write a function to detect movement in a video in matlab

main.m
function detect_movement(filename)

% Read the video file
vidObj = VideoReader(filename);

% Get information about the video
vidWidth = vidObj.Width;
vidHeight = vidObj.Height;
nFrames = vidObj.NumberOfFrames;

% Define a threshold for motion detection
threshold = 25;

% Read the first frame
frame1 = read(vidObj, 1);

% Convert the frame to grayscale
frameGray1 = rgb2gray(frame1);

% Initialize the loop variables
maxDiff = zeros(1, nFrames);
movingPixels = zeros(vidHeight, vidWidth, nFrames);

% Loop over all frames in the video
for iFrame = 2 : nFrames
    
    % Read the current frame
    frame2 = read(vidObj, iFrame);
    
    % Convert the frame to grayscale
    frameGray2 = rgb2gray(frame2);
    
    % Compute the absolute difference between the two frames
    diff = abs(frameGray1 - frameGray2);
    
    % Apply the threshold to detect movement
    movingPixels(:, :, iFrame) = diff > threshold;
    
    % Compute the maximum pixel difference for this frame
    maxDiff(iFrame) = max(max(diff));
    
    % Set the current frame as the previous frame for the next iteration
    frameGray1 = frameGray2;
    
end

% Display the maximum pixel difference for each frame
plot(maxDiff);
title('Maximum pixel difference between consecutive frames');

% Display the pixels that indicate movement in the video
movingPixels = sum(movingPixels, 3) > 0;
imshow(movingPixels);
title('Pixels that indicate movement in the video');

end
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