I have an image of bone on an implant. I would like to get the percentage of the implant covered by bone. I have written code for collecting pixels with a value less than 250 and pixels greater than 250 and dividing them, but the background is all white. How can I crop the image to get rid of the background or is there a more efficient/exact way to get this value? The photo is like the one attached but with a white background and taken from straight above. Thank you!