[LON-CAPA-admin] ImageMagic conversion of some png files fails.... is there a an upgrade needed?

[Stuart Raeburn]

Hi,

> I haven't checked this out on Centos 6 yet, but part of the inherent  
>  problem as I saw it
> was that Centos 5 has an older version of ImageMagick which does not  
>  do the png conversion.

ImageMagick's command:
convert <imagefile.png> <imagefile.png.eps>

which is used to convert a png file to an eps file for incorporation  
in the PDF generated by LON-CAPA's print utility reports a  
segmentation fault for ImageMagick-6.2 and older, if imagefile.png is  
an 8-bit alpha channel png.

By contrast there is no segmentation fault, and the image is rendered  
correctly in the PDF when using ImageMagick-6.3 and later.

The following Linux distros have a version of ImageMagick that  
predates 6.3, and therefore do not currently support conversion of  
8-bit alpha channel png files:

RHEL 4, CentOS/RHEL/Scientific Linux 5, SLES9 and 10.

Accordingly, ImageMagick and ImageMagick-perl 6.3 rpms will be built  
and added to the "custom" LON-CAPA repos at install.loncapa.org for  
these distros/versions.

All other Linux distros for which LON-CAPA is supported:
RHEL/CentOS/Scientific Linux 6; Ubuntu LTS 8.04 - 12.04, SuSE 11.1 -  
12.3, Fedora 9-19 already have ImageMagick 6.3 or newer in their  
standard repos, so are not affected.


See bug 6652 for details.
http://bugs.loncapa.org/show_bug.cgi?id=6652#c9


Stuart Raeburn
LON-CAPA Academic Consortium.



Quoting Mark Lucas <lucasm at ohio.edu>:

> Ray,
>
> I haven't checked this out on Centos 6 yet, but part of the inherent  
>  problem as I saw it
> was that Centos 5 has an older version of ImageMagick which does not  
>  do the png conversion.
>
> Mark
>
> On Jul 28, 2013, at 8:19 PM, Raymond Batchelor wrote:
>
>> I posted a bug about this a while back, but I am encountering the   
>> issue more & more now.
>> I am wondering if there is a LON-CAPA fix needed or perhaps an   
>> update of ImageMagik package?
>>
>> Thought I'd draw attention to it now.
>>
>> Bug #6652
>>
>> "It appears that png files with alpha cannot be converted to the   
>> printout pdf.
>> Not sure where or why. One gets the message e.g.
>>
>> "An error occured during the conversion of
>> /priv/batchelo/2013tests/users_list_help/images/parallelogramrs.png.
>> If possible try to save this image using different settings and   
>> republish it."
>>
>> Is there a fix or should we just work around this by changing to opaque or
>> single bit tranparency gif?".... or what?
>>
>> Cheers,
>> Ray
>>
>>
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>
> --
> Mark Lucas 								email: lucasm at ohiou.edu
> 252D Clippinger Lab						phone: (740)597-2984
> Department of Physics and Astronomy		fax: (740)593-0433
> Ohio University
> Athens, OH 45701
>
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