How can I select a part of an image in C#?

Question

Lets say I have a picturebox and I want to crop the image. I know how to crop by rectangles. I want to be able to select a part of the image with mouse and crop it. I think its called Free Form Selecting.

Answer 1

It really is simply tracking one corner of your selection rectangle (usually captured with the MouseDown event) and also the opposing corner for your selection rectangle (usually captured with the MouseUp event). These two coordinate pairs give you the region that the user selected.