why does my colorbar look like this?

why does The colorbar looks gray all the time and matlab gives me this warning ?:

Warning: Error updating ColorBar. While setting the 'Limits_I' property of ColorBar: Value must be a 1x2 vector of numeric type in which the second element is larger than the first

> In defaulterrorcallback (line 12) In movegui (line 113) In images.internal.initSize (line 112) In imshow (line 305) In lena (line 13)

and here is the code:

A = imread('process/1.jpg');
B=blkproc(A,[8 8],'dct2')
imshow(log(abs(B)),[]), colormap(jet(64)), colorbar
figure
imshow(B);

B(abs(B)<10)=0;
figure
imshow(B);

C=blkproc(B,[8 8],'idct2');
round(C);

figure
imshow(C,[0 255]);

The image that i used :

the colorbar:

Answer 1

[Image Analyst]

You are not showing B and C with a colormap. They are on new figures and the colormap does automatically get copied onto completely new and different figures. Not only that, but they are different display ranges so even if you did they wouldn't look right.

Reissue the colormap command after you show the images on the new figures

colormap(jet(256));

[Hadeer tawfik]

Would you please check my modification , is that what you meant?

   A = imread('process/1.jpg');

B=blkproc(A,[8 8],'dct2')
figure
imshow(B);
figure
imshow(log(abs(B)),[]), colormap(jet(256)),colorbar

B(abs(B)<1)=0;
figure
imshow(B);
colormap(jet(256)),colorbar

C=blkproc(B,[8 8],'idct2');
round(C);

figure
imshow(C,[0 255]);

It is giving me these results:

[Image Analyst]

I'm not really sure what you want. This is what I get:

indexedImage = imread('1.jpg');
blockImage = blkproc(indexedImage, [8, 8], 'dct2')
displayImage = log(abs(blockImage));
cmap = jet(64);
imshow(displayImage, cmap, 'InitialMagnification', 400);
axis on;
movegui('northwest');
colorbar

figure
imshow(blockImage, 'InitialMagnification', 400);
colormap(cmap);
colorbar
axis on;
movegui('northeast');

blockImage(abs(blockImage) < 10)=0;
figure
imshow(blockImage, 'InitialMagnification', 400);
colormap(cmap);
colorbar
axis on;
movegui('southwest');

C = blkproc(blockImage,[8 8],'idct2');
C = round(C);
figure
imshow(C, [0 255], 'InitialMagnification', 400);
colormap(cmap);
colorbar
axis on;
movegui('southeast');

[Hadeer tawfik]

This is perfect, Thank you so much for your time