QTR-Quadtone RIP

Good, you get the idea.  One temp fix that I thought of was to make the default
ppi = 360 rather than the current 128.   This way I think you could
always out 360dpi
jpegs from LR print module and they would work.

Roy

On Tue, Jan 1, 2013 at 1:30 AM, stephane_bosman <stb@...> wrote:
> Thanks Roy. You are exactly on the problem I have.
>
> In the Lightroom print module, one can choose a custom size for the resulting jpeg. I use a size a bit smaller than the print area on the target paper size and tell QTRGui to print centered.
>
>
> Happy new year to all!
>
>
> --- In QuadtoneRIP@yahoogroups.com, Roy Harrington <roy@...> wrote:
>>
>> I've done some looking into this whole jpeg issue.  The whole thing is a bit
>> complicated but I think I understand some of it now.
>>
>> Originally there was a simple jpeg compression file that did not have
>> resolution information -- it just compressed the image data.  Soon after
>> a header called JFIF was added with some more info -- specifically
>> the resolution.  Most older programs used this for a long time.  More recently
>> a more general approach was started -- called EXIF data which most people
>> recognize from camera data.   The file extension .jpg and .jpeg are now used
>> for all these different formats.  So different programs write out
>> different headers
>> -- in fact Lightroom seems to use one for export and a different one for print.
>> (QTR is not the only program affected:  see
>> http://forums.adobe.com/message/2977973
>> if you want to see an unending discussion)
>>
>> QTR on the PC has two distinct parts the QTRgui which is written in a high level
>> language with file reading builtin and a low level part which actually
>> writes to the
>> printer.  So QTRgui understands some more formats than the low level driver.
>> The driver uses open source libraries for reading files and the jpeg
>> library does not
>> look at or understand the EXIF version of the header --only the JFIF version.
>> This is the main cause of the print size problems.  Whether this can be easily
>> resolved is still unknown.
>>
>> Another thing to consider is that in Lightroom the export and print
>> modules have
>> pretty different concepts in mind.  The export is pretty
>> straightforward -- it simply
>> exports just images -- conversions and formats are always one image at a time.
>> The print module on the other hand is a page formatting function.
>> When you print to
>> jpeg file you are formatting an entire page and outputting that full
>> page as a jpeg.
>> It can contain multiple images and most important includes all the borders and
>> margins.  So taking this formatted page and putting it into QTRgui which also
>> does page formatting is possible but needs careful thought of what's happening.
>> In particular LR formatting a 8.5x11 sheet will output an 8.5x11 jpg.
>> But reading
>> this into QTRgui for printing on 8.5x11 paper is a problem because of
>> the margins.
>> Typically the largest image is 8.25x10.75 on most Epson printers
>> (non-borderless).
>>
>> Needless to say there are a lot of considerations here.  I'll try to
>> find a workflow
>> that accommodates this.
>>
>> Thanks,
>> Roy
>>
>> BTW, there's a little confusion of terminology here.  QTRgui is a
>> program only on
>> the PC and Print-Tool is Mac only.  I think QTRgui is being mentioned on the Mac
>> but I think its really referring to the print dialog page.
>
>> Roy Harrington
>> roy@...
>> www.harrington.com
>>
>
>
>
>
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-- 
Roy Harrington
roy@...
www.harrington.com