[Gdal-dev] Resampling With GDAL

[Andrey Kiselev]

On Fri, Apr 20, 2007 at 02:53:36AM -0500, Mike Richardson wrote:
> At any rate, here is technique you can use to create smooth,
> anti-aliased resampled images with GDAL. It's not perfect and it is a
> bit more work but it does generate good results.

I would like to raise this issue again.

I have tried to solve the problem with downsampling using gdalwarp. I
have implemented filtered resampling and now -rcs option should work much
better. Please, try the new implementation of cubic spline filter (-rcs)
and Lanczos filter (-r lanczos) for both upsampling and downsampling
cases. Note, that new implementation works slower than the old one,
though there is a room for optimization. Nearest neighbour, bilinear and
cubic convolution scalers did not changed yet.

Updated implementation is available from the SVN HEAD. I am waiting for
feedback, so all parties interested in better scaling during warping are
welcome to test.

Best regards,
Andrey

-- 
Andrey V. Kiselev
ICQ# 26871517