Created attachment 141279 [details] [review]
Patch to add upsize sampler

Created attachment 141280 [details]
XML testcases for upsize sampler

These five testcases look for images big.png and small.png to be resampled using the upsize sampler.

Created attachment 141364 [details] [review]
Updated version of the upsize sampler

I was successfully able to install this patch.

This patch is ready to commit.

Timing tests: Summary: upsize (Nohalo level 2) is about as fast as the current GEGL bicubic.

Details:

Colour original is a 325x325 png (the "map") except for the
downsampling tests for which the original is a 1680x1680 png (the
"baby")

reduce (downsample) a lot (gegl:scale with x=y=.061):

bicubic:    1.530s
linear:     1.376s
upsize:     1.418s

reduce (gegl:scale with x=y=.53):

bicubic:    17.856s
linear:     17.276s
upsize:     18.139s 
 
rotate (gegl:rotate with degrees=7):

bicubic:    2.054s   
linear:     1.910s
upsize:     2.084s   

enlarge (upsample) (gegl:scale with x=y=1.81):

bicubic:    2.050s
linear:     1.618s
upsize:     2.028s  

enlarge a lot (gegl:scale with x=y=5.19):

bicubic:    14.587s   
linear:     11.767s
upsize:     14.990s

commit 130c793c70195cf900017f74505b863a3c29a6d5
Author: Adam Turcotte <adam.turcotte@gmail.com>
Date:   Fri Jan 15 17:33:13 2010 -0500

    Add new samplers from gsoc

(In reply to comment #7)
> commit 130c793c70195cf900017f74505b863a3c29a6d5
> Author: Adam Turcotte <adam.turcotte@gmail.com>
> Date:   Fri Jan 15 17:33:13 2010 -0500
> 
>     Add new samplers from gsoc

My student Chantal Racette and I have programmed a new gegl-sampler-upsize.c. This version is ready for prime time. Try it! It's basically Catmull-Rom with almost no haloing and slightly reduced staircasing. Patch included.

Created attachment 157340 [details] [review]
Major upgrade of the gegl-sampler-upsize.c sampler

"Ready for prime time," high quality nonlinear resampler.

Created attachment 157341 [details]
Quick visual test file for upsize sampler: enlarge car-stack 16 times

Put this in gegl/tests/compositions and run with

gegl upsizecars.xml -o upsizecars.png

(In reply to comment #10)
> Created an attachment (id=157341) [details]
> Quick visual test file for upsize sampler: enlarge car-stack 16 times
> 
> Put this in gegl/tests/compositions and run with
> 
> gegl upsizecars.xml -o upsizecars.png

(Actually only 2.57 times.)

I'm creating a new bugzilla for the brand new upsize and upsharp.