[IPP] PDF Raster and IPP Scan

[IPP] PDF Raster and IPP Scan

[IPP] PDF Raster and IPP Scan

Michael Sweet msweet at apple.com
Wed Sep 6 13:50:21 UTC 2017


Smith,

It is more of a receipt of the settings that were used for the scan - the PDF file is the result/output from the scan job.


> On Sep 5, 2017, at 5:57 PM, Kennedy, Smith (Wireless Architect) <smith.kennedy at hp.com> wrote:
> 
> Is the XML metadata addition being used as a replacement for what might be conveyed over IPP as IPP attributes (e.g. "job ticket" type info)?
> 
> 
>> On Sep 5, 2017, at 6:44 AM, Michael Sweet <msweet at apple.com> wrote:
>> 
>> Paul,
>> 
>> As this is a strict subset of PDF and IPP Scan requires PDF support, nothing needs to be added unless you want the Client to be able to explicitly ask for a particular subset of PDF...  We could add a pdf-versions-supported keyword, but that is strictly informative...
>> 
>> That said, this subset is almost exactly the same as the PDF/is specification the PWG published 13 years ago:
>> 
>>   http://ftp.pwg.org/pub/pwg/candidates/cs-ifxpdfis10-20040315-5102.3.pdf
>> 
>> The main differences appear to be:
>> 
>> 1. No JBIG2 support (?!?)
>> 2. Different file format identification methods: PDF/is adds a new object, while PDF Raster uses a comment in the trailer.
>> 3. PDF Raster supports encryption while PDF/is does not, but that doesn't really matter - PDF encryption is a joke because key generation is weak.
>> 4. PDF Raster adds an XML (Adobe XMP) metadata object.
>> 
>> Both PDF/is and PDF Raster support banding, digital signing, and incremental/streamed writing.  Both also support the same bi-level, grayscale, and RGB color color spaces and bit depths.
>> 
>> The PDF Raster spec claims that it can be consumed by a simple parser, but I don't see how given that images can be banded - you will still need to implement a minimal page stream interpreter along with random access to the image objects.
>> 
>> Finally, it looks like a PDF writer could generate a PDF file that conforms to BOTH PDF/is and PDF Raster - thus an IPP Scan implementation could (as part of the general PDF support requirement) produce PDF scan files compatible with both standards.  But again, I don't think we need to update IPP Scan for this...
>> 
>> 
>> 
>>> On Sep 1, 2017, at 8:34 AM, Paul Tykodi <ptykodi at tykodi.com> wrote:
>>> 
>>> Hi,
>>> 
>>> I saw this announcement this morning.
>>> 
>>> Should we consider adding support for this format in IPP Scan?
>>> 
>>> http://www.prweb.com/releases/2017/08/prweb14644230.htm
>>> 
>>> Best Regards,
>>> 
>>> /Paul
>>> 
>>> Sent from my iPhone
>>> _______________________________________________
>>> ipp mailing list
>>> ipp at pwg.org
>>> https://www.pwg.org/mailman/listinfo/ipp
>> 
>> _________________________________________________________
>> Michael Sweet, Senior Printing System Engineer
>> 
>> _______________________________________________
>> ipp mailing list
>> ipp at pwg.org
>> https://www.pwg.org/mailman/listinfo/ipp
> 

_________________________________________________________
Michael Sweet, Senior Printing System Engineer



More information about the ipp mailing list