[poppler] color inversion for a mask image
lrosenth at adobe.com
Thu Mar 29 15:04:07 PDT 2012
If you want to post the PDF, we can give you the EXACT thing to look for.
Otherwise, we're just guessing!
On 3/29/12 11:12 PM, "Ihar `Philips` Filipau" <thephilips at gmail.com> wrote:
>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, 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
>> (such as Decode) that relate to inversion.
>> On 3/29/12 2:09 AM, "Ihar `Philips` Filipau" <thephilips at gmail.com>
>>>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?
>>>poppler mailing list
>>>poppler at lists.freedesktop.org
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