Convert color video to grayscale video in MATLAB

Question

I am trying to do some operations on color video in MATLAB however, I am facing 2 problems:

• I am getting an error while converting color video to grayscale

Answer 1

Try it this way. This should do the trick. The code is self-explanatory.

 vid = VideoReader('xylophone.mpg');
 numImgs = get(vid, 'NumberOfFrames');
 frames = read(vid);
 obj=VideoWriter('somefile.avi');
 open(obj);

 for i=1:numImgs
     movie(i).cdata=rgb2gray(frames(:,:,:,i));
     movie(i).colormap=gray;
 end

 writeVideo(obj,movie);
 close(obj);