[poppler] color inversion for a mask image

[Albert Astals Cid]

El Dijous, 29 de març de 2012, a les 23:12:44, Ihar `Philips` Filipau va 
escriure:
> Nope. Not it.
> 
> I have tested it against the Splash: SplashOutputDev displays the
> image as it should be, HtmlOutputDev - not. In both cases, the Decode
> array indicates no inversion (and drawImageMask() is called with
> invert=false). There is something else in the GfxState which affects
> how the mask is painted.
> 
> After looking at the Splash code which does it right, and imagining
> potential reimplementation say half of it in HtmlOutputDev, honestly,
> I'd rather live with the pdftohtml occasionally writing a monochrome
> image inverted. (ImageMagick's `convert -negate` does the job.)
> 
> If the GfxState/etc had some sort of a way to dump the state - with
> some human explanations :) - so that it could be investigated with
> naked eyes, I might have tried to find it. But as it is, 


> since I'm doing it on my spare time, 

Welcome to the club :-)

Albert

> it is pretty much unrealistic for me to
> find it. And for just one image - totally pointless, I have to admit.
> 
> But thanks for your help anyway!
> 
> P.S. Have tried couple of pdf2* alternatives - the same behavior.
> poppler's pdfimages likewise doesn't invert the image.
> 
> On 3/29/12, Leonard Rosenthol <lrosenth at adobe.com> wrote:
> > I can't speak to the Gfxstate, but there are keys in the image dictionary
> > (such as Decode) that relate to inversion.
> > 
> > Leonard
> > 
> > On 3/29/12 2:09 AM, "Ihar `Philips` Filipau" <thephilips at gmail.com> wrote:
> >>Hi All!
> >>
> >>I have encountered minor yet interesting problem. With the
> >>functionality I have recently added to pdftohtml, now also the mask
> >>images are extracted (as PNGs).
> >>
> >>In one document I have, one mask image is extracted with colors
> >>inverted: white is black, black is white. Yet, it is displayed by all
> >>the PDF viewers correctly.
> >>
> >>Is there any flag/etc in GfxState/etc which might be responsible for
> >>color inversion? the flag pdftohtml doesn't check yet?
> >>
> >>Thanks.
> >>_______________________________________________
> >>poppler mailing list
> >>poppler at lists.freedesktop.org
> >>http://lists.freedesktop.org/mailman/listinfo/poppler