Re: Downsampling interpolation
"Bryce W. Harrington" <[email protected]>
| Newsgroups | gmane.comp.lib.cairo |
|---|---|
| Message-ID | <[email protected]> |
On Fri, Aug 09, 2013 at 12:19:10AM +0000, Bryce W. Harrington wrote: > On Tue, Aug 06, 2013 at 10:01:39AM -0400, Hunter Loftis wrote: > > Hi everyone - new to cairo, just browsed through a bunch of old discussions and commits to learn about the < 0.5 downsampling issue (cairo always linearly interpolates between two values, so at < 0.5 results look terrible). > > > > Is there any path to a solution within cairo, or would that be terribly complex? My alternative is to repeatedly downsample at 0.5 until the ratio is > 0.5 in order to hit my downsample target. Obviously pretty kludgy but it'd get the job done. > > > > Did you look at the downscaling patch that was posted about a month ago? > I believe it's still on the docket to go in after the next release. > > If you'd like, I can stick it into a git tree for you. I've been > working on some tests to go along with it. I've posted this patch along with the tests here: http://cgit.freedesktop.org/~bryce/cairo/ # branch = downscaling Note you may need a newer version of pixman than provided by your distro. I just did a git checkout of current pixman, built it, then built cairo against it like this: pixman_CFLAGS="-I/home/bryce/src/pixman/pixman/pixman/" \ pixman_LIBS="-L/home/bryce/src/pixman/pixman/pixman/ -lpixman-1" \ ./configure make (Fwiw, the tests are still a WIP; I've got a few changes I need to do before they're ready to go mainline.) Bryce -- cairo mailing list [email protected] http://lists.cairographics.org/mailman/listinfo/cairo