[poppler] Image optimization

Leonard Rosenthol leonardr at pdfsages.com
Sat May 21 17:36:57 PDT 2005

At 11:21 AM 5/21/2005, Jeff Muizelaar wrote:
> > > a nicer api.
> > Splash API is completely thought to fit xpdf, i can not think how an 
> API can
> > be nicer than that.
>It does fit xpdf well but it doesn't necessarily fit pdf well. It
>doesn't have support for transparency or shading.

         Splash supports transparency - in terms of maintaining an alpha 
channel for such elements.  It doesn't "flatten" them, but then I don't 
believe Cairo does either.

         Shadings are actually handled UP the chain in Xpdf - so that 
NEIHER Cairo nor Splash will see native shading operations...They are 
"dissected" down in the bowels of Xpdf and converted to simple 
primitives.  Same with patterns.

>It also is not very suited to hardware acceleration.


         If you want that - then do what Mac OS X and others are doing, use 
an OpenGL surface.

> > Well, imho as Carl said, it is because we are lacking a intermediate class
> > that both CairoOutputdev and SplashOutputDev should inherit and that 
> should
> > contain that lot of non Cairo/Splash dependant code both clases have.
>There isn't really a lot of this type of code. The only thing that
>really comes to mind is some of the path code. Certainly more such code
>could be made, but I don't think it is worth the effort.
         I suspect that a good chunk of the raster image handling is the 
same and basic font/character support (the stuff that happens before 
calling into FT).


Leonard Rosenthol                            <mailto:leonardr at pdfsages.com>
Chief Technical Officer                      <http://www.pdfsages.com>
PDF Sages, Inc.                              215-938-7080 (voice)
                                              215-938-0880 (fax)

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