[cairo] pixman box filtering code prototype

Jeff Muizelaar jeff at infidigm.net
Thu Oct 9 11:08:16 PDT 2008

On Wed, Oct 08, 2008 at 11:45:28AM -0400, Aron Rubin wrote:
> Jeff Muizelaar wrote:
> > It works by projecting each pixel of the destination surface to a
> > parallelogram on the source surface.  All of the pixels in the
> > parallelogram are summed to produce the value of the destination pixel.
> > 
> > I've attached a patch against pixman revision
> > 6449782f8a4bea0274a30f86d56214c2c73c0303. It does not merge without
> > conflicts so it will need some manual merging.
> > 
> > I've also attached a test program that generates the output something
> > like: http://people.freedesktop.org/~jrmuizel/box-filter.png vs.  the
> > existing bilinear code at:
> > http://people.freedesktop.org/~jrmuizel/bilinear.png
> > 
> > This example isn't the best at showcasing the code because it's scaling
> > down a simple image and not scaling too much, however it was a very
> > useful test case for getting things correct.
> Where is the source image? The large A is different in each image.

The source image is now at http://people.freedesktop.org/~jrmuizel/a.png
The difference between the large A's is because of the different
upscaling between the two algorithms.


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