force colour of pixels with certain values to black when using a colormap with imagesc

Question

Mark Thompson 2022-10-31

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1839603-force-colour-of-pixels-with-certain-values-to-black-when-using-a-colormap-with-imagesc

评论： Mark Thompson 2022-10-31

Hi there,

I'm using imagesc to produce the following image (which is a plot of angular error for a given azimuth and elevation value):

Using caxis([0,10]); to constrain the range of valid values between 0 and 10 degrees is great. BUT, what I want to be able to do is assign another custom colour (e.g., white or black) to all values > 10. Can someone help me do this when plotting with imagesc?

I've tried defining a custom colourmap by setting the uppomost value to white for example, BUT, it sets all values that are 10 also to white (see below image). I need to retain those values...

So I'm looking for a way of forcing the colormap and colorbar to remain as above but only for values > 10 (the last image actually sets results = 10 also to white but I only want this for values greater than the maximum value of my colorbar), Like a thresholding operation.

Any assistance would be greatly received!

Many thanks.

Mark