Re: Octave 3.4.3 for Mingw; IMRead

[Juergen Rose]

Am Freitag, den 09.12.2011, 11:53 -0800 schrieb nitnit:
> I could imread this file simply by
> 
> I=imread('test7+Helio+Felt+1.jpg');
> 
> I couldn't imshow the full image (octave crashes probably because of memory
> problems for this 1500 by 10200 pixels image) but I could imshow portions of
> the pictures such as
> 
> imshow(I(1:500,:))
> imshow(I(501:1000,:))
> imshow(I(1001:1500,:))
> 
> and I could verify that the image has been read correctly.
> 
> I am running octave-3.4.3 on win7-x64 with 4Gbytes of memory.
> 
> So I can not reproduce the problem that you are facing on my system.


If I try to read the image I get a warning:

address@hidden:/home_moose/rose(9)$ octave
GNU Octave, version 3.4.3
Copyright (C) 2011 John W. Eaton and others.
...
Octave was configured for "x86_64-pc-linux-gnu".
...
octave:1> I=imread('test7+Helio+Felt+1.jpg');
warning: your version of GraphicsMagick limits images to 16 bits per
pixel
octave:2> imshow(I);

imshow() works without problems, but what means this 16 bits warning.
graphicsmagick was installed from sources under gentoo with the q16 and
q32 USE flags, which I interpreted as supportion of 16 bit and 32 bit
quantum storage size. If I install graphicsmagick without the q16 flag:

address@hidden:/root(7)# emerge -pvD graphicsmagick

These are the packages that would be merged, in order:
Calculating dependencies... done!
[ebuild   R    ] media-gfx/graphicsmagick-1.3.12-r1  USE="X bzip2 cxx
doc fpx jbig jpeg jpeg2k lcms modules openmp perl png q32 svg threads
tiff truetype wmf zlib -debug -imagemagick -q16" 0 kB

imread and imshow fails with:

octave:1> I=imread('test7+Helio+Felt+1.jpg');
warning: your version of GraphicsMagick limits images to 16 bits per
pixel
error: imread: invalid image file: Magick++ exception: Magick: Unable to
open file (t+1.jpg) reported by coders/jpeg.c:955 (ReadJPEGImage)
error: called from:
error:   /usr/share/octave/3.4.3/m/image/imread.m at line 74, column 7
octave:1> imshow(I);
warning: imshow: only showing real part of complex image

multiplot> plot "-" binary array=2x2 scan=yx origin=(1,1) dx=0 dy=0
using 1 title "" with image; ;
                    octave:2>                                         ^
           line 0: Sample period must be positive. Try `flip` for
changing direction


Any hint is appreciated.