On 2020-10-16 11:49 a.m., Nicolas Cadieux wrote:
Hi again! (a few months later...)
What is the best practice for reading a single pixel in the raster?
structval = raster_band.ReadRaster(column, row, 1, 1, 1, 1,
raster_band.DataType)
or
structval = raster_band.ReadRaster(int(column), int(row), 1, 1, 1, 1,
raster_band.DataType)
Nicolas
On 2020-01-28 12:30 p.m., Even Rouault wrote:
Nicolas,
It's easy to go from coordinate space to pixel space in python using
something like.
pixel_x = int(-124114.3 - geo_transform[0])/geo_transform[1])
What is the trick when there is an image rotation?
Compute the inverse geotransform with
https://gdal.org/api/raster_c_api.html?highlight=invgeotransform#_CPPv419GDALInvGeoTransformPdPd
(gdal.InvGeoTransform(gt) in Python )
And then use the coordinates in coordinate space as the input for
this inverse geotransform
column = inv_gt[0] + X * inv_gt[1] + Y * inv_gt[2]
row = inv_gt[3] + X * inv_gt[4] + Y * inv_gt[5]
Also, as a second
very beginner question, what is the difference between geo_transform[2]
and geo_transform[4]?
There are defined by the relationships at
https://gdal.org/user/raster_data_model.html#affine-geotransform
Even
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