Printing options

[Kurt Pfeifle]

James Richard Tyrer wrote:

> Kurt Pfeifle wrote:
> 
>> James Richard Tyrer wrote:
>>
>>> I'm not exactly clear on this.  My PPD for my old line printer has:
>>>
>>> *DefaultResolution: 360dpi *Resolution 60dpi: "1 dict dup
>>> /HWResolution [60 60] put setpagedevice" *Resolution 180dpi: "1 dict
>>> dup /HWResolution [180 180] put setpagedevice" *Resolution 360dpi: "1
>>> dict dup /HWResolution [360 360] put setpagedevice"
>>>
>>> So, it has both a "DefaultResolution" and three "Resolution" settings
>>>
>>
>>
>> No it has only three "Resolution" settings, one of which is the default.
>>
> Sure looks like "DefaultResolution" to me. :-)
> 

Exactly.

>> If you select to "Configure Printer" in the web interface, you may be 
>> able to change it to a different default resolution. The default
>> resolution is used by the printer's PS interpreter
> 
> 
> What we are discussing here is what use the KDE application and/or the Qt
> PostScript driver is going to make of these.
> 
>> (which may be CUPS if it is a non PS printer) to apply if the
>> application-generated PS doesn't include another resolution
>> directive....
> 
> 
> CUPS may also read this information -- to choose the correct driver 
> settings 

You need to differentiate: CUPS parts acting as a PS interpreter (in its
role as a server) and CUPS as a "driver" (when acting as a client).

> -- but all the PS interpreter uses is the information which is 
> *in* the PS file. 

True -- if there is something *in* the file.

I was talking about the case that there is *nothing* about resolutions
in the file. Then the "cups" Ghostscript device or the "imagetoraster"
filter apply the default resolution found in the PPD assigned to the
target queue.

> Yes, I know that GhostScript accepts resolution on 
> the command line, but IIUC, that is passed to the GhostScript "Device" 
> (the driver).
> 

This is if you

>> Similar goes for other user-selectable options: various settings
>> possible, one of which is the default.
>>
> Yes, I know that, but was having trouble understanding exactly what Till 
> said.
> 
> So, the question remains, does the Qt PostScript driver use the 
> resolution to interpolate an image.  It appears not.
> 

I know quite some PS-generating applications which don't use the PPD
setting. They just dump/embed the image "as is" into the PS file and
don't rasterize or compute it. They *may* write a little resolution
directive for the final interpreter and tag it to that image.

Cheers,
Kurt