Trying to cut an image via Matlab

Question

Dear friends I'm trying binarise the image, it’ll look best if I cut the black parts out. To avoid any funny edge effects I’ll crop the pattern to a circle, and so our ‘mask’ is drawn below, along with the relevant snippet of Matlab

P = imread('Pattern.png');
P = 1-im2bw(P); % Keep black parts
Nmin = min(size(P));
% Crop into square, then circle
P = P(1:Nmin, 1:Nmin);
[xg, yg] = meshgrid(1:Nmin, 1:Nmin);
P((xg - Nmin/2).^2 + (yg - Nmin/2).^2 &gt; 0.99*0.25*Nmin^2) = 0;
% Create a small border
P = padarray(P, [1 1], 0);

But for some reason I'm having issues with line 7,

Error: File: Try1.m Line: 7 Column: 42
Unbalanced or unexpected parenthesis or bracket.

please help me...

edit:

here is explanation

Define "issues". What are you attempting to do in line 7? What do you mean by "cut the black parts out"? Do you have sample input and output images? Your code doesn't actually have `>` in it, does it? — beaker, Jan 31 '17 at 19:28
Attach your image to the Q. Line 7 including the comments or excluding? — NKN, Jan 31 '17 at 19:32
@beaker added simple image to explain it, what do you mean by "youre code dosent actually have &gt"? — secret, Jan 31 '17 at 20:26

score 3 · Accepted Answer · edited May 23 '17 at 11:53

I assume that you have copied this code from a website. The reason is the following line:

P((xg - Nmin/2).^2 + (yg - Nmin/2).^2 &gt; 0.99*0.25*Nmin^2) = 0;

Notice the >? (which is what @beaker mentioned in their comment) If you check the original code on the website where you found it, there is probably a > instead of > right?

The reason is that in HTML, the > sign is displayed by writing > in the HTML source code. When the website is shown in your browser, it will convert > to the > sign, but apparently when copy-pasting the code, it apparently copied the HTML source code and not the rendered sign.

MATLAB of course can't handle HTML source code, so you have to replace > by > and your code works fine:

P((xg - Nmin/2).^2 + (yg - Nmin/2).^2 > 0.99*0.25*Nmin^2) = 0;

Trying to cut an image via Matlab

1 Answers1