TechWriter Pro 9.12

G'day folks,

I'm doing some testing for someone and have encountered a little thing
which has me perplexed.

http://www.triffid.co.uk/dstuff/Techtest.zip contains a TechWriter file,
it contains four identical images in different file types, so they were
put in to the TechWriter document as...

Jpeg
PNG
BMP
Sprite

In TechWriter, if I do Menu-Save-PDF the resulting PDF document has the
Jpeg in colour, but the other filetype images are all Greyscale.

It doesn't matter what order the images are in the TechWriter document,
the output PDF has the Jpeg in colour and the others in Greyscale.

Any thoughts please?

Thanks
Dave


Nb:

If the document is Printed out of TechWriter using Steve Fryatt's PrintPDF
the resulting PDF has all the images in colour.
So GhostScript is working okay.

D.

--

Dave Triffid

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In article <596f8061c0dave@triffid.co.uk>,
Dave <dave@triffid.co.uk> wrote:
[Snippy]

Nb:

If the document is Printed out of TechWriter using Steve Fryatt's
PrintPDF the resulting PDF has all the images in colour. So GhostScript
is working okay.

D.

Slight aside but worth a mention...

I put the four different filetype images in ArtWorks2, Exported as PDF,
the resulting PDF has all the images in colour.

The problem seems specific to TechWriter.

?

Dave

--

Dave Triffid

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In article <596f8061c0dave@triffid.co.uk>,
Dave <dave@triffid.co.uk> wrote:

<snip>

Any thoughts please?

I don't know the answer to your question but, if there's no
satisfaction on this newsgroup, I suggest you try the
mailing list icon-users@freelists.org .

John

--
John
newsmcc@blueyonder.co.uk
j dot mccartney atte blueyonder dot co dot uk

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In article <596f8061c0dave@triffid.co.uk>,
Dave <dave@triffid.co.uk> wrote:

Any thoughts please?

No thoughts. I've fed your file to 3 PDF readers (!PDF, !PDFView and
!Muview), and they all show every picture in full colour.

TechWriter 9.12, RISC OS 5.29

Kind regards,
Paul Sprangers

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In message <596f8061c0dave@triffid.co.uk>
Dave <dave@triffid.co.uk> wrote:

In TechWriter, if I do Menu-Save-PDF the resulting PDF document has the
Jpeg in colour, but the other filetype images are all Greyscale.

If the document is Printed out of TechWriter using Steve Fryatt's PrintPDF the resulting PDF has all the images in colour.
So GhostScript is working okay.

I put the four different filetype images in ArtWorks2, Exported as PDF,
the resulting PDF has all the images in colour.

ArtWorks saves the PDF itself, whereas TechWriter needs a Postscript
printer driver available so that it can "print" it to the file, so the
problem willl be in how !Printers is setup.

What printer driver is PrintPDF setup to use, and is TechWriter also using
that one? I've no idea how it picks if you have more than one Postscript
driver available.

Check that all your PS printers have the Colour option ticked in their configuration window.

Bryan.

--
RISC OS User Group Of London - http://www.rougol.jellybaby.net/
RISC OS London Show - http://www.riscoslondonshow.co.uk/

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In article <d8a4a56f59.bryan@helpful-demon.co.uk>,
Bryan Hogan <spam@nowhere.invalid> wrote:

In message <596f8061c0dave@triffid.co.uk>
Dave <dave@triffid.co.uk> wrote:

In TechWriter, if I do Menu-Save-PDF the resulting PDF document has the Jpeg in colour, but the other filetype images are all Greyscale.

If the document is Printed out of TechWriter using Steve Fryatt's
PrintPDF the resulting PDF has all the images in colour. So
GhostScript is working okay.

I put the four different filetype images in ArtWorks2, Exported as
PDF, the resulting PDF has all the images in colour.

ArtWorks saves the PDF itself, whereas TechWriter needs a Postscript
printer driver available so that it can "print" it to the file, so the problem willl be in how !Printers is setup.

What printer driver is PrintPDF setup to use, and is TechWriter also
using that one? I've no idea how it picks if you have more than one Postscript driver available.

Check that all your PS printers have the Colour option ticked in their configuration window.

Bryan.

Ah!

I don't know how all this (Excrement) is supposed to work, I just assumed TechWriter has all the required stuff to do the business...

GOOD catch Brian, I didn't realise TW would print to PDF file through my default printer HPLaserjet-ps driver. (A B&W printer).

Anyway, ticking the Colour button On in the HPLJ PS printer
configurations and thereafter the TW PDF output is now all colour.

Excellent, so thanks for that insight, appreciated. :-)

Dave

But it does leave me with one remaining confusion... :-(

Why then, before I switched colour On in the driver, were previous PDFs printing the Jpegs in colour, but the other file type images in the
document were greyscale?

That's just not logical... (I've posted the relevant PDF upline if you
don't believe me). http://www.triffid.co.uk/dstuff/Techtestsave.pdf

Dr my brain hurts...

Dave

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Dave Triffid

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On Wednesday, September 22, 2021 at 7:29:13 AM UTC+1, Dave wrote:

Why then, before I switched colour On in the driver, were previous PDFs printing the Jpegs in colour, but the other file type images in the
document were greyscale?

I noticed that a couple of years ago too, and finally got round to looking into it a few weeks back.

It's a bug (or misoptimisation) in the Level 2 driver which embeds the JPEG directly in the PostScript output - this wasn't possible at Level 1 because I think that standard preceded the standardisation of the JPEG file format. I guess nobody noticed
before because if you send a colour JPEG to a B&W printer it'll print /something/ reasonable, but in the age of the paperless office when we turn many documents into PDF it's more obvious!

There's a fix in review with RISC OS Open at the moment
https://gitlab.riscosopen.org/RiscOS/Sources/Printing/Modules/PDModules/-/merge_requests/1

so once that's made it over the line there will be an updated !Printers which you can grab to get the fix,
Sprow.

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In article <a14a7dec-db2f-495f-a24a-96604a979e88n@googlegroups.com>,
Sprow <news@sprow.co.uk> wrote:

On Wednesday, September 22, 2021 at 7:29:13 AM UTC+1, Dave wrote:

Why then, before I switched colour On in the driver, were previous
PDFs printing the Jpegs in colour, but the other file type images in
the document were greyscale?

I noticed that a couple of years ago too, and finally got round to
looking into it a few weeks back.

It's a bug (or misoptimisation) in the Level 2 driver which embeds the
JPEG directly in the PostScript output - this wasn't possible at Level 1 because I think that standard preceded the standardisation of the JPEG
file format. I guess nobody noticed before because if you send a colour
JPEG to a B&W printer it'll print /something/ reasonable, but in the age
of the paperless office when we turn many documents into PDF it's more obvious!

There's a fix in review with RISC OS Open at the moment
https://gitlab.riscosopen.org/RiscOS/Sources/Printing/Modules/PDModules/-/merge_requests/1

so once that's made it over the line there will be an updated !Printers
which you can grab to get the fix, Sprow.

Thanks for that illumination Sprow, I understand.

Dave


Leaves one small question.
For most of my RISC OS stuff I'm not using RISC OS 5.nn but 6.20 and
Printers 1.91a, would that fix be of any use to the 6.20 printers?

Thanks
Dave

--

Dave Triffid

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