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

[Dan Walker]

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.
>>
>>
>