Bug 59179

Summary:	Some colors appear grey/black, whereas it works with Adobe Reader
Product:	poppler	Reporter:	Germán Poo-Caamaño <gpoo+bfdo>
Component:	cairo backend	Assignee:	poppler-bugs <poppler-bugs>
Status:	RESOLVED FIXED	QA Contact:
Severity:	normal
Priority:	medium
Version:	unspecified
Hardware:	Other
OS:	All
See Also:	https://bugzilla.gnome.org/show_bug.cgi?id=691430 https://bugs.freedesktop.org/show_bug.cgi?id=65780
Whiteboard:
i915 platform:		i915 features:
Attachments:	PDF test for color mismatch Screenshot of Acroread and Evince output support uncolored tiling patterns support uncolored tiling patterns

Description Germán Poo-Caamaño 2013-01-09 19:37:53 UTC

Created attachment 72749 [details]
PDF test for color mismatch

As it was reported in GNOME Bugzilla:

--------------------------------------------------------------
On one specific document that I have, some colors are not displayed correcly.
With Adode Reader, I have different colors. With Evince, everything is gray.

Here is the link to the document:
http://www.info.ucl.ac.be/~pecheur/talks/VVof2GRLV-FAABS02.pdf

Slide 13 has this issue: yellow, red and green are all gray. I've attached a a
picture showing how this slide is displayed by both pdf viewers.
--------------------------------------------------------------

I took out only the page 13 that shows the issue.  You will find it attached.
I can reproduce the problem with pdftocairo -png.

Comment 1 Germán Poo-Caamaño 2013-01-09 19:39:00 UTC

Created attachment 72750 [details]
Screenshot of Acroread and Evince output

Comment 2 Germán Poo-Caamaño 2013-01-09 19:41:06 UTC

I forgot to add:

I tested it against cairo 1.12 and poppler master (bef2c42f381c74fd,
the commit after 0.22.0).

Comment 3 Albert Astals Cid 2013-01-09 19:43:24 UTC

FWIW it works fine in splash

Comment 4 Adrian Johnson 2013-01-24 11:53:18 UTC

Created attachment 73562 [details] [review]
support uncolored tiling patterns

The cairo backend does not support uncolored tiling patterns. This caused uncolored patterns to be drawn in gray.

The attached patch fixes this.

Comment 5 Carlos Garcia Campos 2013-01-24 14:10:01 UTC

(In reply to comment #4)
> Created attachment 73562 [details] [review] [review]
> support uncolored tiling patterns
> 
> The cairo backend does not support uncolored tiling patterns. This caused
> uncolored patterns to be drawn in gray.
> 
> The attached patch fixes this.

This looks sane to me, but I'm getting a small regression in one of my files, I'll send the pdf file to you by email. Thanks

Comment 6 Adrian Johnson 2013-01-25 12:01:03 UTC

Created attachment 73644 [details] [review]
support uncolored tiling patterns

It turns out that we can't use cairo_mask for uncolored patterns since cairo_mask uses the alpha and not the luminosity to mask the source.

This patch uses the same solution as uncolored patterns in PSOutputDev. It adds a flag to indicate we are rendering an uncolored pattern and disables setting the color when the flag is true.

Comment 7 Carlos Garcia Campos 2013-01-28 14:57:15 UTC

(In reply to comment #6)
> Created attachment 73644 [details] [review] [review]
> support uncolored tiling patterns
> 
> It turns out that we can't use cairo_mask for uncolored patterns since
> cairo_mask uses the alpha and not the luminosity to mask the source.
> 
> This patch uses the same solution as uncolored patterns in PSOutputDev. It
> adds a flag to indicate we are rendering an uncolored pattern and disables
> setting the color when the flag is true.

Great, no regressions this time. Thanks! Please, don't use braces for single statement ifs. Feel free to push.

Comment 8 Adrian Johnson 2013-01-28 20:59:10 UTC

I've removed the surplus braces and pushed.

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