[IPP] Requested Additions to PWG Raster

[IPP] Requested Additions to PWG Raster

[IPP] Requested Additions to PWG Raster

Michael Sweet msweet at apple.com
Fri Apr 22 17:19:45 UTC 2011

On Apr 22, 2011, at 9:34 AM, Petrie, Glen wrote:
> ... 
> [gwp] The important case is the size of the compressed raster data. The decompressed size is recorded only if the raster is uncompressed.
> [gwp] I agree that some (a few or a lot) of implementation may not provide the information but as I said, I am requesting that the assignment be made and those who can (want to) may record the size information.

It really isn't a matter of "may not provide", in most cases clients (and printers) simply can't buffer hundreds of megabytes of raster data. I can add the field, but since most producers of PWG Raster will not be able to supply the compressed size of the raster no printer will be able to depend on it anyways, so IMHO it is best to have the printer, if it is going to do any local processing of full page images, use its own optimal internal storage format than try to gerry-rig something into the format that just won't work.

> ... 
> I would actually prefer to flag the file as version 3 which is an uncompressed CUPS Raster with the version 2 page header. And in the case of local processing, you'll likely want to use native word order (another feature of CUPS Raster that we are not bringing along for PWG Raster...)
> [gwp] Do you mean big/little-endian?  I am nothing requesting the word ordering flag (value) be used.  The current specification is ok.

My main point was that if you are concerned about having a standard representation for intermediate data, CUPS Raster already provides that. If you are trying to tweak PWG Raster for use as an internal representation format then I'd rather not put that in the standard since internal formats are OOS for any PWG standard.

> Would it be sufficient to document an uncompressed version of PWG Raster (with the "RAS3" file header) and then mark the native word order support as out-of-scope for the spec but something that might be used internally?
> [gwp] I believe the RAS3 is for the entire PWG Raster file.  I am requesting a flags (value) for individual pages.  

Since the format does not support this, I would be opposed to adding something that would be used only for an internal representation of a PWG Raster file.

Michael Sweet, Senior Printing System Engineer, PWG Chair

This message has been scanned for viruses and
dangerous content by MailScanner, and is
believed to be clean.

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.pwg.org/pipermail/ipp/attachments/20110422/42ff8835/attachment-0001.html>

More information about the ipp mailing list