Issue with colormap when displaying an image extract from an animated gif file

I extract an image from an animated gif file with the following code :

GIF_file = dir([PathName, '*velocity*.gif']);
[im, map] = imread([GIF_file.folder, '\', GIF_file.name], 'frames', num);

Then i want to display it :

figure;
imshow(im)
colormap(map)

All is good when "num" (i.e. the frame number in the gif file) is set to 1 :

Now, when "num" is set to a number > 1, here is the result (num = 7) :

I don't understand what happens...

Please, is anybody is able to help me to have same color when num > 1 than when num = 1 ?

Thanks

Answer 1

[Mikaël LE GRAND]

Ok, iget it myself :

It seems that when we do (num <> 1)

GIF_file = dir([PathName, '*velocity*.gif']);
[im, map] = imread([GIF_file.folder, '\', GIF_file.name], 'frames', num);

'map' is always the colormap of the first image of the animated GIF. So, it's better to do :

infos = imfinfo([GIF_file.folder, '\', GIF_file.name], 'gif');
[im, map] = imread([GIF_file.folder, '\', GIF_file.name], 'frames', num);
imshow(im)
colormap(infos(num).ColorTable)

In this way, i get the good result for each frame of the animated GIF.