changing colormap of 10000 saved JPEG spectrograms

I have saved 10000 spectrograms as .jpeg images, in my hard drive, using the default "PARULA" colrmap. I want to change all of them to "AUTUMN" colormap. Is there any way to do that, without redrawing the spectrograms from audio from the scratch?

Answer 1

[Walter Roberson]

Use rgb2ind specifying the parabula map. Then ind2rgb that using the other color map.

[Sania Gul]

Tnk u so much.

I am doing it, but getting this error.

A=imread(fullfile(SourceFolder1,filenames1(count).name));
B=rgb2ind(A,'parula');

Error using rgb2ind

Expected MAP to be one of these types:

double, single, uint8, uint16, uint32, uint64, int8, int16, int32, int64

[Walter Roberson]

in_cmap = parula;
out_cmap = autumn;

A = imread(fullfile(SourceFolder1,filenames1(count).name));
B = rgb2ind(A, in_cmap);
C = ind2rgb(B, out_cmap);

[Sania Gul]

Tnk u so much. Its working perfectly fine now.

[Sania Gul]

Wait, wait, wait. All matrix value of A were laying between 0 to 255 in RGB plane, but the values of C are in range [0:1]. and diplayed as

Although the summer map displays perfectly, but I want it to be stored in range [0:255]. When I did

C=255*ind2rgb(B,out_cmap);

and display it by imshow(C), the result transformed to

[Walter Roberson]

 in_cmap = parula;
out_cmap = autumn;

 A = imread(fullfile(SourceFolder1,filenames1(count).name));
B = rgb2ind(A, in_cmap);
C = im2uint8(ind2rgb(B, out_cmap)) ;