MATLAB: How to feature extract from an image with black background(without taking the black background in consideration)

backgroundfeaturesimage processingImage Processing Toolboxlesionroi

I was scrolling through some answers of the same issue and got the following
C = num2cell(YourImage);
C(~YourImage) = {{}};
This will give you a cell array in which there are empty cells ("nothing") where the background was, and cells containing [1] where the foreground was.And
imagesc(YourImage, 'AlphaData', YourImage)
colormap(gray)
set(gca, 'color', 'none')
to set the Region of interest visible,i did try it myself and didn't get a result,What am i doing wrong and the correct way to use this code.

Best Answer

Looks weird. Very, very weird. I'd say what you're doing wrong is using cells in the first place. I don't see any reason for that. Why put each pixel into a cell? And then make the cells empty where the image is zero? And it's not going to put a 1 in cells with foreground. It's going to have the original gray levels in the cells. I mean, you could simply do the same thing that you say you want (0=background of 0, and 1 = foreground of non-zero) much better and with far, far less memory usage simply by saying
C = (YourImage ~= 0).
Post your image and say what feature in it that you're trying to measure.
Related Question