def colorize(self, image, nodata=None):
"""Returns a new RGBA VImage that has been colorized"""
if image.Bands() != 1:
raise ValueError("image {0!r} has more than one band".format(image))
logging.info("Coloring data")
logging.debug("Algorithm: {0} {1}".format(type(self).__name__, self))
# Convert to a numpy array
data = numpy.frombuffer(buffer=image.tobuffer(), dtype=image.NumPyType())
# Use numexpr to color the data as RGBA bands
bands = self._colorize_bands(data=data, nodata=nodata)
# Merge the bands into a single RGBA VImage
width, height = image.Xsize(), image.Ysize()
images = [
VImage.from_numpy_array(array=band, width=width, height=height, bands=1, format=VImage.FMTUCHAR)
for band in bands
]
return VImage.gbandjoin(bands=images)
