[cairo] Where's the bottleneck in using glitz/cairo/librsvg?

[Jeff Muizelaar]

On Thu, Jun 08, 2006 at 10:36:07AM -0700, Carl Worth wrote:
> On Thu, 8 Jun 2006 09:20:45 +0300, "Koichi Mori" wrote:
> > Scaling raster image, especially down scaling, does not necessarily generate
> > horrible result if filtered. Even bi-linear filtering should give quite good
> > enough quality for icons.
> 
> Cairo's software has a bi-linear filter. And when downscaling at a
> factor greater than 2 the quality gets increasingly objectionable,
> (and quite soon gets to something I would call horrible) . So unless
> bi-linear means something very different than what cairo is doing,
> it's definitely not sufficient for all downscaling.
> 
> Incidentally, this ugly downscaling is one of the few ways in which
> cairo will produce poor-quality results even when give high-quality
> input[*]. So it's definitely something that I'd like to see fixed in
> cairo.
> 
> Some people have proposed doing some sort of mip-mapping or Laplacian
> pyramid for better-quality downscaling, but I haven't seen any
> implementation progress on this front yet.

I too would love to see this fixed. This problem is one of the biggest
quality disadvantages to using the poppler cairo backend. It makes
bitmap fonts look pretty terrible.

-Jeff