ImageJ: enhance brightness/contrast of a selected region

Question

How do I enhance the contrast/brightness of only my selected region and not the entire image. I am trying to use freehand selection tool, but unsure how to proceed afterwards.

Thanks in advance,

KL

Answer 1

If you click the Apply button of the Brightness & Contrast dialog, it will alter the pixel values of the selected region (and only the selected region) to match the current Brightness & Contrast settings. This will achieve your desired effect, if what you want is to visualize that region at a different B&C.

Beware of performing any image analysis after that point though, since the raw pixel values will differ and you will then be comparing apples to oranges.

Answer 2

If you change the image type to RGB and then it will only change the contrast/brightness of the selection. (After changing the contrast you can change it back to 16bit)