2024-11-29 15:38:02 +01:00

69 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)