[poppler] Getting a raster image like pdf2ppm

[Albert Astals Cid]

A Dijous, 21 de maig de 2009, Angus March va escriure:
> Albert Astals Cid wrote:
> > A Dimecres, 20 de maig de 2009, Angus March va escriure:
> >> Albert Astals Cid wrote:
> >>> A Dimarts, 19 de maig de 2009, Angus March va escriure:
> >>>> Adrian Johnson wrote:
> >>>>> Angus March wrote:
> >>>>>> I tried using Poppler to get a Cairo surface and then saving the
> >>>>>> surface to a PNG. Unfortunately, the resulting image was of
> >>>>>> disastrously low quality.
> >>>>>
> >>>>> Without seeing your code or the output you are getting I can only
> >>>>> guess at what the problem might be. Did you alter the cairo scale to
> >>>>> get the desired image dpi?
> >>>>
> >>>>     It was definitely an improvement, but I think the only thing that
> >>>> did improve was the resolution. The old problems that caused me to
> >>>> abandon Cairo persisted, which are: gradients have ugly stripes on
> >>>> them, a background that should be white and opaque is black and
> >>>> transparent, and some text that has a shadow in the PDF doesn't in the
> >>>> image. I don't suppose you know of a way to deal w/those problems.
> >>>
> >>> ?
> >>>
> >>> I don't see anything obviously wrong.
> >>>
> >>> Basically it is:
> >>>  * Create PDFDoc
> >>>  * Create SplashOutputDev
> >>>  * Call SplashOutputDev::startDoc
> >>>  * Call PDFDoc::displayPageSlice
> >>
> >>     Well there definitely is something wrong, because it works with
> >> pdftoppm. I thought of things like the __attribute__((constructor))
> >> attribute, or static objects, but I don't see any evidence of the
> >> attribute and I wouldn't know how to find a static object in all that
> >> code. Maybe multiple processes causes problems for Splash.
> >>
> >>
> >>
> >> It's hard to know where to go.
> >
> > The crashes you pasted are from poppler compiled with -O2? If so remove
> > the - O2 and substitute -g by -g3. Optimized poppler backtraces are
> > really misleading.
>
>     I figured out a way to get my app to build from the poppler lib I
> rolled myself (although I'd still like to know what the proper procedure
> is to get it to build in debug, and install the Splash stuff) and I got
> some valgrind reports that might be more helpful, but are fewer than
> those I got when I was using the SUSE distro's lib:
>
> ==8577== Conditional jump or move depends on uninitialised value(s)
> ==8577==    at 0x53DACE4: FoFiType1C::parse() (FoFiType1C.cc:1848)
> ==8577==    by 0x53E10AB: FoFiType1C::make(char*, int) (FoFiType1C.cc:35)
> ==8577==    by 0x5369A58: Gfx8BitFont::Gfx8BitFont(XRef*, char*, Ref,
> GooString*, GfxFontType, Dict*) (GfxFont.cc:699)
> ==8577==    by 0x536D72C: GfxFont::makeFont(XRef*, char*, Ref, Dict*)
> (GfxFont.cc:143)
> ==8577==    by 0x536D933: GfxFontDict::GfxFontDict(XRef*, Ref*, Dict*)
> (GfxFont.cc:2051)
> ==8577==    by 0x535AD21: GfxResources::GfxResources(XRef*, Dict*,
> GfxResources*) (Gfx.cc:313)
> ==8577==    by 0x535DD6B: Gfx::Gfx(XRef*, OutputDev*, int, Dict*,
> Catalog*, double, double, PDFRectangle*, PDFRectangle*, int, int
> (*)(void*), void*) (Gfx.cc:502)
> ==8577==    by 0x539AF12: Page::createGfx(OutputDev*, double, double,
> int, int, int, int, int, int, int, int, Catalog*, int (*)(void*), void*,
> int (*)(Annot*, void*), void*) (Page.cc:404)
> ==8577==    by 0x539B173: Page::displaySlice(OutputDev*, double, double,
> int, int, int, int, int, int, int, int, Catalog*, int (*)(void*), void*,
> int (*)(Annot*, void*), void*) (Page.cc:433)
> ==8577==    by 0x40A756: pdf2jpg::GetSplash(int) (pdf2jpg.cpp:176)
> ==8577==    by 0x40A9B5: pdf2jpg::TopupJpegThreads(int, astring const&)
> (pdf2jpg.cpp:156)
> ==8577==    by 0x40B3B1: pdf2jpg::Execute(int, char const*, char const*,
> int) (pdf2jpg.cpp:99)
> ==8577==

Are you positively sure this doesn't happen with pdftoppm? Doesn't make any 
sense.

Albert