IPP> First draft IPP standard for Color and Imaging Attributes availab le

IPP> First draft IPP standard for Color and Imaging Attributes availab le

IPP> First draft IPP standard for Color and Imaging Attributes availab le

Michael Sweet mike at easysw.com
Wed Oct 23 10:55:31 EDT 2002


Hastings, Tom N wrote:
 > I've down loaded a first draft for an IEEE-ISTO IPP Color and Imaging
 > Attributes standard to the PWG FTP site.  Most of the attributes
 > control color and imaging that is prevalent in the industry following
 > industry standards.  The files are available at:
 >
 > ftp://ftp.pwg.org/pub/pwg/ipp/new_COLOR/pwg5100.8-D01-021018.pdf
 > ftp://ftp.pwg.org/pub/pwg/ipp/new_COLOR/pwg5100.8-D01-021018.doc

OK, I've only had a chance to skim this draft, but some thoughts:

     1. There is no "adjust-hue (integer(-180:180))" attribute;
        this is something that CUPS has provided since day one,
        and it has some interesting (and sometimes even practical :)
        applications when printing images.

     2. There are no "image-subsampling" attributes, only the
        "anti-aliasing" attributes.  Most images are subsampled
        when printed (since the printer resolution is typically
        != the image resolution), and it can be important to
        specify the default subsampling in documents.  I would
        suggest the following pre-defined keyword values:

            "none"   = nearest-neighbor sampling
            "linear" = linear interpolation
            "cubic"  = cubic interpolation

        Other algorithms are also possible (some include sharpening
        effects, etc.), but these three cover the common algorithms.

     3. The current conformance requirements are pretty vague.
        It might be useful to summarize the basic conformance
        requirements of each group of attributes in section 6,
        or at the begining of each group, so that implementers
        can know immediately which attributes are REQUIRED and
        which are OPTIONAL.  At the same time, this will allow
        clients to determine quickly if the destination device
        supports the group of attributes it needs.

        (I guess I'm saying we need to define that some groups
        of attributes are connected, and if you implement one
        you have to implement them all for consistency)

-- 
______________________________________________________________________
Michael Sweet, Easy Software Products                  mike at easysw.com
Printing Software for UNIX                       http://www.easysw.com




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