Re: Loading and average PGM files

[Carnë Draug]

On 18 June 2012 13:51, Laurent Hoeltgen <address@hidden> wrote:
> On 06/18/2012 02:17 PM, Jordi Gutiérrez Hermoso wrote:
>> On 18 June 2012 07:38, Mathieu <address@hidden> wrote:
>>
>>> My pgm files are depth images of 640 over 480 pixels. I already tried imread
>>> function typing: imread('1.pgm')
>>>
>>> and I get this error:
>>>
>>> error: imread: invalid image file: Magick++ exception: Magick: Invalid
>>> colormap
>>> index (index 65287 >= 256 colors,
>>> /home/mja/Documents/test/Following/d/1.pgm)
>>> reported by magick/colormap.c:239 (MagickConstrainColormapIndex)
>>> error: called from:
>>> error: /usr/share/octave/3.2.4/m/image/imread.m at line 74, column 7
>>>
>>> Any ideas on what's going wrong?
>>
>> It looks like you're using Ubuntu.
>>
>> Can you try with a newer Octave version?
>>
>>     
>> http://octave.org/wiki/index.php?title=Octave_for_GNU_Linux:_Binary_Octave_packages_for_GNU_Linux#Unofficial_binaries
>>
>> Also, can you show us a sample image on which you see this problem?
>>
>> - Jordi G. H.
>> _______________________________________________
>> Help-octave mailing list
>> address@hidden
>> https://mailman.cae.wisc.edu/listinfo/help-octave
>>
>
> Hi,
>
> tried it on ubuntu 11.10 with octave 3.6.1 and I get the following:
>
> warning: your version of GraphicsMagick limits images to 8 bits per pixel
> error: imread: invalid image file: Magick++ exception: Magick: Invalid
> colormap index (index 65287 >= 256 colors,
> /home/laurent/Downloads/1.pgm) reported by magick/colormap.c:239
> (MagickConstrainColormapIndex)
> error: called from:
> error:   /usr/local/share/octave/3.6.1/m/image/imread.m at line 74, column 7

The GraphicsMagick that Debian (and therefore Ubuntu sinde Ubuntu
ports from Debian) use are compiled with quantum depth 8 so you can't
use it to open images with more than 8bit per pixels. You'll have to
recompile GraphicsMagick with Q=16 or 32, and then compile Octave
again using that GraphicsMagick

 This is well know. You should ask the maintainers of the Debian and
Ubuntu packages to do this. Please let them know that you are also
interested on having this fixed at
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=557879

Carnë