Added RasterSource/GDALBand GDAL objects
Based on Daniel Wiesmann's raster branch. Thanks Daniel Wiesmann and Tim Graham for the reviews. Refs #23804.
This commit is contained in:
Claude Paroz
parent
9fecb86a52
commit
6e08bde8c4
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@ -26,6 +26,7 @@ recursive-include django/contrib/formtools/tests/templates *
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recursive-include django/contrib/formtools/tests/wizard/wizardtests/templates *
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recursive-include django/contrib/flatpages/fixtures *
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recursive-include django/contrib/flatpages/tests/templates *
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recursive-include django/contrib/gis/gdal/tests/data *
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recursive-include django/contrib/gis/static *
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recursive-include django/contrib/gis/templates *
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recursive-include django/contrib/gis/tests/data *
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@ -47,6 +47,7 @@ try:
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from django.contrib.gis.gdal.driver import Driver # NOQA
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from django.contrib.gis.gdal.datasource import DataSource # NOQA
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from django.contrib.gis.gdal.libgdal import gdal_version, gdal_full_version, GDAL_VERSION # NOQA
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from django.contrib.gis.gdal.raster.source import GDALRaster # NOQA
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from django.contrib.gis.gdal.srs import SpatialReference, CoordTransform # NOQA
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from django.contrib.gis.gdal.geometries import OGRGeometry # NOQA
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HAS_GDAL = True
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@ -54,8 +54,8 @@ get_band_ds = voidptr_output(lgdal.GDALGetBandDataset, [c_void_p])
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get_band_datatype = int_output(lgdal.GDALGetRasterDataType, [c_void_p])
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get_band_nodata_value = double_output(lgdal.GDALGetRasterNoDataValue, [c_void_p, POINTER(c_int)])
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set_band_nodata_value = void_output(lgdal.GDALSetRasterNoDataValue, [c_void_p, c_double])
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get_band_minimum = double_output(lgdal.GDALGetRasterMinimum, [c_void_p])
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get_band_maximum = double_output(lgdal.GDALGetRasterMaximum, [c_void_p])
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get_band_minimum = double_output(lgdal.GDALGetRasterMinimum, [c_void_p, POINTER(c_int)])
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get_band_maximum = double_output(lgdal.GDALGetRasterMaximum, [c_void_p, POINTER(c_int)])
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### Reprojection routine ###
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reproject_image = void_output(lgdal.GDALReprojectImage, [c_void_p, c_char_p, c_void_p, c_char_p,
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@ -0,0 +1,69 @@
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from ctypes import byref, c_int
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from django.contrib.gis.gdal.base import GDALBase
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from django.contrib.gis.gdal.prototypes import raster as capi
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from django.utils.encoding import force_text
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from .const import GDAL_PIXEL_TYPES
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class GDALBand(GDALBase):
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"""
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Wraps a GDAL raster band, needs to be obtained from a GDALRaster object.
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"""
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def __init__(self, source, index):
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self.source = source
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self.ptr = capi.get_ds_raster_band(source.ptr, index)
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@property
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def description(self):
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"""
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Returns the description string of the band.
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"""
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return force_text(capi.get_band_description(self.ptr))
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@property
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def width(self):
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"""
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Width (X axis) in pixels of the band.
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"""
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return capi.get_band_xsize(self.ptr)
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@property
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def height(self):
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"""
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Height (Y axis) in pixels of the band.
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"""
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return capi.get_band_ysize(self.ptr)
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def datatype(self, as_string=False):
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"""
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Returns the GDAL Pixel Datatype for this band.
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"""
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dtype = capi.get_band_datatype(self.ptr)
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if as_string:
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dtype = GDAL_PIXEL_TYPES[dtype]
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return dtype
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@property
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def min(self):
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"""
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Returns the minimum pixel value for this band.
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"""
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return capi.get_band_minimum(self.ptr, byref(c_int()))
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@property
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def max(self):
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"""
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Returns the maximum pixel value for this band.
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"""
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return capi.get_band_maximum(self.ptr, byref(c_int()))
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@property
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def nodata_value(self):
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"""
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Returns the nodata value for this band, or None if it isn't set.
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"""
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nodata_exists = c_int()
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value = capi.get_band_nodata_value(self.ptr, nodata_exists)
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return value if nodata_exists else None
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@ -0,0 +1,19 @@
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"""
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GDAL - Constant definitions
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"""
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# See http://www.gdal.org/gdal_8h.html#a22e22ce0a55036a96f652765793fb7a4
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GDAL_PIXEL_TYPES = {
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0: 'GDT_Unknown', # Unknown or unspecified type
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1: 'GDT_Byte', # Eight bit unsigned integer
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2: 'GDT_UInt16', # Sixteen bit unsigned integer
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3: 'GDT_Int16', # Sixteen bit signed integer
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4: 'GDT_UInt32', # Thirty-two bit unsigned integer
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5: 'GDT_Int32', # Thirty-two bit signed integer
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6: 'GDT_Float32', # Thirty-two bit floating point
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7: 'GDT_Float64', # Sixty-four bit floating point
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8: 'GDT_CInt16', # Complex Int16
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9: 'GDT_CInt32', # Complex Int32
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10: 'GDT_CFloat32', # Complex Float32
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11: 'GDT_CFloat64', # Complex Float64
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}
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@ -0,0 +1,155 @@
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from ctypes import addressof, byref, c_double
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import os
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from django.contrib.gis.gdal.base import GDALBase
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from django.contrib.gis.gdal.driver import Driver
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from django.contrib.gis.gdal.error import GDALException
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from django.contrib.gis.gdal.prototypes import raster as capi
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from django.contrib.gis.gdal.raster.band import GDALBand
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from django.contrib.gis.gdal.srs import SpatialReference, SRSException
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from django.utils import six
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from django.utils.six.moves import range
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from django.utils.encoding import (force_bytes, force_text,
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python_2_unicode_compatible)
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from django.utils.functional import cached_property
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class TransformPoint(list):
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indices = {
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'origin': (0, 3),
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'scale': (1, 5),
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'skew': (2, 4),
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}
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def __init__(self, raster, prop):
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x = raster.geotransform[self.indices[prop][0]]
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y = raster.geotransform[self.indices[prop][1]]
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list.__init__(self, [x, y])
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self._raster = raster
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self._prop = prop
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@property
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def x(self):
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return self[0]
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@property
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def y(self):
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return self[1]
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@python_2_unicode_compatible
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class GDALRaster(GDALBase):
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"""
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Wraps a raster GDAL Data Source object.
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"""
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def __init__(self, ds_input, write=False):
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self._write = 1 if write else 0
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Driver.ensure_registered()
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# If input is a valid file path, try setting file as source.
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if isinstance(ds_input, six.string_types):
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if os.path.exists(ds_input):
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try:
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# GDALOpen will auto-detect the data source type.
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self.ptr = capi.open_ds(force_bytes(ds_input), self._write)
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except GDALException as err:
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raise GDALException('Could not open the datasource at "{}" ({}).'.format(
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ds_input, err))
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else:
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raise GDALException('Unable to read raster source input "{}"'.format(ds_input))
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else:
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raise GDALException('Invalid data source input type: "{}".'.format(type(ds_input)))
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def __del__(self):
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if self._ptr and capi:
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capi.close_ds(self._ptr)
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def __str__(self):
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return self.name
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def __repr__(self):
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"""
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Short-hand representation because WKB may be very large.
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"""
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return '<Raster object at %s>' % hex(addressof(self.ptr))
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@property
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def name(self):
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return force_text(capi.get_ds_description(self.ptr))
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@cached_property
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def driver(self):
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ds_driver = capi.get_ds_driver(self.ptr)
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return Driver(ds_driver)
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@property
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def width(self):
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"""
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Width (X axis) in pixels.
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"""
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return capi.get_ds_xsize(self.ptr)
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@property
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def height(self):
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"""
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Height (Y axis) in pixels.
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"""
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return capi.get_ds_ysize(self.ptr)
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@property
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def srs(self):
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"""
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Returns the Spatial Reference used in this GDALRaster.
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"""
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try:
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wkt = capi.get_ds_projection_ref(self.ptr)
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return SpatialReference(wkt, srs_type='wkt')
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except SRSException:
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return None
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@cached_property
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def geotransform(self):
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"""
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Returns the geotransform of the data source.
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Returns the default geotransform if it does not exist or has not been
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set previously. The default is (0.0, 1.0, 0.0, 0.0, 0.0, -1.0).
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"""
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# Create empty ctypes double array for data
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gtf = (c_double * 6)()
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capi.get_ds_geotransform(self.ptr, byref(gtf))
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return tuple(gtf)
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@property
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def origin(self):
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return TransformPoint(self, 'origin')
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@property
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def scale(self):
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return TransformPoint(self, 'scale')
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@property
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def skew(self):
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return TransformPoint(self, 'skew')
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@property
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def extent(self):
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"""
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Returns the extent as a 4-tuple (xmin, ymin, xmax, ymax).
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"""
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# Calculate boundary values based on scale and size
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xval = self.origin.x + self.scale.x * self.width
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yval = self.origin.y + self.scale.y * self.height
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# Calculate min and max values
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xmin = min(xval, self.origin.x)
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xmax = max(xval, self.origin.x)
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ymin = min(yval, self.origin.y)
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ymax = max(yval, self.origin.y)
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return xmin, ymin, xmax, ymax
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@cached_property
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def bands(self):
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bands = []
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for idx in range(1, capi.get_ds_raster_count(self.ptr) + 1):
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bands.append(GDALBand(self, idx))
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return bands
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@ -34,7 +34,7 @@ from django.contrib.gis.gdal.error import SRSException
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from django.contrib.gis.gdal.prototypes import srs as capi
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from django.utils import six
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from django.utils.encoding import force_bytes
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from django.utils.encoding import force_bytes, force_text
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#### Spatial Reference class. ####
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@ -46,16 +46,19 @@ class SpatialReference(GDALBase):
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"""
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#### Python 'magic' routines ####
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def __init__(self, srs_input=''):
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def __init__(self, srs_input='', srs_type='user'):
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"""
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Creates a GDAL OSR Spatial Reference object from the given input.
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The input may be string of OGC Well Known Text (WKT), an integer
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EPSG code, a PROJ.4 string, and/or a projection "well known" shorthand
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string (one of 'WGS84', 'WGS72', 'NAD27', 'NAD83').
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"""
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srs_type = 'user'
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if isinstance(srs_input, six.string_types):
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if srs_type == 'wkt':
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self.ptr = capi.new_srs(c_char_p(b''))
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self.import_wkt(srs_input)
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return
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elif isinstance(srs_input, six.string_types):
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# Encoding to ASCII if unicode passed in.
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if isinstance(srs_input, six.text_type):
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srs_input = srs_input.encode('ascii')
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@ -232,7 +235,7 @@ class SpatialReference(GDALBase):
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elif self.geographic:
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units, name = capi.angular_units(self.ptr, byref(c_char_p()))
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if name is not None:
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name.decode()
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name = force_text(name)
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return (units, name)
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#### Spheroid/Ellipsoid Properties ####
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Binary file not shown.
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@ -0,0 +1,118 @@
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"""
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gdalinfo django/contrib/gis/gdal/tests/data/raster.tif:
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Driver: GTiff/GeoTIFF
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Files: django/contrib/gis/gdal/tests/data/raster.tif
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Size is 163, 174
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Coordinate System is:
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PROJCS["NAD83 / Florida GDL Albers",
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GEOGCS["NAD83",
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DATUM["North_American_Datum_1983",
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SPHEROID["GRS 1980",6378137,298.2572221010002,
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AUTHORITY["EPSG","7019"]],
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TOWGS84[0,0,0,0,0,0,0],
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AUTHORITY["EPSG","6269"]],
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PRIMEM["Greenwich",0],
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UNIT["degree",0.0174532925199433],
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AUTHORITY["EPSG","4269"]],
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PROJECTION["Albers_Conic_Equal_Area"],
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PARAMETER["standard_parallel_1",24],
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PARAMETER["standard_parallel_2",31.5],
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PARAMETER["latitude_of_center",24],
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PARAMETER["longitude_of_center",-84],
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PARAMETER["false_easting",400000],
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PARAMETER["false_northing",0],
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UNIT["metre",1,
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AUTHORITY["EPSG","9001"]],
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AUTHORITY["EPSG","3086"]]
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Origin = (511700.468070655711927,435103.377123198588379)
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Pixel Size = (100.000000000000000,-100.000000000000000)
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Metadata:
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AREA_OR_POINT=Area
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Image Structure Metadata:
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INTERLEAVE=BAND
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Corner Coordinates:
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Upper Left ( 511700.468, 435103.377) ( 82d51'46.16"W, 27d55' 1.53"N)
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Lower Left ( 511700.468, 417703.377) ( 82d51'52.04"W, 27d45'37.50"N)
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Upper Right ( 528000.468, 435103.377) ( 82d41'48.81"W, 27d54'56.30"N)
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Lower Right ( 528000.468, 417703.377) ( 82d41'55.54"W, 27d45'32.28"N)
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Center ( 519850.468, 426403.377) ( 82d46'50.64"W, 27d50'16.99"N)
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Band 1 Block=163x50 Type=Byte, ColorInterp=Gray
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NoData Value=15
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"""
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import os
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import unittest
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from django.contrib.gis.gdal import HAS_GDAL
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from django.utils import six
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from django.utils._os import upath
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if HAS_GDAL:
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from django.contrib.gis.gdal import GDALRaster
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from django.contrib.gis.gdal.raster.band import GDALBand
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@unittest.skipUnless(HAS_GDAL, "GDAL is required")
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class GDALRasterTests(unittest.TestCase):
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"""
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Test a GDALRaster instance created from a file (GeoTiff).
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"""
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def setUp(self):
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self.rs_path = os.path.join(os.path.dirname(upath(__file__)),
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'data/raster.tif')
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self.rs = GDALRaster(self.rs_path)
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def test_rs_name_repr(self):
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self.assertEqual(self.rs_path, self.rs.name)
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six.assertRegex(self, repr(self.rs), "<Raster object at 0x\w+>")
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def test_rs_driver(self):
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self.assertEqual(self.rs.driver.name, 'GTiff')
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def test_rs_size(self):
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self.assertEqual(self.rs.width, 163)
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self.assertEqual(self.rs.height, 174)
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def test_rs_srs(self):
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self.assertEqual(self.rs.srs.srid, 3086)
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self.assertEqual(self.rs.srs.units, (1.0, 'metre'))
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def test_geotransform_and_friends(self):
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self.assertEqual(self.rs.geotransform,
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(511700.4680706557, 100.0, 0.0, 435103.3771231986, 0.0, -100.0))
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self.assertEqual(self.rs.origin, [511700.4680706557, 435103.3771231986])
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self.assertEqual(self.rs.origin.x, 511700.4680706557)
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self.assertEqual(self.rs.origin.y, 435103.3771231986)
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self.assertEqual(self.rs.scale, [100.0, -100.0])
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self.assertEqual(self.rs.scale.x, 100.0)
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self.assertEqual(self.rs.scale.y, -100.0)
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self.assertEqual(self.rs.skew, [0, 0])
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self.assertEqual(self.rs.skew.x, 0)
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self.assertEqual(self.rs.skew.y, 0)
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def test_rs_extent(self):
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self.assertEqual(self.rs.extent,
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(511700.4680706557, 417703.3771231986, 528000.4680706557, 435103.3771231986))
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def test_rs_bands(self):
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self.assertEqual(len(self.rs.bands), 1)
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self.assertIsInstance(self.rs.bands[0], GDALBand)
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@unittest.skipUnless(HAS_GDAL, "GDAL is required")
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class GDALBandTests(unittest.TestCase):
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def setUp(self):
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rs_path = os.path.join(os.path.dirname(upath(__file__)),
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'data/raster.tif')
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rs = GDALRaster(rs_path)
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self.band = rs.bands[0]
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def test_band_data(self):
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self.assertEqual(self.band.width, 163)
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self.assertEqual(self.band.height, 174)
|
||||
self.assertEqual(self.band.description, '')
|
||||
self.assertEqual(self.band.datatype(), 1)
|
||||
self.assertEqual(self.band.datatype(as_string=True), 'GDT_Byte')
|
||||
self.assertEqual(self.band.min, 0)
|
||||
self.assertEqual(self.band.max, 255)
|
||||
self.assertEqual(self.band.nodata_value, 15)
|
||||
|
|
@ -18,8 +18,8 @@ of vector spatial data.
|
|||
.. note::
|
||||
|
||||
Although the module is named ``gdal``, GeoDjango only supports
|
||||
some of the capabilities of OGR. Thus, none of GDAL's features
|
||||
with respect to raster (image) data are supported at this time.
|
||||
some of the capabilities of OGR. Thus, GDAL's features with respect to
|
||||
raster (image) data are minimally supported (read-only) at this time.
|
||||
|
||||
__ http://www.gdal.org/
|
||||
__ http://www.gdal.org/ogr/
|
||||
|
|
@ -1081,6 +1081,140 @@ the same coordinate transformation repeatedly on different geometries::
|
|||
... geom = feat.geom # getting clone of feature geometry
|
||||
... geom.transform(ct) # transforming
|
||||
|
||||
.. _raster-data-source-objects:
|
||||
|
||||
Raster Data Objects
|
||||
===================
|
||||
|
||||
.. versionadded:: 1.8
|
||||
|
||||
``GDALRaster``
|
||||
----------------
|
||||
|
||||
:class:`GDALRaster` is a wrapper for the GDAL raster source object that
|
||||
supports reading data from a variety of GDAL-supported geospatial file
|
||||
formats and data sources using a simple, consistent interface. Each
|
||||
data source is represented by a :class:`GDALRaster` object which contains
|
||||
one or more layers of data named bands. Each band, represented by a
|
||||
:class:`GDALBand` object, contains georeferenced image data. For exemple, an RGB
|
||||
image is represented as three bands: one for red, one for green, and one for
|
||||
blue.
|
||||
|
||||
.. class:: GDALRaster(ds_input)
|
||||
|
||||
The constructor for ``GDALRaster`` accepts a single parameter: the path of
|
||||
the file you want to read.
|
||||
|
||||
.. attribute:: name
|
||||
|
||||
The name of the source which is equivalent to the input file path.
|
||||
|
||||
.. attribute:: driver
|
||||
|
||||
The name of the GDAL driver used to handle the input file. For example,
|
||||
``GTiff`` for a ``GeoTiff`` file. See also the `GDAL Raster Formats`__
|
||||
list.
|
||||
|
||||
__ http://www.gdal.org/formats_list.html
|
||||
|
||||
.. attribute:: width
|
||||
|
||||
The width of the source in pixels (X-axis).
|
||||
|
||||
.. attribute:: height
|
||||
|
||||
The height of the source in pixels (Y-axis).
|
||||
|
||||
.. attribute:: srs
|
||||
|
||||
The spatial reference system of the source, as a
|
||||
:class:`SpatialReference` instance.
|
||||
|
||||
.. attribute:: geotransform
|
||||
|
||||
The affine transformation matrix used to georeference the source, as a
|
||||
tuple of six coefficients which map pixel/line coordinates into
|
||||
georeferenced space using the following relationship::
|
||||
|
||||
Xgeo = GT(0) + Xpixel*GT(1) + Yline*GT(2)
|
||||
Ygeo = GT(3) + Xpixel*GT(4) + Yline*GT(5)
|
||||
|
||||
The same values can be retrieved by accessing the :attr:`origin`
|
||||
(indices 0 and 3), :attr:`scale` (indices 1 and 5) and :attr:`skew`
|
||||
(indices 2 and 4) properties.
|
||||
|
||||
.. attribute:: origin
|
||||
|
||||
Coordinates of the top left origin of the raster in the spatial
|
||||
reference system of the source, as a point object with ``x`` and ``y``
|
||||
members.
|
||||
|
||||
.. attribute:: scale
|
||||
|
||||
Pixel width and height used for georeferencing the raster, as a as a
|
||||
point object with ``x`` and ``y`` members. See :attr:`geotransform`
|
||||
for more information.
|
||||
|
||||
.. attribute:: skew
|
||||
|
||||
Skew coefficients used to georeference the raster, as a point object
|
||||
with ``x`` and ``y`` members. In case of north up images, these
|
||||
coefficients are both ``0``.
|
||||
|
||||
.. attribute:: extent
|
||||
|
||||
Extent (boundary values) of the raster source, as a 4-tuple
|
||||
``(xmin, ymin, xmax, ymax)`` in the spatial reference system of the
|
||||
source.
|
||||
|
||||
.. attribute:: bands
|
||||
|
||||
List of all bands of the source, as :class:`GDALBand` instances.
|
||||
|
||||
``GDALBand``
|
||||
------------
|
||||
|
||||
.. class:: GDALBand
|
||||
|
||||
``GDALBand`` instances are not created explicitely, but rather obtained
|
||||
from a :class:`GDALRaster` object, through its :attr:`~GDALRaster.bands`
|
||||
attribute.
|
||||
|
||||
.. attribute:: description
|
||||
|
||||
The name or description of the band, if any.
|
||||
|
||||
.. attribute:: width
|
||||
|
||||
The width of the band in pixels (X-axis).
|
||||
|
||||
.. attribute:: height
|
||||
|
||||
The height of the band in pixels (Y-axis).
|
||||
|
||||
.. attribute:: min
|
||||
|
||||
The minimum pixel value of the band (excluding the "no data" value).
|
||||
|
||||
.. attribute:: max
|
||||
|
||||
The maximum pixel value of the band (excluding the "no data" value).
|
||||
|
||||
.. attribute:: nodata_value
|
||||
|
||||
The "no data" value for a band is generally a special marker value used
|
||||
to mark pixels that are not valid data. Such pixels should generally not
|
||||
be displayed, nor contribute to analysis operations.
|
||||
|
||||
.. method:: datatype([as_string=False])
|
||||
|
||||
The data type contained in the band, as an integer constant between 0
|
||||
(Unknown) and 11. If ``as_string`` is ``True``, the data type is
|
||||
returned as a string with the following possible values:
|
||||
``GDT_Unknown``, ``GDT_Byte``, ``GDT_UInt16``, ``GDT_Int16``,
|
||||
``GDT_UInt32``, ``GDT_Int32``, ``GDT_Float32``, ``GDT_Float64``,
|
||||
``GDT_CInt16``, ``GDT_CInt32``, ``GDT_CFloat32``, and ``GDT_CFloat64``.
|
||||
|
||||
Settings
|
||||
========
|
||||
|
||||
|
|
|
|||
|
|
@ -166,6 +166,9 @@ Minor features
|
|||
``SELECT InitSpatialMetaData`` initialization commands are now automatically
|
||||
run by :djadmin:`migrate`.
|
||||
|
||||
* The GDAL interface now supports retrieving properties of
|
||||
:ref:`raster (image) data file <raster-data-source-objects>`.
|
||||
|
||||
* Compatibility shims for ``SpatialRefSys`` and ``GeometryColumns`` changed in
|
||||
Django 1.2 have been removed.
|
||||
|
||||
|
|
|
|||
Loading…
Reference in New Issue