 5 points each — they don’t surround the eyebrow like the facial landmarks do for the eye so the aspect ratio doesn’t have much meaning here. I would monitor the (x, y)-coordinates of the eyebrows, but otherwise you might want to look into other facial landmark models that can detect more points and encapsulate the entire eyebrow.

      • Roy Gustafson June 6, 2017 at 3:08 pm #

        Hi Adrian, thanks for this guide. As of now, I’m trying to use this system for wink detection. Right now I’m gathering data, but what I’ve determined is that both EAR’s decrease by something like 40% no matter which eye winks. Then I determine which EAR decreased more, and which decreased less. I may hard code it, if I can generalize it to a ratio indicating a wink, then a difference indicating WHICH eye is winking. From there, I need to make sure it doesn’t give me false positives for blinks and squints (although squints might be impossible to rule out).

        But this project has given me a lot to go off of! Thanks so much

  14. Jinwoo May 7, 2017 at 3:40 am #

    Hi Adrian,

    I’m having a problem running this code. It says
    “detect_blinks.py: error: the following arguments are required: -p/–shape-predictor”
    Can you please help me solve this error?

    • Adrian Rosebrock May 8, 2017 at 12:27 pm #

      Hi Jinwoo — I would suggest that you read up on command line arguments before continuing.

      • Mohammed Salman September 10, 2017 at 11:38 am #

        Do you know what is the issue here ?

        I’ve read what you have linked.. Don’t seem to find the solution here.

        • Adrian Rosebrock September 11, 2017 at 9:09 am #

          Please read the article again. It provides a discussion on command line arguments and how to use them. The problem is that you’re not specifying the --shape-predictor argument to your script.

  15. Ketan Vaidya May 8, 2017 at 12:24 pm #

    Hi! Great tutorials on the site! Just to give you a suggestion;
    Could you also use an IR lighting rig to light up the subject at night time? Because most webcams have the capability to detect IR.

  16. Ayush Karapagale May 28, 2017 at 1:11 am #

    its very slow isnt there any way to fasten it ??…..

    • Adrian Rosebrock May 28, 2017 at 1:28 am #

      What are the specs of the computer you are using to execute the code? This code can easily run a modern day laptops/desktops.

      • ayush karapagale May 28, 2017 at 2:25 am #

        i have apple macbook air… but i am doing a project that requires raspberry pi only because i have to make the device portable… i ahe tried increasing the gpu to 256 mb but its still the same

        • Adrian Rosebrock May 31, 2017 at 1:32 pm #

          I will be writing an updated blog post that provides a number of optimizations for blink detection on the Raspberry Pi within the next couple of weeks. Stay tuned!

      • ayush karapagale May 28, 2017 at 2:26 am #

        in the video you are able to run the program fast… can u
        please tell how ??

  17. reza June 4, 2017 at 8:02 pm #

    Hi .I want to write a program that count people(footfall counting).can you help me?tnx

  18. Dheeraj June 13, 2017 at 7:10 am #

    Hi Adrian,

    Its not accurate at all, even if i move my eyes and don’t blink it count it as blinked. why ?

    • Adrian Rosebrock June 13, 2017 at 10:51 am #

      It sounds like you need to adjust the EYE_AR_THRESH variable as discussed in the post.

  19. zjfsharp June 20, 2017 at 3:12 am #

    It’s amazing! Thank you, Adrian Rosebrock! I want to use this to my fatigue detection experience.

    • Adrian Rosebrock June 20, 2017 at 10:46 am #

      Thanks, I’m happy to hear you found the project helpful! 🙂 Best of luck on your fatigue detection work.

  20. shubhank rahangdale June 23, 2017 at 3:10 pm #

    Hi Adrian

    if fileStream and not vs.more(VideoStream(src=0).start()):
    TypeError: more() takes exactly 1 argument (2 given)

    This is the error i am getting.. I am able to run the code with built in video.. but not using laptop camera.. please resolve this issue..

    • shubhank rahangdale June 23, 2017 at 3:23 pm #

      Thanks, I found the bug..

      • Adrian Rosebrock June 27, 2017 at 6:40 am #

        Congrats on resolving the issue Shubhank!

        • shubhank November 12, 2017 at 10:28 am #

          hi… Adrian
          Could you share your content number so that I can contact you for my project details and idea .

  21. Adrian Perez June 28, 2017 at 9:32 am #

    Hello! Adrian, thanks for share your experience.

    how do you add a graphic or plot with the eye blink data?

    could you share this code to?


    • Adrian Rosebrock June 30, 2017 at 8:19 am #

      Are you trying to plot the EAR over time? If so, I would suggest using matplotlib, Bokeh, or whatever plotting library you feel comfortable with.

      • junryy November 19, 2019 at 7:03 am #

        hi,Adrian,i use other video with my eyes, but the demo don’t detect blink. how to do work out the problem?

  22. Tommy Tang July 13, 2017 at 5:32 pm #

    Hi Adrian,

    Thank you so much for sharing and I followed all your steps to create a blink rate monitoring as well as a head tilting monitoring using some other data among the 68 points. All works pretty well but I found that the predictor will fail to predict the accurate eye contour when the object is wearing optics. Do you have any suggestion for that? Cause I know in openCV haar cascade there seems to be a specific classifier for eyes with glasses. Will there be a specific predictor built for this case?

    • Adrian Rosebrock July 14, 2017 at 7:23 am #

      That’s a great question. If the driver is wearing glasses and the eyes cannot be localized properly, you would likely need to create a specific predictor. Another option might be to try an IR camera, but again, that would also imply having to train a custom predictor. I’ve never tried this method with the user wearing glasses.

  23. Johan July 18, 2017 at 6:10 am #

    HI Adrian, I want to convert this to C++ code, can you please point me right direction, Thank you

    • Alan October 15, 2018 at 8:31 am #

      Have you read about Face Landmark Detection on Dlib website in section C++ examples?

  24. Chamath August 11, 2017 at 3:25 am #

    Hi thank for your amazing tutorial. But i got an error and i can’t resolve it. can you please help me.

    [usage: faceland.py [-h] -p SHAPE_PREDICTOR_68_FACE_LANDMARKS.DAT
    faceland.py: error: the following arguments are required: -p/–shape_predictor_68_face_landmarks.dat]

    Thank You.

    • Adrian Rosebrock August 14, 2017 at 1:20 pm #

      Please read the comments before you post. I have already answered this question in reply to “Jinwoo” above.

      • jasmeet November 11, 2018 at 1:22 pm #

        please elaborate it i didn’t get the solution.
        thanking you

        • Adrian Rosebrock November 13, 2018 at 4:51 pm #

          Read my tutorial on argparse and command line arguments. If you read the tutorial you will understand command line arguments and be able to resolve the problem.

  25. Arighi August 16, 2017 at 3:31 pm #

    Hey Adrian, i really love your tutorial. It helped me a lot for finising my project. But i have some problem making it automatically set the threshold based on the person’s default opened eye EAR (different race, different eye EAR).

    Like i set it for 0.2, ot worked great for me, but not for my chinese friend. It detected his eyes closed. So i have to manually edit the threshold. Is there any way to make it more dynamic?

    • Adrian Rosebrock August 17, 2017 at 9:07 am #

      In short, not easily. I would suggest collecting as much EAR data as possible across a broad range of ethnicities and then using that as training data. Secondly, keep in mind what I said regarding in the “Improving our blink detector” section. You can treat the EAR as a feature vector and feed them into a SVM for better accuracy.

    • gopi November 5, 2019 at 3:07 am #

      Can you try capturing the EAR in the initial 2-4 seconds (maybe pick the maximum EAR obtained in that time frame) and then instead of going by the absolute EAR of 0.3 or 0.2 etc. you could go by % drop in the max EAR as a qualifier for drowsiness. That way you don’t have to change the EAR threshold at all. Please note that while an EAR threshold of 0.3 worked for me it didn’t do that well for my wife and we both are Indians and from the same region too. So, in all probability capturing the user’s base EAR in the initial few seconds and then measuring the drop% could be a way to go.

      Adrian, it would be great to hear your view on this.


  26. Jack August 17, 2017 at 4:42 am #

    Hello there:
    I have a quick question about the facial landmark detection: if only a partial face is presented, is it possible to detect any part of the face elements, e.g. only one eye? Or do we need to retrain the data set to just detect an eye? Thanks.

    • Adrian Rosebrock August 17, 2017 at 9:02 am #

      Keep in mind that facial landmark detection is a two phase process. First we must localize the face in an image. This normally done using HOG + Linear SVM or Haar cascades. Only after the face is localized can we detect facial landmarks. In short, you need to be able to detect the face first.

      • Jack August 23, 2017 at 2:30 pm #

        Thanks for the reply. If we know that the image is only for an eye area, is it possible to use facial landmark to just detect the feature or outline of the eye? Thanks.

        • Adrian Rosebrock August 23, 2017 at 3:39 pm #

          Unfortunately, no. The facial landmark detector assumes you are working with the entire face. If you had just eye images and wanted to localize the eye you would need an eye detector + a trained shape predictor for the eye region.

  27. J-F Duquette August 18, 2017 at 9:28 am #

    Hi Adrian,

    Many thanks for you sharing your knowledge. I’m trying to use your video file and everything is loading without errors but the video doesn’t show at all. I have follow your tutorial on how to install OpenCV and i have install video lib. I found to the web that i could be something with FFMPEG ?

    Thanks for your help

    • Adrian Rosebrock August 21, 2017 at 3:48 pm #

      It’s hard to say what the exact issue could be, although it sounds likely that your system does not have the proper video codecs installed to read your video. I would suggest installing FFMPEG then re-compiling and re-installing OpenCV.

  28. Fernando J. August 19, 2017 at 6:52 pm #

    Hi Adrian, thank you very much for the wonderful tutorials and courses that you present each time.

    First question: Could this flicker detector be used as liveness detection in any facial recognition system?.

    Second question: Do you plan to prepare a tutorial on some effective mechanism for the liveness detection in a facial recognition system?.

    Thank you!.

    • Adrian Rosebrock August 21, 2017 at 3:42 pm #

      1. Yes, this could be used for liveness detection, although I would recommend using a depth camera as well.

      2. I’ll add liveness detection as a future potential blog post, thank you for the suggestion.

  29. Ankit September 8, 2017 at 1:12 pm #

    line 116, its give invalid syntax error, please help,, i am using this code in Windows, and use Webcam of my PC.

    • Adrian Rosebrock September 11, 2017 at 9:24 am #

      What is the exact error you are getting? Did you use the “Downloads” section of this tutorial to download the code instead of copying and pasting it?

  30. Mohammed Salman September 9, 2017 at 9:29 pm #

    Hi Adrian,

    I’m an Engineering student. I am getting the following errors after de-commenting Line 62:

    usage: detect_blinks.py [-h] -p SHAPE_PREDICTOR [-v VIDEO]
    detect_blinks.py: error: the following arguments are required: -p/–shape-predictor

    Please help! (I am going to take your 21 day crash course, very exicited sir!)

    Best Regards.

    • Adrian Rosebrock September 11, 2017 at 9:16 am #

      Hi Mohammed — please see my previous reply to your comment. You need to read up on command line arguments. The issue is you’re not supplying the --shape-predictor switch.

  31. Carlos September 19, 2017 at 1:22 am #

    Hi Adrian, I installed OpenCV from this link, I followed all the steps https://www.pyimagesearch.com/2016/04/18/install-guide-raspberry-pi-3-raspbian-jessie-opencv-3/ and I got this right
    $ source ~/.profile
    $ workon cv
    $ python
    >>> import cv2
    >>> cv2.__version__
    But with this code I get an error: ImportError: No module named spicy (and imutils and cv2 )
    I made a ‘test’: when I write source~/.profile->workon cv->python->import cv2, I dont have any error, but when I write ->import cv2 on the python shell (3.4.2) I get the error No module named cv2
    (I’m sorry for my english)
    Good job and thanks sooo much

    • Adrian Rosebrock September 20, 2017 at 7:18 am #

      I’m bit confused. You were able to install OpenCV 3.1 on your Raspberry Pi and access it via the command then. But then you try to import SciPy and you cannot access it? It sounds like you didn’t install SciPy on your Raspberry Pi:

      • Carlos September 21, 2017 at 7:34 pm #

        Adrian, thanks for your reply, I installed the scipy. When I open the terminal and I write->source~/.profile->workon cv->python->import cv2 there’s no any error, but when I open the Python shell and I write import cv2, then it shows “No module named cv2”. I get this error only in the Python Shell, not in the terminal, it’s like:
        $ source ~/.profile
        $ workon cv
        $ python
        >>> import cv2
        >>> (Here there’s no problem)

        Python Shell: (3.4.2)
        >>>import cv2
        “No module named cv2”

        Thank you Adrian, regards!!!

        • Adrian Rosebrock September 22, 2017 at 8:56 am #

          Can you clarify what you mean by “Python shell”? Are you referring to the GUI version of Python IDLE? If so, the GUI version of IDLE does not support Python virtual environments and it will not work. Please use the terminal or use Jupyter Notebooks.

          • Carlos September 22, 2017 at 8:57 pm #

            Yeah!!! exactly, now I understand, then I’ll use Jupyter.
            Again, thanks so much Adrian,

  32. Jack September 26, 2017 at 7:52 pm #

    Hey! How do you contact EAR if the framework returns 8 points for the eye?

    • Adrian Rosebrock September 27, 2017 at 6:45 am #

      You might not be able to. How many landmarks are detected around each eye?

  33. Reza October 1, 2017 at 3:52 am #

    Ur code cant work for multiple faces at the same time right?
    The counter variable gets violated

    • Adrian Rosebrock October 2, 2017 at 9:46 am #

      Correct, this code is intended for a single face. You can update it to work with multiple faces by tracking each face and associating a counter with each face.

  34. Carlos October 8, 2017 at 1:12 am #

    Hi Adrian, At first thank so much, you’re the best.
    I have a question, when I execute the program, I get this message (After INFO)


    ** (Frame:32335): WARNING **: Error retrieving accessibility bus address: org.freedesktop.DBus.Error.ServiceUnknown: The name org.a11y.Bus was not provided by any .service files

    I received this warning after install opencv 3.3, before, I was executing the program with opencv 3.1 and I never received any warning, do you know what is it about?
    Thank you

    • Adrian Rosebrock October 9, 2017 at 12:30 pm #

      It’s important to understand that that is is a warning and not an error. The message has no impact on your ability to execute the code or obtain the correct results.

      To make the message go away run:

      $ sudo apt-get install libcanberra-gtk*

      Then re-compile and re-install OpenCV>

      • Carlos October 9, 2017 at 10:48 pm #

        Ok, thank you

  35. Reza Ghoddoosian October 13, 2017 at 6:46 pm #

    Hi and thanks for the content
    i get this error:
    Unable to stop the stream: Inappropriate ioctl for device
    do you know how i should sole it?

    • Reza Ghoddoosian October 13, 2017 at 7:05 pm #

      btw it does not work to read from a file , th e webcam version works

      • Adrian Rosebrock October 14, 2017 at 10:36 am #

        Unfortunately I’m not sure what the error is here. Can you try using the FileVideoStream class?

  36. Chris October 29, 2017 at 8:26 am #

    Hi Adrian thanks for the content!

    I have this error when running in my command prompt:
    Unable to open shape_predictor_68_face_landmarks.dat

    Both my script and the dat. file is in the same directory(desktop),do you know how to make it work?

    • Adrian Rosebrock October 30, 2017 at 2:59 pm #

      Hi Chris, you must specify the proper path to the file. You also must make sure permissions for files are set.

      • Chris November 1, 2017 at 10:18 am #

        Hi Adrian, thanks for the reply, the error has been resolved.
        Thanks again for the great content!

  37. Salman November 22, 2017 at 12:37 pm #

    Thank you for this great article.
    I’m working on images of eyes (just eyes, no face) to find out the drowsiness. Is it possible to use dlib for the case the eyes are cropped out of the face? Or you have better suggestions.

    Thank you

    • Adrian Rosebrock November 25, 2017 at 12:45 pm #

      Hey Salman — you would need to train your own custom shape predictor for just the eyes. The method outlined in this blog post requires the entire face to be detected which in turns allows the eyes to be localized.

      • John January 11, 2019 at 2:43 pm #

        Hi, Adrian. Why don’t you use your own custom shape predictor for eye blink detection?

        • Adrian Rosebrock January 16, 2019 at 10:19 am #

          Perhaps I’m not understanding your question — we are using a shape predictor for eye blink detection in this tutorial.

  38. Daniel Obeng December 6, 2017 at 12:50 pm #

    Hello Adrian, this works amazingly well. I’m currently using it for a project in college where we need to map an eye blink to the time within the video that it occurred. Do you think you can help me modify the code so that I can also log the time (i.e the time within the video) that the blink occurred? Thanks!

    • Daniel Obeng December 6, 2017 at 12:53 pm #

      Also, I was hoping you can show me how to modify the code so that it doesn’t show the video but just works in the background.

      • Adrian Rosebrock December 8, 2017 at 5:06 pm #

        Hey Daniel, can you elaborate more on what you mean by “time within the video”? Secondly, while I’m happy to help point you in the right direction and provide suggestions please keep in mind that I publish all tutorials here on PyImageSearch free of cost. I’m simply too busy to take on additional customizations. I hope you understand.

  39. Narmi December 19, 2017 at 3:57 am #

    Sir your explanation is easily understandable..Can this will be implement using c++ in opencv?

    • Adrian Rosebrock December 19, 2017 at 4:15 pm #

      You can use this method in any programming language provided you can localize the eye region and apply the EAR algorithm.

  40. Andrea December 20, 2017 at 4:55 pm #

    Hey Adrian, just a quick note to say thanks – we have used this as a base to build upon for a blink based lie detection system for a project at university. (we have credited you, of course!)
    We found that blink detection is improved a lot if the EAR threshold is dynamically set to respond to the mean of recent EAR values. Also, getting some nice graphical output tracking EAR and counting blinks really helped with algorithm tuning.
    Anyway, thanks for a super readable code – I enjoyed playing around with it. 🙂
    Take care x

    • Adrian Rosebrock December 22, 2017 at 7:04 am #

      Congrats on the successful project, Andrea! The blink-based lie detection system sounds very interesting. Do you have a writeup of the report so I can learn more about it?

  41. Ashish Sharma January 6, 2018 at 3:56 am #

    I am using windows
    after running this code i got an error
    detector = dlib.get_frontal_face_detector()
    AttributeErrors: ‘module’ object has no attribute ‘get_frontal_face_detector’

    Please help

    • Adrian Rosebrock January 8, 2018 at 2:55 pm #

      That is odd…which version of dlib are you using?

      • ASHISH Sharma January 9, 2018 at 1:36 am #

        We are using dlib 18.17.100

        • Adrian Rosebrock January 10, 2018 at 1:04 pm #

          Thanks for sharing the version information. Unfortunately I’m not sure what the error would be in this case. I would suggest posting on the official dlib forums. Sorry I couldn’t be of more help here!

  42. Hadi January 7, 2018 at 11:25 am #

    Hi Adrian
    I need your .exe of program. Can you give it to me?

  43. raghav January 29, 2018 at 11:13 am #

    usage: detect_blinks.py [-h] -p SHAPE_PREDICTOR [-v VIDEO]
    detect_blinks.py: error: argument -p/–shape-predictor is required
    i got this error..how to solve it….

    • Adrian Rosebrock January 30, 2018 at 10:12 am #

      Please read the comments before posting. See my reply to “Jinwoo” on May 7, 2017 (as well as others). Make sure you read on on command line arguments and how they work.

  44. Andrew February 5, 2018 at 2:51 am #

    I’m having a problem running this code. It says
    “detect_blinks.py: error: the following arguments are required: -p/–shape-predictor”
    Can you please help me solve this error?
    I saw your reply to “Jinwoo”…but I don’t understand that.
    Please explain more thoroughly.

    • Adrian Rosebrock February 6, 2018 at 10:20 am #

      This script is meant to be executed via the command line. Open up the command line, navigate to where you downloaded the source code + example video, and then execute the script, exactly as I do in the blog post:

      It’s okay if you are new to command line arguments but take the time to educate yourself on them before continuing.

  45. mv^2 February 5, 2018 at 2:53 am #

    HI Adrian
    error occurred.

    usage: detect_face_parts.py [-h] -p SHAPE_PREDICTOR [-r PICAMERA]
    detect_face_parts.py: error: the following arguments are required: -p/–shape-predictor
    I watched your command “command line arguments”
    i dont know how to set up an argument and path.

    • Adrian Rosebrock February 6, 2018 at 10:19 am #

      See my reply to “Mohammed Salman” on September 9, 2017.

  46. Dhanush February 5, 2018 at 6:55 am #

    It works fine for file stream but when on executing for video stream (using USB camera) following error occurs

    Traceback (most recent call last):
    File “detect_blinks.py”, line 82, in
    frame = imutils.resize(frame, width=450)
    File “/root/.virtualenvs/cv/lib/python3.5/site-packages/imutils/convenience.py”, line 69, in resize
    (h, w) = image.shape[:2]
    AttributeError: ‘NoneType’ object has no attribute ‘shape’

    • Adrian Rosebrock February 6, 2018 at 10:17 am #

      It sounds like OpenCV cannot access your webcam. Take a look at this post where I discuss OpenCV NoneType errors and how to resolve them.

    • Hager June 3, 2019 at 7:08 pm #

      Hi, dhanush. I experienced this same error…..if u solved it please let me know how. =) thank you.

  47. Mkhuseli February 8, 2018 at 1:31 am #

    Hei Adrian. Good work. After obtaining the yes, is the a function that i can use to crop both eyes?

    • Adrian Rosebrock February 8, 2018 at 7:50 am #

      You can crop the eyes using NumPy array slices. Compute the bounding box of the coordinates and use rectangular coordinates to extract the eyes.

  48. jathusan February 13, 2018 at 1:59 pm #

    hi how can i implement eye blink detection in c#?
    is there any way??
    help me…

  49. rvk February 15, 2018 at 1:35 pm #

    hey Adrian…

    i need some help regarding my project

    i am thinking of implementing drowsiness detection using CNN using eyes in the wild data set.The model has to detect the eyes and if the eyes are closed for a certain period of time the model should give some indication to the driver.Firstly,is it possible in real time using CNN.whats the best way to train the model.
    I am not asking you for code..all i need is,what libraries should i use..how should i save the trained weights.can CNN work on webcam real time streaming.if so,how.?

    Thanks in advance. 🙂
    sorry for my bad english.

    • Adrian Rosebrock February 18, 2018 at 9:58 am #

      Is there a particular reason why you would want to use a CNN? Before even starting a project you should consider the reasoning behind “why”. The method proposed here doesn’t require a CNN and using deep learning could very easily become overkill. I’m also not familiar with the closed eyes in the wild dataset. Do you have a link to it?

  50. Carlos February 19, 2018 at 4:25 pm #

    Hi, Adrian, and thank you, I have a question, I wanna make an <> based in this blink detection. I add some code lines, removing the average of the EAR for both eyes. I replaced it by something like that: If (leftEAR>rightEAR:left wink) if(leftEAR<rightEAR:right wink), (if leftEAR=rightEAR and <EYE_AR_THRESH, then it's a normal blink), but it always shows the same EAR value for each eye, despite I close just one eye. Thanks!!!!

  51. Ashish Sharma March 12, 2018 at 8:52 am #

    Hi adrian,
    Your blog is superb
    i can run a program succesfully but i also want to make an exe. so how to make .

    • Adrian Rosebrock March 14, 2018 at 1:04 pm #

      Unfortunately Python + OpenCV together does not lend well to create an executable file. You would need to distribute the source code.

  52. Jeru Shalom Barlos March 13, 2018 at 5:52 pm #

    Hi , i have a following error. How can I resolve this sir?

    usage: detect_blinks.py [-h] -p SHAPE_PREDICTOR [-v VIDEO]
    detect_blinks.py error: argument -p/–shape-predictor is required.

    I have already installed the necessary libraries thru pip install dlib , and all of the requirement, still getting errors. Please help 🙁

  53. Gani March 30, 2018 at 9:52 am #

    Someone please guide me – is there any pure javascript library that does eye blink detection?

    • Adrian Rosebrock March 30, 2018 at 10:49 am #

      I don’t think so. Did you do any research on it?

  54. Boris April 2, 2018 at 12:29 am #

    we would like to use Python 3.6 with Spyder!
    can we use this program for making blink detector which u posted?

    • Adrian Rosebrock April 4, 2018 at 12:30 pm #

      Yes, but you’ll want to make sure the Python interpreter you are using with Sypder can access OpenCV and any other required libraries.

  55. Boris April 9, 2018 at 12:50 am #

    Thank you for replying : )

    I got a problem while installing the dlib. I failed to install dlib even though I searched almost web and blog.

    Im not sure but many say it is difficult to download the dlib on Window.

    Is there any way that I can use ur code without dlib?

    I’d like to make a eye blink detection with Python but without dlib. Do you have any ideas?

    Thanks a lot

    • Adrian Rosebrock April 10, 2018 at 12:15 pm #

      For this particular code you would need dlib. I have not used Windows in many years so I’m unfortunately not sure what would be causing the issue with the dlib install.

  56. Hi April 12, 2018 at 2:13 pm #

    Why using VideoStream and threads and not VideoCapture? Thanks!

    • Adrian Rosebrock April 13, 2018 at 6:42 am #

      The VideoStream classes leverages threading and reduces I/O latency. See this blog post for more information.

      • Hi April 13, 2018 at 10:25 am #

        And dont you have a problem when killing the thread in python?
        If I run your code, when I press q, the terminal lags and I have to shut down and open the terminal again

        • Adrian Rosebrock April 16, 2018 at 2:38 pm #

          I have not ran into issues with the thread gracefully exiting.

  57. marcos April 13, 2018 at 10:22 am #

    Hi! Trying to implement something similiar but I want to detect winks, any idea? Try to do the same but for each eye but its not working
    Also, this particular method counts when you look down, do you know how can I adjust more?


    • Adrian Rosebrock April 16, 2018 at 2:39 pm #

      You can certainly detect winks, just compute the EAR for each eye and then track how long each eye has been closed for. As far as “looking down” you may want to adjust your camera placement or use a more advanced method for eye blink detection, perhaps one that uses multiple EAR inputs as a feature vector.

  58. seifeddine April 16, 2018 at 4:41 pm #

    hi Adrian;

    i runed u’r code and i get this error :

    AttributeError : WebCamVideoStream instance has no aattributr ‘more”

    • Adrian Rosebrock April 17, 2018 at 9:28 am #

      Make sure you install of “imutils” is up to date:

      $ pip install --upgrade imutils

  59. malo April 17, 2018 at 8:59 am #

    Hello! First I want to thank you, your tutorial have been of great help.

    I´m trying something similar but with smiles, if I measure the distance of points 49 and 55 (dist.euclidean(mouth[0], mouth[6])) I can detect a smile but the problem I have encounter is that the distance change depending of the distance to the web cam.

    Do you know if there is a way to normalize de distance of the points, making it not dependig of the distance to the camera?

    • Adrian Rosebrock April 17, 2018 at 9:15 am #

      Hey Malo — there are a few ways to approach this problem. Is there any particular reason you are relying strictly on the distance? You could attempt use an aspect ratio calculation here for the smile here as well. This would not make the system reliant on the distance.

      • malo April 17, 2018 at 2:09 pm #

        What do you mean with use an aspect ratio calculation?

        • Adrian Rosebrock April 17, 2018 at 4:25 pm #

          Refer to this blog post. We compute the “EAR” or “Eye Aspect Ratio”. You can do something similar with the mouth landmarks (perhaps a “Mouth Aspect Ratio”) just as a quick test. If that doesn’t work you can normalize the distance of the mouth by scaling it by the width of the face then trying to threshold on it.

          • Malo April 18, 2018 at 9:16 am #

            Sorry to bother you again.
            But how can I meassure the width of the face?
            It´s not the same problem. Gnna meassure the width of the face doing the distance between two points but thats gonna change depending of how far Im from the camera.

          • Adrian Rosebrock April 18, 2018 at 2:51 pm #

            You know the bounding box of the face so you can therefore compute the width of the face. You could also compute the width based off two opposing chin facial landmarks as well.

            If you divide the distance between your two mouth landmarks by the face width you end up with a ratio. This ratio will not change. Try it for yourself and see.

  60. malo April 17, 2018 at 10:00 am #

    yeah..but I couldn´t find an aspect ratio for the smile.
    Also if I can solve this I can track all the others point of the face and notice differents expressions

  61. Vamshi Reddy Pothuganti April 18, 2018 at 10:04 am #

    one single question why did you use imutils.video and imutils why do you want to publicize yourself when a new person is trying to develop a new component they want to try from scratch why do you want to gain a name when dlib is open source python is open source and ubuntu is also open source why are you doing like this i seriously want to use skiimage dlib numpy for the easy interface and easy understanding instead of your complicated words in the code so how should we proceed?

    • Adrian Rosebrock April 18, 2018 at 2:48 pm #

      Perhaps I’m not understanding your criticism here. The imutils library is open source. You can use it if you would like or not. That’s really your choice, just like it’s your choice if you want to use other open source libraries such as scikit-learn, dlib, NumPy, etc. It’s really up to you. The reason I used imutils is stated in this blog post — it contains my threaded implementation of the VideoStream class which is more efficient for frame reads.

  62. Vamshi Reddy Pothuganti April 18, 2018 at 10:44 am #

    I also want to get rid of imutils face_utils and argparse what is the best way to do that and what should i use instead of shape = face_utils.shape_to_np(shape) how can i get rid of this and also why did you use args = vars(ap.parse_args())

    • Adrian Rosebrock April 18, 2018 at 2:49 pm #

      If you want to get rid of “face_utils” you will need to implement it by hand in your own code. You can get rid of argument parsing as well but you should read this blog post first.

  63. lalo April 24, 2018 at 12:17 pm #

    Have you try make en executable of this code?

    • Adrian Rosebrock April 25, 2018 at 5:41 am #

      No, it would be a royal pain and not worth it. Trying to bundle together a Python app that includes the OpenCV bindings and system dependencies would be challenging to say the least.

  64. ASHISH Sharma April 25, 2018 at 4:55 am #

    Sir i want to hide a a frame windows please help me

    • Adrian Rosebrock April 25, 2018 at 5:16 am #

      Can you clarify what you mean by “hide a frame window”?

  65. Siang May 17, 2018 at 4:11 am #

    Hi, Dr.Adrian.
    I would like to thank you for the great tutorial, especially with clear explanations.
    i would like to ask is it possible to extract the (x,y) value from any of the point (P1 – P6) as shown in figure 3 ? If so, how should I extract the coordinate ?
    Thanks in advanced.

    • Adrian Rosebrock May 17, 2018 at 6:34 am #

      This blog post actually shows you how to extract the eye coordinates. Lines 94 and 95 extract the (x, y)-coordinates for both the left eye and right eye. You can then loop over each of the respective sets of points.

  66. evan May 22, 2018 at 2:25 pm #

    Hey Adrian. Thanks for your knowledge and enthusiasm–
    Im (newish to python) and trying to get the blinks to trigger short midi sequences using pygame. I got it to work per se, but the video is paused during playback and then resumes after. Ideally it wouldnt, improving the timing of the next trigger (so they could potentially overlap.) I tried a couple threading situations, but couldnt seem to get the right configuration. Am i on the right track at least?

    • Adrian Rosebrock May 23, 2018 at 7:15 am #

      Yes, threading would be your best bet here. My guess is that you are forgetting to make your thread a daemon:

      Which will ensure it runs in the background.

  67. Arfizur rahman May 22, 2018 at 4:06 pm #

    Hi, Dr.Adrian.

    Many many thanks for this tutorial, It really helped me a lot.
    Can you make a tutorial on improving the blink detector, as you mentioned in the “Improving our Blink detector”.(13-dim feature vector, SVM).

    Thanks again.

    • Adrian Rosebrock May 23, 2018 at 7:14 am #

      Hey Arfizur — thank you for the suggestion. I have made note of it but I cannot guarantee if or when I may write the tutorial.

  68. priya May 25, 2018 at 1:26 am #

    when i placed my mobile infront of webcam it actually counting the blink of my pic on mobile phone lol!!!

  69. Ben May 30, 2018 at 6:59 am #

    Hi Adrian, great tutorial! When I tested it, my EAR was ~0.2 when my face is close to camera, and was increasing and eventually went to ~0.35 when I move my face back from camera (eyes open in both cases), so if I set the treshhold to 0.2, it will not work when my face is not close to camera. Is there a way to handle this? I assume I can multiply EAR by a constant ratio based on the size width of my face shape compared to the width of the entire photo, but I am not sure.

    • Adrian Rosebrock May 31, 2018 at 5:07 am #

      You can normalize the EAR by the width (or height) of the bounding box surrounding your face. Give that a try.

  70. Gwendy May 30, 2018 at 10:32 am #

    Nice tutorial!

    • Adrian Rosebrock May 31, 2018 at 5:04 am #

      Thanks Gwendy, I’m glad you enjoyed it 🙂

  71. Ben May 31, 2018 at 4:37 am #

    Thanks for the tutorial!

    • Adrian Rosebrock May 31, 2018 at 4:50 am #

      Thanks Ben, I’m glad you found it helpful!

  72. Madhurish June 21, 2018 at 1:12 am #

    Hi Adrian,
    We can apply above code for certain types of people on whom the threshold(0.3) perfectly matches. But if I want apply on large dataset containing many videos then the threshold will not work for all videos. So is there any method from which we can set threshold so that it works for all videos.
    I thought of one idea like we can store EAR for each frames and then analyse them to set threshold.
    Anyways you are doing a great work as these topics are not easy to understand but due to these blogs you made these topics easily understandable.


    • Adrian Rosebrock June 21, 2018 at 5:34 am #

      See my comments in the blog post. I would suggest taking a temporal approach and taking the EAR over N frames, forming a feature vector, and then training a machine learning model, like an SVM over it. This will make the system more resilient and will not require a threshold.

      • Madhurish June 22, 2018 at 1:54 am #

        Thanks, I will try.

  73. Taufiq Ari W July 11, 2018 at 6:32 am #

    I want to ask about the value of 0.05 / 0.1 / 0.15 / 0.2 /, 0.25. that’s what value is it? and what units? then use the formula how?
    thank you Mr. Adrian Rosebrock

  74. Brij July 12, 2018 at 3:13 am #

    Hey bro,

    Awesome work ..I and my team started from a scratch and by looking all your blogs finally after 4 days and 3 full nights I am able to count my blinks!!!..so happy!!…I modified your code little bit as I have used my android camera connected to server so i have not use FileVideoStream instead i used urllib and also i made some other changes like the dataset one and it took me 2 days just to install all the libraries ..

    but when the code successfully compiled i forgot all the nights that we spent .

    Thanks bro!..now i will take this one a slight ahead!..cheers!

    • Adrian Rosebrock July 13, 2018 at 5:09 am #

      Congrats Brij! I’m so excited for you and your team!

  75. Richa Agrawal July 20, 2018 at 5:52 am #

    hello sir, thanks a lot for providing code, which is really helpful, Sir I am getting an error in the code and cannot understand how to correct it so if you could help it would really be great.

    The error is shown below:

    usage: detect_blinks.py [-h] -p SHAPE_PREDICTOR [-v VIDEO]
    detect_blinks.py: error: the following arguments are required: -p/–shape-predictor

    • Adrian Rosebrock July 20, 2018 at 6:20 am #

      You need to supply the command line arguments to the script. See this post for more details.

  76. Dr. Bernard July 20, 2018 at 11:16 am #


    This is VERY cool! May I ask the following:

    1. I see about 100 comments here – is the link at the top to the eye blink counter still the best link?

    2. Can I set the parameters so that it does not create visible circles around the eyes… I would like to use this for normal videoconferencing without the distraction of the green circles…

    Thank you for creating such an important program

    • Adrian Rosebrock July 21, 2018 at 9:15 am #

      1. Which link are you referring to? Please be more specific.

      2. You can comment out Lines 106 and 107.

  77. hasib July 24, 2018 at 2:38 am #

    hey Adrian i need only eye_detector (HOG) + a trained shape predictor for the eye region.can you help me o build it

    • Adrian Rosebrock July 25, 2018 at 8:07 am #

      I do not have a shape predictor for just the eye region. You would need to take a look at the dlib documentation on how to train your own custom shape predictors.

  78. Saeed August 15, 2018 at 8:52 am #

    Hi DR.Rosebrock

    Thanks for your great post.Your post has been a great help for my project.
    Could you explain this paragraph?

    “Computing the eye aspect ratio for the N-th frame, along with the eye aspect ratios for N – 6 and N + 6 frames, then concatenating these eye aspect ratios to form a 13 dimensional feature vector.”

    How do I implement this for eye blink detector?

    Thanks and respect for your post.

    • Adrian Rosebrock August 15, 2018 at 9:22 am #

      You would maintain the eye aspect ratios for the previous set of N frames. Then you would concatenate them into a single list and pass them through a trained model, such as an SVM or Logistic Regression model.

  79. yuan August 20, 2018 at 2:27 am #

    hello sir, thank you for this great tutorial! I can run the “real-time-facial-landmarks”, but when I run the “blink-detection”, it told me that ” AttributeError: ‘module’ object has no attribute ‘FACIAL_LANDMARKS_IDXS'”. How can I solve the problem?

    • Adrian Rosebrock August 22, 2018 at 10:00 am #

      This was caused in the latest release of imutils v0.5. I’ll be fixing it in within the next few days with a release of imutils v0.5.1, but in the meantime just change “FACIAL_LANDMARKS_IDXS” to FACIAL_LANDMARKS__68_IDXS and it will work.

      • Adrian Rosebrock August 23, 2018 at 9:21 am #

        v0.5.1 of imutils has been released. If you upgrade your install of imutils you will no longer see the error 🙂

  80. Jasen August 21, 2018 at 4:25 am #

    Error coming like this…

    usage: detect_blinks.py [-h] -p SHAPE_PREDICTOR
    detect_blinks.py: error: the following arguments are required: -p/–shape-predictor

    • Adrian Rosebrock August 22, 2018 at 9:36 am #

      You need to supply the command line arguments to your script. It’s okay if you are new to them, but you NEED to read up on them before you continue.

      • Jasen August 23, 2018 at 12:29 am #

        I already went through it. Actually i am doing this program in python shell in windows. I am not getting what to do with this argument here. Argument values we can pass when we try to run the program in terminal, right? I am not doing in that way. I have shape_predictor_68_face_landmarks.dat file in same directory in which main program exist. So i am not sure the need to give argument commands in the program. Opening the file using dlib.shape_predictor alone would do it, right?

        • Adrian Rosebrock August 23, 2018 at 9:18 am #

          Don’t launch a Python shell and execute the script. Instead, just open your command line, navigate to where you downloaded the code, and execute the script using the Python executable. Do not use the Python shell itself. If you read the tutorial I linked you to in my previous comment it will help clear up your confusion on command line arguments. There is no need to edit any file. There is no need to edit or open any code. Just change directory to where you downloaded the script and execute it.

      • Jasen August 23, 2018 at 1:32 am #

        Thanks i got it…

  81. Ben August 21, 2018 at 9:26 am #

    Hi Adrian, I have a question about dlib point detection. I installed it and everything works ok, except when my eyes aren’t facing straight in front of camera, in some frames it detects eye points wrong, so the points are moving above my real eye points and back again to the right values, and it keeps changing every frame although I don’t move at all. So my question is is there a way to detect those error cases in order to exclude them from calculations?

    • Adrian Rosebrock August 22, 2018 at 9:32 am #

      That is odd behavior for sure. Are you using the “Downloads” section of my post to download the code + examples? Or are you using your own implementation?

      • Ben August 24, 2018 at 8:18 am #

        I just built the latest dlib version for the iPhone, and it is the same: if you smile fast too “hard”, so your eyes are almost closed, the detector starts swinging points to your brows and back. Is there a way to detect those cases or even better remove them?

        • Adrian Rosebrock August 24, 2018 at 8:27 am #

          I haven’t encountered such a situation. That would be a good question for Davis, the creator of dlib. I would ask him on the dlib GitHub project page.

  82. Ben August 23, 2018 at 5:41 am #

    I used https://github.com/zweigraf/face-landmarking-ios this github project to test it on my iPhone, which uses dlib too. The case I’m talking about is when you move your head down, so top part of eyes is a little bit hidden by brows.

  83. Jasen August 23, 2018 at 7:39 am #

    error coming like this…..
    AttributeError: module ‘imutils.face_utils’ has no attribute ‘FACIAL_LANDMARKS_IDXS’

    then it will show AttributeError: module ‘imutils.face_utils’ has no attribute FACIAL_LANDMARKS__68_IDXS

    I am using imutils 0.5.1

    • Adrian Rosebrock August 23, 2018 at 9:19 am #

      It sounds like you’re not actually using imutils 0.5.1 then. v0.5.1 of imutils includes both FACIAL_LANDMARKS_68_IDXS along with an alias variable FACIAL_LANDMARKS_IDXS that points to FACIAL_LANDMARKS_68_IDXS. I know from your previous comments that you’re struggling with executing the script and likely have some confusion regarding Python package basics. I would suggest triple and quadruple checking your install of the imutils package and after that, triple and quadruple checking that your Python environment is indeed importing v0.5.1 of imutils.

      • Jasen August 24, 2018 at 1:13 am #

        Thank You so much Adrian. I could resolve it. Actually i was installing imutils with the command ‘pip install imutils’. Thought it would get me the latest version. Isn’t it like that? Anyway now i given command ‘pip install imutils==0.5.1’, and problem is resolved. Thanks again.

        • Adrian Rosebrock August 24, 2018 at 8:32 am #

          If imutils is already installed it won’t upgrade the package. You would have needed:

          $ pip install --upgrade imutils

  84. jinxing September 6, 2018 at 10:54 pm #

    Hi Adrian,When I type the following command in the terminal, I get this error.I have configured the environment according to your blog.If you can answer me, I will be very grateful.

    import cv2
    ModuleNotFoundError: No module named ‘cv2’

  85. Preetha September 10, 2018 at 7:26 am #

    Hey Adrian,
    It would be great if you could help me out with the link to install opencv 3 and python on Windows 10, and also let me know how Opencv can access the webcam on my laptop, and what changes have to be done in my code
    Thank you

    • Adrian Rosebrock September 11, 2018 at 8:13 am #

      Hey Preetha — I do not officially support Windows here on the PyImageSearch blog. I highly recommend you use a Unix-based machine like Linux (Ubuntu) or macOS. I provide a number of different install tutorials to get you started as well. I hope that helps!

  86. Petter September 30, 2018 at 7:41 pm #

    Is there a way to find the pupil of the eyes and track it using this kind of method?

    • Adrian Rosebrock October 8, 2018 at 10:52 am #

      I haven’t tried this method, but I know other PyImageSearch readers have gotten it to work. I would suggest starting there.

      • Petter October 8, 2018 at 8:38 pm #

        Thanks for replying that quick and also for giving me a starting point.

  87. MANAS SIKRI October 17, 2018 at 9:58 am #

    First of all I would like to thank you for your blog.It was of great help.
    I wanted to detect the blinks for different people in the frame separately.How can I do so?

    • Adrian Rosebrock October 20, 2018 at 7:55 am #

      Thanks Manas, I’m glad you’re enjoying the blog!

      As for multi-person blink detection, that’s totally possible, but will require reworking the code quite a bit. You’ll want to detect all faces in a frame, loop over them, and then maintain separate counters for each of them, allowing you to determine when either of them have blinked. You may also want to perform simply object tracking so you can easily associate IDs with people.

      • MANAS SIKRI October 22, 2018 at 6:21 am #

        Thank you, for giving me some starting point.I would try to implement this.

  88. Shivam Gupta October 24, 2018 at 8:18 am #

    Hey! Adrian, I want to make a project which will detect face and update the attendance in the database. But with simple face detection there is an ambiguity that it can detect fake images too, so in order to differentiate between the fake and real image I got the idea of blinking eye face detection tutorials by you, from git hub . Is it possible to detect blinking eye face and update attendance in the database. Or is there any other alternative to make my project without this ambiguity.

    • Adrian Rosebrock October 29, 2018 at 2:01 pm #

      What you’re referring to is actually part of a larger field of study called “liveliness detection”. I would suggest reading a few papers on liveliness detection and finding one that is sufficient for your project.

      • Piyush Nimoria February 2, 2019 at 8:21 am #

        Agreed Shivam, what if some one records video of your eyes blinking and use it, the blink would still count right.

        • Adrian Rosebrock February 5, 2019 at 9:35 am #

          Correct — that is why I suggested Shivam take a look at “liveliness detection” algorithms.

  89. sungmin November 7, 2018 at 2:51 am #

    hello Andria
    We use your code, but webcam does not open.
    Which program do we need to install?
    We use every program that you install.

    • Adrian Rosebrock November 10, 2018 at 10:20 am #

      Does the script automatically exit? Does it produce an error message? Any other information you can provide would be helpful.

  90. Tan November 23, 2018 at 10:13 pm #

    Hi Adrian, can I use a wireless sport camera instead of webcam/usb camera/ raspberry pi camera?

    • Adrian Rosebrock November 25, 2018 at 9:05 am #

      Yes, provided that the cv2.VideoCapture function supports your wireless stream.

  91. Jerry Cogswell December 27, 2018 at 3:23 pm #

    Hi, Adrian, I’ll bet this would be useful as part of a lie detector system used with other clues. That’s assuming that the person is not a pathological liar who is as comfortable with lying as with breathing. Such use has probably been done, ya? BTW did you know that the lie detector was invented by Dr. Marston who created the Wonder Woman comic? There’s a movie about it.

  92. Marina December 27, 2018 at 5:46 pm #

    I’m confused >.> Are we supposed to be training a SVM on the feature vectors in real time or something? <.<

    • Adrian Rosebrock January 2, 2019 at 9:46 am #

      We don’t actually train a SVM in this tutorial. I recommended using a SVM if you wanted to improve the method. You would train the SVM offline and then use it in real-time after its been trained.

  93. ِAfnan January 6, 2019 at 9:26 am #

    Hello …

    I have only one question ..

    Can OpenCV be used to identify the iris and integrate it into Python?

    • Adrian Rosebrock January 8, 2019 at 7:01 am #

      OpenCV itself can facilitate building an algorithm to detect the iris of the eye; however, OpenCV does not include any built-in functions that automatically detect the iris. You would need to actually implement the algorithm itself.

  94. Vas January 31, 2019 at 4:47 am #

    Hey Andrian,
    Thank you. Your tutorial was helpful, but we have a small problem. We are using logi-tech webcam for video streaming, the video is slow what we need to do.

    • Adrian Rosebrock February 1, 2019 at 6:53 am #

      Are you running the code on a laptop or a Raspberry Pi? What are your system specs and how large is the input frame?

  95. Piyush Nimoria February 2, 2019 at 4:58 am #

    Hi Adrian,

    Thanks for a great article. When I am running your code, the blink count is incremented even though I move here and there and keep my eyes open. How can I make it more accurate?
    Also can this code be implemented in java?

    Would really appreciate your response

    • Adrian Rosebrock February 5, 2019 at 9:37 am #

      You should tune the EAR threshold value. As far as improving the model see my notes in the post about a rolling window of EAR values + SVM.

  96. Aaron Packham February 7, 2019 at 6:31 pm #

    Hi Adrian, I am doing a University project and I wanted to incorporate a fatigue detection camera within the product I am making. Unfortunately I do not know anything about OpenCV, Python, and dlib or coding for that matter. Is there anyway you could help me?

    • Adrian Rosebrock February 14, 2019 at 3:01 pm #

      You will need to have at least some knowledge of programming to be successful in your project. If you’re new to computer vision and OpenCV, that’s fine, but you’ll need to read Practical Python and OpenCV first — that book will teach you the basics.

  97. syed February 12, 2019 at 9:31 am #

    i really want to thank you for such a good explanation and references

    • Adrian Rosebrock February 14, 2019 at 1:16 pm #

      Thanks Syed, I really appreciate that 🙂

  98. Sumanth R February 20, 2019 at 12:18 pm #

    sir thank you for the code but i am facing a problem in install dlib it gave me run time error and instructed me to install Cmake its not installing properlly sir can you please help me out please

    • Adrian Rosebrock February 20, 2019 at 12:26 pm #

      Make sure you follow my dlib install instructions to help you get dlib configured and installed properly.

  99. shaobing February 21, 2019 at 1:26 am #

    I found that if I didn’t blink but moved my head back and forth, Blinks’ value would also increase, meaning the program thought I blinked.

  100. AJ March 5, 2019 at 7:15 am #

    Hi Adrian, can I run this on raspberry pi? if not, are you going to post one for raspi?

  101. Hamdi March 6, 2019 at 4:13 am #

    Hi Adrian,

    How can I implement blink detection algorithm and your centroid tracker each other ? I want to create system be like finding faces ,finding id’s and counting ids blinks . How can I do it can you help me ?

    • Adrian Rosebrock March 8, 2019 at 5:48 am #

      I would suggest you take your time and start slow. I assume you have been able to get them both to run independently, correct?

      If so, the next step is to start start incorporating facial landmark detection into the centroid tracking code. Detect landmarks for each face and visualize them. Make sure they are working.

      From there, extract the eye regions.

      Then move on to computing the EAR.

      Finally, add in the variables to detect blinks.

      Take your time, go slow, and debug often.

      And if you need additional help, refer to Practical Python and OpenCV so you can learn the fundamentals of computer vision and image processing. That book shows basic examples of how to build computer vision applications. I’m confident it will help you here as well.

  102. aditya verma March 10, 2019 at 1:03 pm #

    Hey Adrian,
    This code works like a charm with people who do not wear spectacles, but is gives very ambiguous results for people wearing spectacles. Is there any way to fix this?

  103. Hamod March 18, 2019 at 2:47 pm #

    Hi Adrian.

    You are awesome. I have learn a lot from you; and actually I am looking for gaze/eye tracking code, do you post any?

    Thank you very much.

    • Adrian Rosebrock March 19, 2019 at 9:57 am #

      Sorry, I do not currently have any tutorials on that topic.

  104. Ziyad March 28, 2019 at 12:05 am #

    Hello Adrian, thanks for your useful articles.

    is there any option to runs blink detection without using dlib packages? if exist, what should i prepare or do to make it?

  105. Karan ahuja Ahuja April 10, 2019 at 10:37 pm #

    Hi Adrian,

    Thank you a bunch.

    If I hold a real photo in front of webcam and if I shake the photo,
    Then a blink is falsely detected.

    How can I go about solving this?

  106. Sam April 22, 2019 at 4:44 am #

    Hey I’m trying to add functionality of detecting when a tongue is sticking out but I’m having problems making it work. I’m trying to take the color above the lower edge of the lower lip and the color below it which are supposed to be pink above and skin color below and then when a tongue is sticking out its pink both above and below. But the color difference is not distinguishable enough. Do you have any other ideas?

    • Adrian Rosebrock April 25, 2019 at 9:03 am #

      Interesting project. I don’t have any tutorials on that topic but I’ll consider it for the future. Thank you for the suggestion Sam!

  107. Ananya Vaish May 8, 2019 at 10:33 pm #

    Hi Adrian, this post has really helped a lot. Can you please help me with Mouth Aspect Ratio for smile detection? In what standard range should the ratio lie in order to stop depending from person to person ?

  108. Sumiya May 9, 2019 at 7:43 pm #

    Hello Adrian, Thanks for making us more learned. Can you provide the code that represents EAR in real-time as Figure 5. I really want it and I hope you will join my requist.

    • Adrian Rosebrock May 15, 2019 at 3:15 pm #

      I do not have such code, that is a figure from the paper. You can use matplotlib to generate such a plot though.

  109. Eren May 20, 2019 at 7:06 am #

    Thanks for the great tutorial.

    I have a question about creating a video stream from the video file. In my project, I am getting the video from a post request as a byte array. However, I couldn’t figure how FileVideoStream can use my byte array to read the video. I searched on several resources, but all solutions require first saving the file to the disk and then read from the disk again. I think this is an overhead. Can you suggest me a way to do this without saving the video to the disk?

    Many thanks from now,

    • Adrian Rosebrock May 23, 2019 at 9:47 am #

      How is the byte array formatted? Can you access it normally via “cv2.VideoCapture”?

      • Eren May 31, 2019 at 6:45 pm #

        The shape of the array is (size of the file in bytes,). For example for a video of 1 mb, when I look at itsarray.shape, I see (1000000,) .

        I can’t access it with cv2.videoCapture as well. I looked at its documentation and saw that it can read video only from the path or the webcam.

        In my case, there is a video in the memory(with byte array) and I want to use this video with opencv methods. Have you ever encountered with a similar situation?

        • Adrian Rosebrock June 6, 2019 at 8:39 am #

          It seems like the frame/image array has been flattened in some manner. It’s hard to say what the problem is, I have never encountered that issue before. My only suggestion would be to ensure you have installed the proper video codecs for the video file and that OpenCV supports those codecs.

  110. Alex May 21, 2019 at 12:40 am #

    Hi Adrian! I am just wondering why I got this error constantly: error: (-215:Assertion failed) size.width>0 && size.height>0 in function ‘cv::imshow’; I searched it and found that maybe the path is not found. However, when I execute the EAR I could still get and only get ONE pair of values (namely, left, right and average), this should not be the case right?

    As your code is written for command line and I am writing in jupyter, I changed the path variable as a dictionary, is that matters?

    • Adrian Rosebrock May 23, 2019 at 9:42 am #

      It sounds like OpenCV cannot access your webcam or video file. Double-check your file paths if you are using a video file. If using a webcam, make sure OpenCV can access it.

  111. ahmet öztürk May 22, 2019 at 1:51 am #

    hello adrian. I want to use the program that counts eye blinks to use in a research. I used the demo of this program. How can I get this program which gives averages of blinking numbers over a given time period. Can I also get an information about this program with technical information? Thanks

    • Adrian Rosebrock May 23, 2019 at 9:37 am #

      The blog post itself serves as documentation for the technical information. If you choose to use it for research make sure you cite the tutorial.

  112. Abhijeet July 18, 2019 at 4:23 am #

    Hi Adrian,
    Thanks for the great Job. I am trying to recognize blink detection having faces with spectacles on but could not recognize it. As far as i understand face landmark predictors detect facial, points regardless of whether you are wearing spectacles or not.So i am unable to get where it fails.could you please suggest what steps are supposed to be taken.

  113. Pham August 4, 2019 at 1:34 am #

    Hi Adrian,

    The method works well on the images that need to have the face. In my dataset, I just have the left eye and right eye (similar to Figure 3 above) captured by the camera that attached to two eyes of the person.

    Can you give me some advice on how to prepare data and train to detect 6 those points?

    My dataset contains thousands of images as in this blog in “Figure 3: The 6 facial landmarks associated with the eye.”

  114. Laura Giraldo August 13, 2019 at 10:50 am #

    Hi Adrian. Thank you for the code!. But I have a problem. I have OpenCV on a virtual machine, then, I have my project on jupyter. How can I excute the command from this virtual machine?. Thank you so much!

    • Adrian Rosebrock August 16, 2019 at 5:40 am #

      I would recommend you simply execute the code via the command line. While I’m happy to provide the code and tutorial for free I cannot debug your dev environment.

  115. Owen lee September 1, 2019 at 6:22 am #


    Thank you for your ability

    • Adrian Rosebrock September 5, 2019 at 10:32 am #

      Thanks Owen.

  116. Deepak September 4, 2019 at 5:07 am #

    Hi Adrian,

    The blog is quite impressive and worked in first try after following the steps mentioned. Great!

    The example identifies blinks even if we put an photo/ snap in front of video. We want that when photo is placed in front of video then blinks should not be considered.

    What we need to achieve this.


  117. Arslan Ali September 23, 2019 at 10:46 pm #

    Hi Adrian,

    Thanks for the great project. I’m trying to modify it in order to create 3-functions. First one detects only Single-blinks ( which is already done there by you ).
    The second function detects only 2-consecutive blinks and the third function counts only 3-consecutive blinks. But i’m unable to come up with any logic to do so. Can you help me out please.

  118. Eder October 9, 2019 at 8:27 am #

    Hi Adrian,

    I am working on a project to drive a device through eye tracking. I could perfectly detect the eyes and pupils based on their material. I can’t identify the correct region the user is looking at. Is there a way to define regions on the screen to be identified based on the user’s eyes?

    • Adrian Rosebrock October 10, 2019 at 10:14 am #

      That’s a calibration-related problem. It’s more challenging than it appears on the surface. Start by focusing your research efforts on “camera and eye calibration”.

  119. Khayam khan November 1, 2019 at 6:41 am #

    How can we find out drowsiness using eye blinks..
    i mean the average rate of eye blinking is 13 to 20 per min so we have to wait for the whole minute to count the eye blinks…

  120. Sanjay J November 5, 2019 at 10:39 am #

    I am using a Raspberry Pi 3. The RPi freezes when I execute

    python detect_blinks.py –shape-predictor shape_predictor_68_face_landmarks.dat

    I am using it within a venv using workon cv.

    Is it the right device or should I use a Windows 10 laptop with Python ? I was unable to install dlib. But will try again.

    • Adrian Rosebrock November 7, 2019 at 10:17 am #

      If you’re using a Raspberry Pi you should follow this tutorial instead. Specifically, swap in Haar cascades for face detection as they will be faster on the RPi.

  121. Harsha R S December 10, 2019 at 2:58 am #

    This project is quite impressive. So even I am developing the same project with some additional features such as displaying a timer like how you display the EAR and I want to display the timer till 60 seconds , after that the timer restarts and the number of blinks in a duration of 60 seconds are stored in-order to send a notification to the user of the system if the blink rate or the blinks fall below the normal blink rate which we initialize to some default value. So can I get some assistance in developing the same?.
    Hoping for the solution for my queries. (1. Display Timer 2. Send a notification to the user)
    thank You.

  122. Jason K December 11, 2019 at 12:55 am #

    Hi Adrian,
    Excellent topics and good coding tutorials! Just to let you know our left and right eye blink differently. Quite astounding to see it with your code. With many compliments.

    • Adrian Rosebrock December 12, 2019 at 10:06 am #

      Thanks Jason!

  123. Anthony The Koala December 30, 2019 at 12:52 am #

    Dear Dr Adrian,
    In your earlier reply “Adrian Rosebrock April 17, 2018 at 9:15 am” someone mentioned about smile detection. I would like to know/extend this to (a) different kinds of smiles such as closed mouth/showing teeth and (b) frowns and (c) sadness.

    Question please:
    Is the aspect ratio calculation mentioned in the earlier reply the minimum requirement for all variations of smile, frowns and sadness? Are additional methods needed to capture all variations of smile, frown and sadness.

    Thank you,
    Anthony of Sydney


  1. Detecting eye blinks with Python – Full-Stack Feed - April 24, 2017

    […] Learn how to detect blinks, count blinks, and recognize blinks in video streams using OpenCV and Python. Read more […]

  2. Drowsiness detection with OpenCV - PyImageSearch - May 8, 2017

    […] weeks ago I discussed how to detect eye blinks in video streams using facial […]

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  1. If you have a question, read the comments first. You should also search this page (i.e., ctrl + f) for keywords related to your question. It's likely that I have already addressed your question in the comments.
  2. If you are copying and pasting code/terminal output, please don't. Reviewing another programmers’ code is a very time consuming and tedious task, and due to the volume of emails and contact requests I receive, I simply cannot do it.
  3. Be respectful of the space. I put a lot of my own personal time into creating these free weekly tutorials. On average, each tutorial takes me 15-20 hours to put together. I love offering these guides to you and I take pride in the content I create. Therefore, I will not approve comments that include large code blocks/terminal output as it destroys the formatting of the page. Kindly be respectful of this space.
  4. Be patient. I receive 200+ comments and emails per day. Due to spam, and my desire to personally answer as many questions as I can, I hand moderate all new comments (typically once per week). I try to answer as many questions as I can, but I'm only one person. Please don't be offended if I cannot get to your question
  5. Do you need priority support? Consider purchasing one of my books and courses. I place customer questions and emails in a separate, special priority queue and answer them first. If you are a customer of mine you will receive a guaranteed response from me. If there's any time left over, I focus on the community at large and attempt to answer as many of those questions as I possibly can.

Thank you for keeping these guidelines in mind before submitting your comment.

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