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159 lines
5.2 KiB
Python
159 lines
5.2 KiB
Python
# -*- coding: utf-8 -*-
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"""
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***************************************************************************
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raster.py
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---------------------
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Date : February 2013
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Copyright : (C) 2013 by Victor Olaya and Alexander Bruy
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Email : volayaf at gmail dot com
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***************************************************************************
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* *
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* This program is free software; you can redistribute it and/or modify *
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* it under the terms of the GNU General Public License as published by *
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* the Free Software Foundation; either version 2 of the License, or *
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* (at your option) any later version. *
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* *
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***************************************************************************
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"""
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__author__ = 'Victor Olaya and Alexander Bruy'
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__date__ = 'February 2013'
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__copyright__ = '(C) 2013, Victor Olaya and Alexander Bruy'
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# This will get replaced with a git SHA1 when you do a git archive
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__revision__ = '$Format:%H$'
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from builtins import str
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from builtins import range
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from builtins import object
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import os
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import struct
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import numpy
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from osgeo import gdal
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from qgis.core import QgsProcessingException
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RASTER_EXTENSION_MAP = None
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def initGdalData():
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global RASTER_EXTENSION_MAP
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if RASTER_EXTENSION_MAP is not None:
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return
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if gdal.GetDriverCount() == 0:
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gdal.AllRegister()
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RASTER_EXTENSION_MAP = dict()
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for i in range(gdal.GetDriverCount()):
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driver = gdal.GetDriver(i)
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if driver is None:
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continue
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md = driver.GetMetadata()
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if gdal.DCAP_CREATE in md and md[gdal.DCAP_CREATE].lower() == 'yes':
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ext = md[gdal.DMD_EXTENSION] if gdal.DMD_EXTENSION in md else None
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if ext is not None and ext != '':
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RASTER_EXTENSION_MAP[driver.ShortName] = ext
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def formatShortNameFromFileName(fileName):
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initGdalData()
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ext = os.path.splitext(fileName)[1][1:]
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for k, v in RASTER_EXTENSION_MAP.items():
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if ext == v:
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return k
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return 'GTiff'
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def scanraster(layer, feedback):
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filename = str(layer.source())
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dataset = gdal.Open(filename, gdal.GA_ReadOnly)
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band = dataset.GetRasterBand(1)
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nodata = band.GetNoDataValue()
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bandtype = gdal.GetDataTypeName(band.DataType)
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for y in range(band.YSize):
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feedback.setProgress(y / float(band.YSize) * 100)
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scanline = band.ReadRaster(0, y, band.XSize, 1, band.XSize, 1,
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band.DataType)
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if bandtype == 'Byte':
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values = struct.unpack('B' * band.XSize, scanline)
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elif bandtype == 'Int16':
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values = struct.unpack('h' * band.XSize, scanline)
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elif bandtype == 'UInt16':
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values = struct.unpack('H' * band.XSize, scanline)
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elif bandtype == 'Int32':
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values = struct.unpack('i' * band.XSize, scanline)
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elif bandtype == 'UInt32':
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values = struct.unpack('I' * band.XSize, scanline)
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elif bandtype == 'Float32':
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values = struct.unpack('f' * band.XSize, scanline)
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elif bandtype == 'Float64':
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values = struct.unpack('d' * band.XSize, scanline)
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else:
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raise QgsProcessingException('Raster format not supported')
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for value in values:
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if value == nodata:
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value = None
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yield value
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def mapToPixel(mX, mY, geoTransform):
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(pX, pY) = gdal.ApplyGeoTransform(
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gdal.InvGeoTransform(geoTransform), mX, mY)
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return (int(pX), int(pY))
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def pixelToMap(pX, pY, geoTransform):
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return gdal.ApplyGeoTransform(geoTransform, pX + 0.5, pY + 0.5)
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class RasterWriter(object):
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NODATA = -99999.0
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def __init__(self, fileName, minx, miny, maxx, maxy, cellsize,
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nbands, crs, geotransform=None):
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self.fileName = fileName
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self.nx = int((maxx - minx) / float(cellsize))
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self.ny = int((maxy - miny) / float(cellsize))
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self.nbands = nbands
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self.matrix = numpy.empty(shape=(self.ny, self.nx), dtype=numpy.float32)
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self.matrix.fill(self.NODATA)
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self.cellsize = cellsize
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self.crs = crs
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self.minx = minx
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self.maxy = maxy
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self.geotransform = geotransform
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def setValue(self, value, x, y, band=0):
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try:
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self.matrix[y, x] = value
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except IndexError:
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pass
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def getValue(self, x, y, band=0):
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try:
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return self.matrix[y, x]
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except IndexError:
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return self.NODATA
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def close(self):
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fmt = 'GTiff'
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driver = gdal.GetDriverByName(fmt)
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dst_ds = driver.Create(self.fileName, self.nx, self.ny, 1,
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gdal.GDT_Float32)
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dst_ds.SetProjection(str(self.crs.toWkt()))
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if self.geotransform is None:
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dst_ds.SetGeoTransform([self.minx, self.cellsize, 0,
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self.maxy, self.cellsize, 0])
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else:
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dst_ds.SetGeoTransform(self.geotransform)
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dst_ds.GetRasterBand(1).WriteArray(self.matrix)
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dst_ds = None
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