if you're reading them in with dir('*.imageextension') and with your file name scheme then it should already be in order. if not sortrows() would work for a
Files = dir('*.pic');
for i =1:length(Files)
filenames(i,1) = {Files(i).name};
end
sortedFiles = sortrows(filenames);
this works because you're zero padding the single digit numbers. if not then you can use the _ to parse out the min,sec, and msec and create an array that has the time in one unit and then use sort() to get the order. Use that to re-arrange your image sequence.
