MATLAB: Extracting a range of pixel values from a specific RGB band

Question

I am trying to extract all pixels that are in the range 128 – 256 of the green band on an RGB TIFF. I can create a mask, but when I try to get an image with just these pixels I end up with a binary image, but I want to see all the pixels within my range.

This is what I've done:

>> I = imread(fullfile('D:\MatLab_Practice', 'RGB.tif'));

>> green = I(:,:,2);

>> imhist(green)

>> mask = green > 127; %(I have also tried the roicolor(green,128,256) to create a mask with same results)

>> G1 = double(green);

>> G2 = G1 .* mask;

if I use imhist(G2) I don't see the values I want, but using histogram(G2) I see everything I don't want as zero and and the range of values I need. But when trying to view my image I still only get a binary black and white image.

Any advice on how to proceed?

Answer 1

NEVERMIND figured it out!

need to convert mask to integer and then multiply by the original green band

>> I = imread(fullfile('D:\MatLab_Practice', 'RGB.tif'));

>> green = I(:,:,2);

>> imhist(green)

>> mask = green > 127; %(I have also tried the roicolor(green,128,256) to create a mask with same results)

>> mask = uint8(mask); %to match the same data type as image

>> G2 = green .* mask;