How to conver folder (images) from GRB to Gary and save them in Output folder with the same original names?

i have this code which convert image to Gray and save it in current folder.

directory = dir('AM01AFS.jpg');
for i = 1 : size(directory,1)
 filename = directory(i).name;
 img = rgb2gray(imread(filename));
 imwrite(img, ['Gr_' filename]);
end

I need to convert folder (images) from GRB to Gary and save them in Output folder with the same original names? Any help Plz.

Answer 1

[Image Analyst]

You need to use fullfile() to make a name with the output folder prefixing the base file name:

outputFileName = fullfile(outputFolder, filename);
imwrite(img, outputFileName);

See the FAQ: http://matlab.wikia.com/wiki/FAQ#How_can_I_process_a_sequence_of_files.3F