manually draw shapes (like using a pencil to draw on figure) on opened image

Hi! I want to manually draw lines/curves/shapes on an opened image figure, just like using the pencil tool in the paint program of windows, and let the program record the pixels that I have drawn into a variable. Is there an existing function to do this? Thanks in advance.

Answer 1

[Shoaibur Rahman]

Try:

roipoly

[Quan]

Thanks! very helpful function.