71 lines
2.7 KiB
Python

"""
***************************************************************************
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
gdal.UseExceptions()
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)