Is there a way or filter like fourier to remove area from image?

hi all,

Is there a way to remove area from this thermal image like attached image. I dont want to upper side dark red area in the image. Because it is unnecessary area that impair the image for image processing.

Answer 1

[Walter Roberson]

threshold the image on an appropriate channel. set the dark portions to 0.

Or when you say "remove" do you mean "crop" ?

[ali]

I want to this process before convert images grayscale and binary. Because these are suquential images and reading from file. So ı want to make this before image process options. It will be with crop or something else.

Then ı want to find error on image for example fo this picture there is a hole on it.