Question

I am new in MATLAB, I am trying to implement flood filling using this algorithm in matlab, I dont know what I did wrong may be I didnt used recursive function right, but still I dont whats going wrong and this code make my matlab close
I am using the following code I am trying to debug it since morning but failed to find the problem

function [ colored_Image ] = floodFill( image, target_Loc_x, target_Loc_y, targetColor, replacementColor )
colored_Image = image;

if (target_Loc_x >= 1) && (target_Loc_x <= size(image,1)) && (target_Loc_y >= 1) && (target_Loc_y <= size(image,2))
    if image(target_Loc_x,target_Loc_y) == targetColor
        colored_Image(target_Loc_x,target_Loc_y) = replacementColor;
        colored_Image = floodFill(colored_Image,target_Loc_x ,target_Loc_y + 1, targetColor, replacementColor); 
        colored_Image = floodFill(colored_Image,target_Loc_x + 1,target_Loc_y, targetColor, replacementColor);
        colored_Image = floodFill(colored_Image,target_Loc_x,target_Loc_y - 1, targetColor, replacementColor);
        colored_Image = floodFill(colored_Image,target_Loc_x - 1,target_Loc_y, targetColor, replacementColor);
    end

end


end

calling this function using

image = floodFill(im,1,1,0,127);
imshow(image);

im is my matrix image of 200 by 200 I want my black color(0) to grey color(127), any help will be thankful

Answer 1

You are probably hitting Matlab’s recursion limit. My computer doesn’t crash, but generates this error:

Maximum recursion limit of 500 reached. Use set(0,’RecursionLimit’,N)
to change the limit. Be aware that exceeding your available stack
space can crash MATLAB and/or your computer.

The way around this is to rewrite floodFill so it does not use recursion. There are some alternative algorithms on Wikipedia.

Also: aardvarkk’s answer makes an important point about Matlab’s column-major indexing. You can fix your function by swapping all x and y variables.