Downsample array in Python

python image-processing numpy scipy gdal
wuffwuff picture wuffwuff · Sep 6, 2013 · Viewed 43.5k times · Source

I have basic 2-D numpy arrays and I'd like to "downsample" them to a more coarse resolution. Is there a simple numpy or scipy module that can easily do this? I should also note that this array is being displayed geographically via Basemap modules.

SAMPLE: enter image description here

Answer

K.-Michael Aye picture K.-Michael Aye · Mar 17, 2015

scikit-image has implemented a working version of downsampling here, although they shy away from calling it downsampling for it not being a downsampling in terms of DSP, if I understand correctly:

http://scikit-image.org/docs/dev/api/skimage.measure.html#skimage.measure.block_reduce

but it works very well, and it is the only downsampler that I found in Python that can deal with np.nan in the image. I have downsampled gigantic images with this very quickly.

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