how to take every fifth frame and then subtract it from the previous frame and then do the concatenation

i want to count every fifth frame from the video and want to subtract it from the previous frame from the video bby using optical flow and then have to concatenate all the frame in an video output

Answer 1

[C B]

In MATLAB, you can use the opticalFlow function to compute the optical flow between two consecutive frames of a video. This function returns a flow object, which contains information about the movement of the pixels in the video frames.

To count every fifth frame and subtract it from the previous frame, you can use a loop to iterate over the frames of the video. Inside the loop, you can use an if statement to check if the current frame is a multiple of 5. If it is, you can use the opticalFlow function to compute the optical flow between the current frame and the previous frame, and then subtract the current frame from the previous frame using the minus function.

Here is an example of how this code might look:

% Load the video into a video reader object
v = VideoReader('myVideo.mp4');

% Initialize a variable to store the previous frame
prevFrame = readFrame(v);

% Loop over the frames of the video
while hasFrame(v)
  % Read the current frame
  currFrame = readFrame(v);

  % Check if the current frame is a multiple of 5
  if mod(v.CurrentTime * v.FrameRate, 5) == 0
    % Compute the optical flow between the current and previous frames
    flow = opticalFlow(prevFrame, currFrame);

    % Subtract the current frame from the previous frame
    diffFrame = prevFrame - currFrame;

    % Concatenate the difference frame with the output video
    % (assumes you have already created an output video object named "out")
    writeVideo(out, diffFrame);
  end

  % Update the previous frame variable
  prevFrame = currFrame;
end

[PRACHI BHAGAT]

thanks i got it