Hi,
The provided function does not preserve the color information because the function currently processes only one dimension of the image. Images in MATLAB are 3D matrices, with the third dimension representing color channels (Red, Green, Blue).
Here is a modified function which preserves the color:
function NN = myResizeNN(picture, scale)
I = imread(picture);
[a, b, ~] = size(I);
IR = round([1:(b*scale)]./scale);
IC = round([1:(a*scale)]./scale);
output = zeros(length(IC), length(IR), 3, 'like', I);
for channel = 1:3
temp = I(:,:,channel);
output_temp = temp(:,IR);
output(:,:,channel) = output_temp(IC,:);
end
figure(1); imshow(I); title('Before interpolation');
figure(2); imshow(output); title('After interpolation');
NN = [IR,IC];
end
I hope this helps!