From simon.urbanek at r-project.org  Wed Jul 31 16:17:39 2013
From: simon.urbanek at r-project.org (Simon Urbanek)
Date: Wed, 31 Jul 2013 10:17:39 -0400
Subject: [Rd] Adding text comments to graphics device output files?
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Message-ID: <D25A53EE-AAC2-42DA-8264-FD5E602DBB33@r-project.org>


On Jul 31, 2013, at 12:12 AM, Henrik Bengtsson wrote:

> Hi Duncan,
> 
> this is perfect timing.  Your
> https://github.com/duncantl/png/blob/master/testMeta.R example
> illustrates what I'm looking for.
> 
> Yes, it would be great if this would be incorporated into the 'png' package.
> 

Ok, I have added support for both text chunks and arbitrary R metadata to the PNG package.
http://rforge.net/png
The it is based on Duncan's idea, but the implementation and API is different -- Duncan's approach was implemented before png has support for the PNG info, so it is now simply extending that concept. You can store native text key/values pairs. In addition, R-native matadata can be attached -- it is stored as a special key "R.metadata" holding the serialization of the R object. See the last example in
http://rforge.net/doc/packages/png/writePNG.html
Feedback is welcome.

Cheers,
Simon



> Thanks,
> 
> Henrik
> 
> On Tue, Jul 30, 2013 at 8:04 PM, Duncan Temple Lang
> <dtemplelang at ucdavis.edu> wrote:
>> 
>> Hi Henrik
>> 
>> I have some extensions of Simon U's png package
>> to read and write metadata elements for PNG.
>> They are at
>>   https://github.com/duncantl/png.git
>> 
>> When I have time to completely test them, maybe Simon
>> may incorporate them.
>> 
>>  D.
>> 
>> On 7/30/13 7:59 PM, Henrik Bengtsson wrote:
>>> Hi,
>>> 
>>> several image file format supports textual/meta data comments in one
>>> way or the other.  For me an obvious usage would be to add
>>> sessionInfo() information to PNG and PDF image files, ideally from
>>> within R although external tools would work as well(*).  Has anyone
>>> looked into this or have any suggestions or comments?
>>> 
>>> /Henrik
>>> 
>>> (*) One could even imagine including self-contained R
>>> scripts/vignettes within such comments.
>>> 
>>> ______________________________________________
>>> R-devel at r-project.org mailing list
>>> https://stat.ethz.ch/mailman/listinfo/r-devel
>>> 
>> 
>> ______________________________________________
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> 
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> 
> 



[Rd] Adding text comments to graphics device output files?
Simon Urbanek