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- """
- ***************************************************************************
- raster.py
- ---------------------
- Date : February 2013
- Copyright : (C) 2013 by Victor Olaya and Alexander Bruy
- Email : volayaf at gmail dot com
- ***************************************************************************
- * *
- * 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 2 of the License, or *
- * (at your option) any later version. *
- * *
- ***************************************************************************
- """
- __author__ = 'Victor Olaya and Alexander Bruy'
- __date__ = 'February 2013'
- __copyright__ = '(C) 2013, Victor Olaya and Alexander Bruy'
- import struct
- from osgeo import gdal
- from qgis.core import QgsProcessingException
- def scanraster(layer, feedback, band_number=1):
- filename = str(layer.source())
- dataset = gdal.Open(filename, gdal.GA_ReadOnly)
- band = dataset.GetRasterBand(band_number)
- nodata = band.GetNoDataValue()
- bandtype = gdal.GetDataTypeName(band.DataType)
- for y in range(band.YSize):
- feedback.setProgress(y / float(band.YSize) * 100)
- scanline = band.ReadRaster(0, y, band.XSize, 1, band.XSize, 1,
- band.DataType)
- if bandtype == 'Byte':
- values = struct.unpack('B' * band.XSize, scanline)
- elif bandtype == 'Int16':
- values = struct.unpack('h' * band.XSize, scanline)
- elif bandtype == 'UInt16':
- values = struct.unpack('H' * band.XSize, scanline)
- elif bandtype == 'Int32':
- values = struct.unpack('i' * band.XSize, scanline)
- elif bandtype == 'UInt32':
- values = struct.unpack('I' * band.XSize, scanline)
- elif bandtype == 'Float32':
- values = struct.unpack('f' * band.XSize, scanline)
- elif bandtype == 'Float64':
- values = struct.unpack('d' * band.XSize, scanline)
- else:
- raise QgsProcessingException('Raster format not supported')
- for value in values:
- if value == nodata:
- value = None
- yield value
- def mapToPixel(mX, mY, geoTransform):
- (pX, pY) = gdal.ApplyGeoTransform(
- gdal.InvGeoTransform(geoTransform), mX, mY)
- return (int(pX), int(pY))
- def pixelToMap(pX, pY, geoTransform):
- return gdal.ApplyGeoTransform(geoTransform, pX + 0.5, pY + 0.5)
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