[MFD] Question on Resolution Versus Qaulity

[MFD] Question on Resolution Versus Qaulity

larryupthegrove larryupthegrove at comcast.net
Thu Feb 2 00:00:56 UTC 2012


Glen,

 

There are several print devices where quality settings are resolution
independent - fuser temperature, speed at which paper is transported, etc.

 

If I specify a line or pattern in a raster format, I may need to specify the
resolution so that the printed output matches the intent, such as 300 dots
equals 1 inch.

Especially important in barcodes, drawing objects, etc.

 

Larry

 

From: mfd-bounces at pwg.org [mailto:mfd-bounces at pwg.org] On Behalf Of Petrie,
Glen
Sent: Wednesday, February 01, 2012 3:45 PM
To: Michael Sweet
Cc: mfd at pwg.org
Subject: RE: [MFD] Question on Resolution Versus Qaulity

 

Conceptually there is no reason a printer could not support a draft mode for
multiple resolutions (and this is in fact the case in CUPS/Mac OS X), so
preventing both from being specified will do a disservice to the user and
printer/driver.

 

[gwp] So if we have "draft" at 75, 150, 300; and the user can select both
"draft" and 300; then what is the value of "draft" to the Print Service
since the Print Service was told to print at 300 dpi.

 

[gwp] Users are more likely to select "quality" equals "draft" and
"contentOptimize" equals "photo" and not a dpi (ops: resolution).   If a
user 'really understands' the Print Service performance for differing dpi's
(again ops: resolution's); then "quality" should never win because the user
knows exactly what dpi they want!

 

Quality != Resolution.  They may be related, and there may in fact be
constraints that cause a particular combination to conflict, but they are
not mutually exclusive and express separate intent.  The IPP/2.0
recommendation to prefer Quality over Resolution when there is a conflict is
a pragmatic approach to automatic conflict resolution.

 

[gwp] Print-Resolution is a function of both Quality AND Content-Optimize.
Any printer today can determine a resolution from these two values.  If a
user specifies a resolution then the Print Service should use the resolution
(resolution is always the winner) since the user is stating they want the
specified resolution that gives them a desired quality for the content!

 

[gwp] The conclusion is then

1.	Specified Resolution wins over "Quality"  - always, since the User
specified 'use this resolution".
2.	Content-Optimize MUST be required - for a printer to properly
determine the correct resolution when resolution is not specified.
3.	Print-Quality  is [Quality (-Intent) + Content-Optimize ] or [
Resolution] but not both.

 

Glen

 

 

 

 

 

On Feb 1, 2012, at 3:02 PM, Petrie, Glen wrote:

 

Mike, Pete, (All)

 

So, should the PJT not specify both but rather specify one or the other?  I
know that for the PJT, that "quality" is required while "resolution" is
optional.   So if "quality" is required and always wins; what is the value
or need for "resolution"?   The spec's do not have a value of "unknown" or
"other" for "quality"; so, the Print Service will not ever use the
"resolution" information and, in fact, the "resolution" data simply adds
confusion.  

 

However, if "quality" and "resolution" were made either-or-but-not-both,
then a client could specify either without a "winner".   The other option is
add the values "unknown" or "other" to "quality" which directs the Print
Service to use "resolution".

 

Glen

 

 

  _____  

From: Michael Sweet [mailto:msweet at apple.com] 
Sent: Wednesday, February 01, 2012 12:52 PM
To: Petrie, Glen
Cc: mfd at pwg.org
Subject: Re: [MFD] Question on Resolution Versus Qaulity

 

Glen,

 

This is covered in IPP/2.0; basically if there is a conflict between
resolution and quality, quality wins.

 

As far as PWG Raster goes, that is a separate capability
(PwgRasterDocumentResolutionSupported) that expresses the capabilities of
the input side of the printer's imaging engine, while Resolution expresses
the capabilities of the output side of the printer's imaging engine.

 

(i.e. a printer might only accept 360dpi raster data but print it at
2880dpi...)

 

 

On Feb 1, 2012, at 8:52 AM, Petrie, Glen wrote:





Pete (All),

 

I remember a discussion about resolution versus quality (I think the PWG
raster discussions).   I thought that is quality and resolution did not
agree (as interpreted by the print service capability/definition) then
quality was to be used.   In the PJT should resolution and quality be
denoted as either but not both?  Or at least should a note be added?

 

Glen

 


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_________________________________________________________
Michael Sweet, Senior Printing System Engineer, PWG Chair

 

 

_________________________________________________________
Michael Sweet, Senior Printing System Engineer, PWG Chair

 


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