how do i select only a certain area of an image and then use it to get the mean pixel value?
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How can i select only the central red area of the star and then get the mean pixel value of the red channel?
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KALYAN ACHARJYA
on 7 Mar 2021
Edited: KALYAN ACHARJYA
on 7 Mar 2021
This is all about how you can correctly segregate ROI, what the red fields refer to, as there is no clear boundary in the area of interest items, the easiest way-
red_channel=rgbImage(:,:,1);
bwimage=imbinarize(rgbImage(:,:,1),0.3);
% Get the largest blob only
bwimage=bwareafilt(bwimage,1);
% Get data for mean
sum_pix=sum(bwimage(:));
mask=uint8(cat(3,bwimage,bwimage,bwimage)); % Just for display purpose
% Mask operation on Red Channel
red_seg=red_channel(bwimage);
fprintf('The Mean is: %f',sum(red_seg)/sum_pix);
imshow([rgbImage,mask.*rgbImage;])
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