How to select region on an intensity map(colormap)?

I have tried 'selectdata' function to select some region on my intensity plot (colormap), but it was not selecting the points. Instead, it was just taking the x and y values along a line in the selected region! The selected region was not highlighted as well (I used the option 'identify','on').

The 'selectdata' function was working very well on my plot. I am confusing why it is not working on intensity map (colormap)? Is there anyway to choose region from intensity map?

Answer 1

[Image Analyst]

Post a screenshot. Why can't you use imfreehand() if it's an image?