# How to extract frames from a video in MATLAB?

7 views (last 30 days)
Anand on 2 Mar 2014
Commented: Image Analyst on 22 Apr 2019
Hi, I have managed to read the video frames, but how do i extract them?
videoPlayer = vision.VideoPlayer;
step(videoPlayer, videoFrame);
end
release(videoPlayer);
Any help would be appreciated
Thank you

Image Analyst on 2 Mar 2014
And what is the difference between a "video frame", and a "screen shot"? Please upload an image of each one so we can tell the difference. Do you mean like you want the task bar, parts of MATLAB, the figure toolbar, and any other programs that might happen to be running on your program, as well as parts of your desktop to be captured and saved?
Anand on 6 Mar 2014
Hi, can you please help me if this threshold is right, it doesn't seem to work when i run it. I have looked at alot of the paper on the site you recommended. you can recognise emotions if you set up a threshold in which it detects the distance between the corner points of the mouth and eyes. the method is Euclidean Distance.
A = smile expression B = Neutral expression
A < T < B
Euclidean Distance Threshold
a=max(eucl_dist_list);
b=min(eucl_dist_list);
if(b>a)
msgbox('UNKNOWN IMAGE','error','error');
else
imshow(gray2rgb(uint8(finalimg)));
end
Image Analyst on 6 Mar 2014
Sorry but it could be a complicated project and I can't afford to spend a lot of time helping you. Your code looks weird. The min is never going to be more than the max so that "if (b>a)" statement is useless - it will always do the imshow() and never ever do the msgbox(). There's no point at all to that code.

cp sahu on 30 Apr 2015
Edited: cp sahu on 30 Apr 2015
%pass the path of the video file with extension
for k = 1 : 40
%fill in the no of frames the video contains or anything less than that, The
%no of frames in a video can be identified by reading info about the video.
%i.e. the frame rate in fps, multiply it with video length in sec.
a=sprintf('Frame #%d.jpg', k); % store the name of the frame in 'a'.
imwrite(this_frame,a,'jpg'); % store the extracted frame under the compression scheme with third parameter.
end
Anirban Kundu on 22 Apr 2019
the imwrite function is not working. It says that "Unable to open file "Frame #1.jpg" for writing. You might not have write permission." I am using Matlab 2018a. Please provide me a solution
Image Analyst on 22 Apr 2019
What is the folder you're writing to? It's not under Program Files is it, because Windows does not allow you to write there.