robinkraft/forma-vis — Issue #5: gdal2tiles resampling introduces pixel artifacts
Author: robinkraft
Created: 2011-11-12 23:49:21+00:00
State: open

Example:
http://elementstream.com/forma-vis/tiles/newecohack/10/824/515.png

If you zoom way in you can see borders on the real pixels.

The good news is that it's not a canvas-related problem. Nor is it an error in the original data. Turns out it's introduced by gdal2tiles.py, which by default resamples the original image using the average of the pixel neighborhood. I can regenerate the tiles using the nearest neighbor option, which should not change the pixel values (though it could shift them slightly - not enough to matter).

Solution: regenerate tiles using gdal2tiles using --resampling=near flag.