Here's a snippet to import a video in MATLAB and average all frames.
nf=video.NumberOfFrames;
avg = zeros([video.Height video.Width 3]);
for f = 1:nf
avg = avg + (1/nf).*im2double(read(video,f));
end;
I get a bit of a boost (200%) by using a parfor
parallel for loop:
nf=video.NumberOfFrames;
avg = zeros([video.Height video.Width 3]);
parfor f = 1:nf
avg = avg + (1/nf).*im2double(read(video,f));
end;