Source code for rios.imageio

#!/usr/bin/env python

This file contains definitions that are
common to all the image reading and 
writing modules
# This file is part of RIOS - Raster I/O Simplification
# Copyright (C) 2012  Sam Gillingham, Neil Flood
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# GNU General Public License for more details.
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <>.

import numpy
from osgeo import gdalconst

from . import rioserrors

BOUNDS_FROM_REFERENCE = 2       # Bounds of working region are taken from given reference grid

[docs]class Coord: """a simple class that contains one coord""" def __init__(self, x, y): self.x = x self.y = y
[docs]def wld2pix(transform, geox, geoy): """converts a set of map coords to pixel coords""" x = (transform[0] * transform[5] - transform[2] * transform[3] + transform[2] * geoy - transform[5] * geox) / (transform[2] * transform[4] - transform[1] * transform[5]) y = (transform[1] * transform[3] - transform[0] * transform[4] - transform[1] * geoy + transform[4] * geox) / (transform[2] * transform[4] - transform[1] * transform[5]) return Coord(x, y)
[docs]def pix2wld(transform, x, y): """converts a set of pixels coords to map coords""" geox = transform[0] + transform[1] * x + transform[2] * y geoy = transform[3] + transform[4] * x + transform[5] * y return Coord(geox, geoy)
# Mappings between numpy datatypes and GDAL datatypes. # Note that ambiguities are resolved by the order - the first one found # is the one chosen. dataTypeMapping = [ (numpy.uint8, gdalconst.GDT_Byte), (numpy.bool, gdalconst.GDT_Byte), (numpy.int16, gdalconst.GDT_Int16), (numpy.uint16, gdalconst.GDT_UInt16), (numpy.int32, gdalconst.GDT_Int32), (numpy.uint32, gdalconst.GDT_UInt32), (numpy.single, gdalconst.GDT_Float32), (numpy.float, gdalconst.GDT_Float64) ] # hack for GDAL 3.5 and later which suppport 64 bit ints if hasattr(gdalconst, 'GDT_Int64'): dataTypeMapping.append((numpy.int64, gdalconst.GDT_Int64)) dataTypeMapping.append((numpy.uint64, gdalconst.GDT_UInt64))
[docs]def GDALTypeToNumpyType(gdaltype): """ Given a gdal data type returns the matching numpy data type """ for (numpy_type, test_gdal_type) in dataTypeMapping: if test_gdal_type == gdaltype: return numpy_type raise rioserrors.TypeConversionError("Unknown GDAL datatype: %s"%gdaltype)
[docs]def NumpyTypeToGDALType(numpytype): """ For a given numpy data type returns the matching GDAL data type """ for (test_numpy_type, gdaltype) in dataTypeMapping: if test_numpy_type == numpytype: return gdaltype raise rioserrors.TypeConversionError("Unknown numpy datatype: %s"%numpytype)