Hi, please if I have 500 I want to do like this for all the images I need a " for "but I don't how, thank you for help

a=imread('image\0.jpg');
r=a(:,:,1);
v=a(:,:,2);
b=a(:,:,3);
couleur=(r+v+b)/3;
save('img\couleur\0.mat','couleur');

Answer 1

[Azzi Abdelmalek]

for k=0:500
  a=imread(sprintf('image\%d.jpg',k));
  r=a(:,:,1);
  v=a(:,:,2);
  b=a(:,:,3);
  couleur=(r+v+b)/3;
  save(sprintf('img\couleur\%d.mat',k),'couleur');
end

[olfa abdalah]

it generate this error: Error using imread (line 348) Can't open file "image" for reading; you may not have read permission.

[Walter Roberson]

in_dir = 'image';
out_dir = fullfile(in_dir, 'couler');

for k = 0 : 499
  inname = fullfile(in_dir, sprintf('%d.jpg', k));
  a = imread(inname);
  couleur = mean(a, 3);
  outname = fullfile(out_dir, sprintf('%d.mat', k));
  save(outname, 'couleur');
end

The problem with Azzi's code is that inside sprintf(), \ has special meaning. His code could be fixed with

    a=imread(sprintf('image\\%d.jpg',k));

and

   save(sprintf('img\\couleur\\%d.mat',k),'couleur');

In my version, I avoid the issue by using the more robust fullfile()

[olfa abdalah]

thank you for help it works!