is it possible to create a sub DIBs FROM A GIVENN LARGE DIB TAKING TOP ,LEFT,WI

its possible. I only work with raw rgb arrays however, the bitmap and dib and whatnot tools are aggravating.

Anyway, you should be able to go to the raw rgb data, grab what you want of it, and pop that into a new dib struct/class and fill in the header with the new size (copy all the other junk from the old header ) to create your sub image.