After thinking on it I decided I should explain in more detail my
objection to flip/orientation specification in the raster in more
All printers should be able to consume (PWG) Raster but it more likely
that most mid and higher end printer will consume PDF. It is also more
likely that it will be lower end printers, those with limited resources,
which will directly consume (PWG) Raster. Since by definition they have
limited resources it would be burden to have these printers perform
flip/orientation transforms that require very large buffers that would
basically have to hold an entire page worth of raster data. (example; a
typical Epson inkjet can print width is US Legal and has a specified
maximum page length of 44 inches. Lets assume we are just talking 24
bit RGB data on legal size media at high quality print DPI of 1440v x
2880h or 8.5*2880*3x1440*13 or about 1.3 gb. Big and expensive. For
larger media size and if CMYK or CMYKLcLm data was sent to the printer
we are talking very large buffers. I am not sure if a printer has to
support all of color-spaces defined in the (PWG) Raster; but the largest
on is 30 byte per pixel!!! That really big and expensive.
In the old days, when there were printer drivers; they handled producing
raster content for the target printer in the orientation the printer
needed. In the new order of things, where there are no printer drivers;
it is up to the producer of the raster to put the content in a
"standard" format for printer and not to expect the printer to perform
additional transforms the raster content.
* Raster must continue to mean ready for the printer to consume.
* Raster must be targeted to specific printer or at least printer
model. If the print-job is re-targeted to a different printer then the
raster may have to be regenerated to the new target printer.
* The Alternate to the above is the raster producer will orient
and flip the print content exactly the same for all printers and based
solely on the user print intent. Then it is the print vendor issue to
consume this standardized format and ensure the correct output is
obtained. In this case, there is no need to put this information in the
raster header since it has no meaning or value to printer.
In conclusion, I would have not objection to the data being present in
the header only if something like the follow clause were added.
"The orientation or flip information is provided only as informational
data. The orientation or flip data SHALL NOT require the printer to
perform any transforms to the raster content to print the raster content
to meet the end-user's print intent."
From: Petrie, Glen
Sent: Tuesday, April 26, 2011 4:06 PM
To: ipp at pwg.org; 'Michael Sweet'
Cc: Petrie, Glen
Subject: PWG Raster comtinue
We still seem to differ on the adding page number and flip/orientation.
I hope we agree on adding the driver data fields to the PWG Raster.
An unusual request: I would like to understand better the need for
flip/orientation in a raster. Since I do not know who or what company
may have requested the flip/orientation data, would it be possible for
you to send an email to the individuals who requested the
flip/orientation asking if they can state why they need the data and why
they are not expecting the raster to be in the correct flip/orientation
that the printer would need to print the specified print job.
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