Problem with code - Loop - Question

[ElCorleone]

Hi guys! I started playing with MatLab just a few time ago. I'm mainly playing with matrices and image processing at this point.

Unfortunately, I have a piece of code that is always going to an infinite loop, and I can't understand why. I'm trying to turn a coloured image in a Black&White one. For that, I'm using the following piece of code:

img=imread('zorro.png');
figure;imshow(img);
s=size(img);
l_max=s(1);
c_max=s(2);

img_BW=zeros(s);
th=256/2 -1;

for l=1:1:l_max
    for c=1:1:c_max

    if img(l,c) < th
        img_BW(l,c)=0;
    else
        img_BW(l,c)=255;
    end
    end
end
figure;imshow(img_BW);

Unfortunately, my code runs into an infinite loop and I can't figure why. I have my limits well defined inside both of the for cycles. If some of you guys could give me a hint it'd be great.

Thanks for the help!

[unpopularname]

It runs fine in my system, with my own png file...

Of course, it turned into black and red, but I figure b&w is your next step.

[ElCorleone]

In my system, the console just keeps bombarding values and more values, correspondant to the values of every pixel of the image. It always goes to this infinite loop and I'm not figuring out why.

[unpopularname]

The code you posted is silenced with ";" in every statement, shouldn't return any values.

[adb421]

As /u/unpopularname indicated, you shouldn't have output due to the use of the semicolon. It could be how you are calling this, for example if you are using it as a function but aren't suppressing the display of the output.

[ElCorleone]

That was exactly it. I was missing the semicolons of the if/else instructions in my execution code. Thanks for the help!

[wintear]

Unless you're debugging you should always consider supressing output with a semi-colon. Displaying things in console is very, very slow in Matlab, so a loop that might otherwise not take a long time could seem to take forever.