image processing matlab codes error

I'm really need help. I want to know what error at bwconncomp line. I had tried in other codes also but with the same mistake-mistake at bwconncomp line.

This is the codes for reference:

a = imread('image1_118.jpg');

binmap = uint8([0 180 200 255]); 
[counts, binidx] = histc(a(:), [0 111 151 256]); 
b = reshape( binmap(binidx), size(a) );

subplot(221);figure(1);imshow(b);

y=bwlabel(b); 
x=uint8(y); 
C = bwconncomp(x); 
CC = labelmatrix(C);

subplot(222);figure(1);imshow(y); 
subplot(223);figure(1);imshow(C);
subplot(224);figure(1);imshow(CC);

Thanks in advance.

[Walter Roberson]

What error message shows up for you ?

[Syahrul Niezam]

The error shows in line C = bwconncomp(x);

It is stated that:

Undefined function or method 'bwconncomp' for input arguments of type 'uint8'.

Answer 1

[Walter Roberson]

Which MATLAB release are you using? bwconncomp() is a newer routine, only a few releases old. You might need to use bwlabel() instead if that is what your release has.

Answer 2

[Image Analyst]

Like it says, bwconncomp() does not use grayscale images. It needs a binary image - this is of class "logical" not "uint8".

[Walter Roberson]

http://www.mathworks.com/help/toolbox/images/ref/bwconncomp.html

"BW can be a logical or numeric array of any dimension, and it must be real and nonsparse."

The first example shows an input matrix that is double precision.

I do not have a sufficiently new MATLAB to check the details myself, so I would get exactly the error message that is being reported.

[Image Analyst]

OK you're right - I just read the first line where it said it wanted a binary image. So in that case, I don't know why bwconncomp would say that, unless it's the old problem of having his own m-file of that same name, which I doubt, or if unless he's not passing a binary image (which is probable). I still have a question in to his duplicate question asking what labelmatrix() is.

Answer 3

[Image Analyst]

Are you sure "b" is really binary. Do this:

max(b(:))
min(b(:))

and tell us what it says. It should say 1 and 0.