Combine pixels into regions

Hello everyone! There is such a task.

There is an image in which, after processing, the background has brightness = 0, objects have non-zero brightness. It need to combine these objects on the region and assign them an ID. The idea is this: the algorithm scans the image line by line, if it detects a non-zero pixel, stores its coordinates and the intensity(brightness) and starts checking neighboring pixels. If it detects non-zero ones among the neighbors, then it also stores their coordinates and intensity. Later these values ​​will be needed for calculations. When the first region is selected in this way, intensity = 0 should be assigned to all pixels included in it. After that, the algorithm continues to scan the image line by line in search of non-zero pixels and, if found, repeats the above steps. So far, I have it:

img = imread('t.png');
[x, y] = size(img);
 
for i = 1:x
    for j = 1:y
        if img(i,j) ~= 0       
            %store coordinates and brightness
            if img(i, j+1) ~= 0%%check right neighbor pixel  
                % store coordinates and brightness
                j = j + 1;
            end  
            if img(i+1, j) ~= 0%%check lower neighbor pixel  
                % store coordinates and brightness
                i = i + 1;                
            end
        end
    end
end

Answer 1

[Image Analyst]

Is this homework, where they asked you to write your own version of bwlabel() or bwconncomp? Otherwise, why not simply use one of those functions?

[Valeriya Gmyria]

okay, thank you! already figured with bwlabel.

[Image Analyst]

You're welcom, but what does that mean? Are you saying you just used bwlabel (like I suggested) instead of trying to rewrite it yourself? If so, can you please "Accept this answer"?

[Valeriya Gmyria]

I'm used bwlabel.