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

[Gary Stainburn]

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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>
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-- 
Gary Stainburn
Group I.T. Manager
Ringways Garages
http://www.ringways.co.uk