[Wylug-help] Set PDF background to transparent without quality loss

[Gary Stainburn]

I've looked at LaTeX before and found the first step a big one - too big for 
my purposes.  I create a new PS file once maybe every 5 years :-)

On Tuesday 22 September 2015 12:35:47 Dan Walker wrote:
> If you get the logo/background stuff as a PS file, you could do worse
> than use LaTeX to do the extra text.
>
> Such lovely typesetting ;)
>
> Dan
>
> On 22/09/15 12:27, Andrew 'Leny' Lindley wrote:
> > Sorry Gary,  I'm so used to your average custom software
> > 'advanced/expert' programmer either refusing or making obvious lie
> > excuses so as not to do what you are going to that I didn't suggest
> > it.  :)  Nice to be in the land of the living again. :)
> >
> > Leny
> >
> > On Tue, 2015-09-22 at 10:14 +0100, Gary Stainburn wrote:
> >> I have decided that the easiest way to do this is use a technique I have
> >> used before for creating computer generated delivery notes etc.
> >>
> >> I will create a new PS file with the images emedded as EPS images. That
> >> way, not only will I have total control over the layout etc. but
> >> hopefully I will end up with a smaller PDF file once I do the ps2pdf.
> >>
> >> Many years ago I wanted to be able to create PDF files from PHP for both
> >> printing and emailing.
> >>
> >> By hand writing the PS files, and embedding tokens, for the text fields,
> >> simple preg_replace statements populate the form before converting to
> >> PDF.
> >>
> >> I don't know why I didn't just do that in the first place.
> >>
> >> Gary
> >>
> >> On Monday 21 September 2015 18:56:09 Andrew 'Leny' Lindley wrote:
> >>> FWIW ISTR early FLOSS PDF implementations had problems cos the native
> >>> image format was some flavour/revision of TIFF which is Adobe owned[1].
> >>> Also PDF is based on a subset of Postscript[2].  You might, therefore,
> >>> try things like converting your background to TIFF or EPS before
> >>> merging it.  But note, transparency - which seems to be what you're
> >>> after, is a PDF property not in PS[ibid].  So you might try producing
> >>> your background as a PDF with image transparency in something like
> >>> Scribus (FLOSS DTP).
> >>>
> >>> Just ideas,
> >>>
> >>> Leny
> >>>
> >>>
> >>> [1] https://en.wikipedia.org/wiki/Tagged_Image_File_Format
> >>> [2] https://en.wikipedia.org/wiki/Portable_Document_Format#PostScript
> >>>
> >>> On Mon, 2015-09-21 at 10:36 +0100, Gary Stainburn wrote:
> >>>> Thanks Dan,
> >>>>
> >>>> I'm installing inkscape as I'm typing this, and will have a look.
> >>>>
> >>>> I'm also trying to get hold of the original art work.
> >>>>
> >>>> This list has been quiet for a long time, but it's good to see that
> >>>> the meetings are starting up again.
> >>>>
> >>>> Pity it's not convenient for me any more, or I'd bob down.
> >>>>
> >>>> Gary
> >>>>
> >>>> On Monday 21 September 2015 10:15:26 Dan Walker wrote:
> >>>>> Hmm.
> >>>>>
> >>>>> Editing scanned bitmaps might well reduce quality - you won't get
> >>>>> decent-looking lines if the scan goes through a .JPG stage.
> >>>>>
> >>>>> Ideally, you'd get / recreate the invoice paper in a vector package -
> >>>>> You could try asking whoever created it in the first place, or maybe
> >>>>> try converting your scan to vector with Inkscape, then output it as a
> >>>>> PDF after clean-up?
> >>>>>
> >>>>> Failing that—and cleaning up vectors traced from a bitmap can be
> >>>>> tiresome—you could try setting your scanner to produce non-compressed
> >>>>> (or lossless) images such and PNG or GIF, and then convert the white
> >>>>> to transparent with Imagemagick (e.g. see
> >>>>> http://www.imagemagick.org/discourse-server/viewtopic.php?t=12619 - I
> >>>>> haven't tried it though )
> >>>>>
> >>>>> There's no ideal solution from a scanned image, scanned bitmaps are
> >>>>> hard to make look "clean" when they're actually artwork rather than
> >>>>> photographs.
> >>>>>
> >>>>> Yrs,
> >>>>>
> >>>>> Dan
> >>>>>
> >>>>> (Gosh, it's been a while since I posted here ;)
> >>>>>
> >>>>> On 18/09/15 12:47, Gary Stainburn wrote:
> >>>>>> Hi all,
> >>>>>>
> >>>>>> As part of my virtual Printer -> invoice paper -> PDF project I'm
> >>>>>> struggling.
> >>>>>>
> >>>>>> I've got everything working except merging the invoice paper and the
> >>>>>> invoice.
> >>>>>>
> >>>>>> I have a single page PDF with the invoice stationery from a scanned
> >>>>>> original. I have the invoice as produced by our business management
> >>>>>> software
> >>>>>>
> >>>>>> I then ran
> >>>>>>
> >>>>>> pdftk invoice.pdf background  invoice_paper.pdf output output.pdf.
> >>>>>>
> >>>>>> Unfortunately this didn't work because our business software
> >>>>>> splatted all over the company logo.
> >>>>>>
> >>>>>> I then tried
> >>>>>>
> >>>>>> pdftk invoice.pdf background  invoice_paper.pdf output output.pdf.
> >>>>>>
> >>>>>> which priority to the invoice paper, effectively putting it over the
> >>>>>> invoice instead of behind it.  This of course means that the blank
> >>>>>> background of the paper splats over the invoice.
> >>>>>>
> >>>>>> The answer is to make the white background of the invoice_paper.pdf
> >>>>>> transparent.  I've tried doing this using PDFedit, convert, and gimp
> >>>>>> but the end result is a significant reduction of the quality of the
> >>>>>> invoice_paper.pdf.
> >>>>>>
> >>>>>> Can anyone suggest al alternative method, preferrably also removing
> >>>>>> the blemishes on the scanned paper.
>
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-- 
Gary Stainburn
Group I.T. Manager
Ringways Garages
http://www.ringways.co.uk