Cropping GeoImages

[lematt1991]

Would it be possible to add functionality to crop a GeoImage? It would be great if you could specify either the indices of the subset that you would like to crop out or even the bounds in lat/lon coordinates. Cropping out the data would be trivial, but the projection information would also need to be updated.

[longbotham]

passing return_location=True to get_data or the iter_xxx functions should do what you're asking for. You can then either use the new geo_transform info directly in python or write the pixels back to a file on disk with create_geo_image. You can also pass a geom directly to get_data if you have a single geometry you want to cut to - see the code for iter_vector under the example below for details.

import geoio
import dgsamples

vec_str = dgsamples.wv2_longmont_1k_vectors.poly_geojson_utm
img = geoio.DGImage(dgsamples.wv2_longmont_1k.ms)

for x in img.iter_vector(vec_str, return_location=True):
        fname = 'tmp'+'_'.join([str(p) for p in x[1]['upper_left_pixel']])+'.tif'
        dtype = geoio.constants.DICT_NP_TO_GDAL[x[0].dtype]
        geoio.base.create_geo_image(fname,
                                    x[0],
                                    'GTiff',
                                    x[1]['geo_transform'],
                                    img.meta.projection_string,
                                    dtype)

[lematt1991]

Yep, that's exactly what I was looking for. Thanks!