Colorbar is to large in colormapeditor when using imshow

Hi

While working with the Matlab Image Processing Toolbox with MatLab R2012a I recognized a rather strange bug.

When displaying an image using image as plotting function and then opening the color bar editor, everything looks fine, except that the color scaling is not fitting correctly. To avoid this effect I normally use imshow, so that I can give color scale borders. When I open the colormapeditor in this mode the colorbar is way longer than the window, and this is quite cumbersome especially when one wants to adjust the colorbar with the colorflags. Unfortunately I cannot document the bug with pictures, since I don't know how to upload images to mathworks.com.

Is there a possibility to shrink the colorbar in "imshow-mode", so that it fits into the window?

Please find below the samplecode hopefully visualizing the problem.

Samplecode

cameraman = imread('cameraman.tif')
% Plot image with colortable
% first use of image()
figure;
image(cameraman)
axis equal
axis tight
colormapeditor

% first use imshow() with colorscaling
figure;
imshow(cameraman,[])
colormap('jet')
colormapeditor

Any help is appreciated

Thanks

Dominic

Answer 1

[Anand]

Dominic, I don't think this is a bug. The image command gives a 64x3 colormap, whereas the imshow command gives a 256x3 colormap. You can see this if you scroll to the last strip in the colorbar and hover the mouse over. It should say index 64 for the image command and 256 for the imshow command.

If you want the shorter colorbar with the imshow command, you need to just replace

colormap('jet')

with

colormap(jet(64))

Hope that helps.

Answer 2

[Dominic]

Hi Anand Thanks for your answer. It appears that you are totally right, I didn't realize that.

Thanks a lot for your help