Re: type handling bug?

[John W. Eaton]

On 26-May-2009, Levente Torok wrote:

| > > im =imread("p1020037.jpg" );
| > > octave:10> sum(sum(im==0))
| > > ans = 16980
| > > 
| > > 
| > > 
| > > z=resize( im, s=rows(im)*columns(im),1 );
| > > octave:11> sum(sum(z==0))
| > > ans = 3144192
| > 
| > My guess is that you image is an RGB image (all JPEG's are RGB, right?).
| > This makes the image NxMx3, but you're treating it as being MxN. But I'm
| > just guessing here.
|  Wrong.
| 
| octave:17> size(im)
| ans =
| 
|    1536   2048
| 
| Instead of 
| octave:18> size(im)
| ans =
| 
|    1536   2048      3
| 
| Other ideas?

Yes.  As mentioned earlier, resize is probably not the function you
are looking for because it changes the size without preserving the
data.  Use "reshape (im, numel (im), 1)" or "im(:)" to convert your
array to a column vector.  The "im(:)" syntax is the normal way to do
this and should be faster than calling reshape.

jwe