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103 lines
3.4 KiB
Python
103 lines
3.4 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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import struct
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import numpy
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from osgeo import gdal
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from osgeo.gdalconst import *
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from osgeo import osr
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from PyQt4.QtCore import *
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from qgis.core import *
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def scanraster(layer, progress):
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filename = unicode(layer.source())
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dataset = gdal.Open(filename, GA_ReadOnly)
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band = dataset.GetRasterBand(1)
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nodata = band.GetNoDataValue()
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for y in xrange(band.YSize):
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progress.setPercentage(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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values = struct.unpack('f' * band.XSize, scanline)
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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)[1], 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:
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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):
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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.ones(shape=(self.ny, self.nx), dtype=numpy.float32)
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self.matrix[:] = 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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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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format = 'GTiff'
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driver = gdal.GetDriverByName(format)
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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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dst_ds.SetGeoTransform([self.minx, self.cellsize, 0,
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self.maxy, self.cellsize, 0])
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dst_ds.GetRasterBand(1).WriteArray(self.matrix)
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dst_ds = None
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