rasterio/tests/test_read_resample.py
2015-04-06 12:04:28 -06:00

34 lines
1.3 KiB
Python

import numpy
import rasterio
# Rasterio exposes GDAL's resampling/decimation on I/O. These are the tests
# that it does this correctly.
#
# Rasterio's test dataset is 718 rows by 791 columns.
def test_read_out_shape_resample_down():
with rasterio.open('tests/data/RGB.byte.tif') as s:
out = numpy.zeros((7, 8), dtype=rasterio.ubyte)
data = s.read(1, out=out)
expected = numpy.array([
[ 0, 8, 5, 7, 0, 0, 0, 0],
[ 0, 6, 61, 15, 27, 15, 24, 128],
[ 0, 20, 152, 23, 15, 19, 28, 0],
[ 0, 17, 255, 25, 255, 22, 32, 0],
[ 9, 7, 14, 16, 19, 18, 36, 0],
[ 6, 27, 43, 207, 38, 31, 73, 0],
[ 0, 0, 0, 0, 74, 23, 0, 0]], dtype=numpy.uint8)
assert (data == expected).all() # all True.
def test_read_out_shape_resample_up():
# Instead of testing array items, test statistics. Upsampling by an even
# constant factor shouldn't change the mean.
with rasterio.open('tests/data/RGB.byte.tif') as s:
out = numpy.zeros((7180, 7910), dtype=rasterio.ubyte)
data = s.read(1, out=out, masked=True)
assert data.shape == (7180, 7910)
assert data.mean() == s.read(1, masked=True).mean()