Hi Mona,
Given you have a selected a ROI in a picture and would want to replace each pixel inside the area of mask with the average color, you can follow a simpler approach without using the "accumarray" function.Please refer to a demo example as follows:
% Making a test image with a circular ROI %
% -------------------------------------------- %
% Form a random test image of dimensions 100X100X3
image = zeros(100, 100, 3);
image(1:50, :, 1) = 0.8;
image(51:end, :, 2) = 0.8;
image(:, 51:end, 3) = 0.5;
% Making a circular ROI
[X, Y] = meshgrid(1:100, 1:100);
center = [50, 50];
radius = 25;
mask = (X - center(1)).^2 + (Y - center(2)).^2 <= radius^2;
% --------------------------------------------- %
% Initialize the result image
result = image;
% Loop through each color channel
for i = 1:3
channel = image(:,:,i);
% Calculate the average color within the mask
averageColor = mean(channel(mask));
% Replace the pixels in the mask with the average color
channel(mask) = averageColor;
% Allot the updated pixels in the result image in the respective color channel
result(:,:,i) = channel;
end
figure;
subplot(1,3,1);
imshow(image);
title('Original Image');
subplot(1,3,2);
imshow(mask);
title('Masked Image');
subplot(1,3,3);
imshow(result);
title('Image with Average Color')
Hope this helps
