# Raster Utilities¶

Django-raster hosts some utilities that ease the interaction with raster data. The functions are located in raster.utils and raster.tiles.utils.

pixel_value_from_point(raster, point, band=0)

Return the pixel value for the coordinate of the input point from selected band.

The input can be a point or tuple, if its a tuple it is assumed to be a pair of coordinates in the reference system of the raster. The band index to be used for extraction can be specified with the band keyword.

Example:

# Create a raster.
>>> raster = GDALRaster({
'width': 5,
'height': 5,
'srid': 4326,
'bands': [{'data': range(25)}],
'origin': (2, 2),
'scale': (1, 1)
})
# Create a point at origin
>>> point = OGRGeometry('SRID=4326;POINT(2 2)')
# Get pixel value at origin.
>>> pixel_value_from_point(raster, point)
... 0
# Get pixel value from within the raster, using coordinate tuple input.
>>> pixel_value_from_point(raster, (2, 3.5))
... 5