I am a student researcher and I am trying to develop a method using GIMP to quantify the average color of leaves through a RGB code. The only problem is, is when I try to get the sample average using color picker it wants to include the transparent. Is there a way around this? Or is there a way to block the transparent or alpha channel from the color picker? I want to include as much leaf area as possible which means that I do not want to be stuck scaling rectangles into a 600x600 px image then taking the sample average of that. Thank you for your help.