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[processing] add Extract raster values to shapefile algorithm
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python/plugins/processing/script/scripts/Extract_raster_values_to_shapefile.py
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##[Example scripts]=group | ||
##Input_raster=raster | ||
##Input_vector=vector | ||
##Transform_vector_to_raster_CRS=boolean | ||
##Output_layer=output vector | ||
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import os | ||
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from osgeo import gdal, ogr, osr | ||
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from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException | ||
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from processing.algs import QGISUtils as utils | ||
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raster = gdal.Open(Input_raster) | ||
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rasterBaseName = os.path.splitext(os.path.basename(Input_raster))[0] | ||
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bandCount = raster.RasterCount | ||
rasterXSize = raster.RasterXSize | ||
rasterYSize = raster.RasterYSize | ||
geoTransform = raster.GetGeoTransform() | ||
rasterCRS = osr.SpatialReference() | ||
rasterCRS.ImportFromWkt(raster.GetProjectionRef()) | ||
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vector = ogr.Open(Input_vector, False) | ||
layer = vector.GetLayer(0) | ||
featureCount = layer.GetFeatureCount() | ||
if featureCount == 0: | ||
raise GeoAlgorithmExecutionException("There are no features in input vector.") | ||
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vectorCRS = layer.GetSpatialRef() | ||
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drv = ogr.GetDriverByName("ESRI Shapefile") | ||
if drv is None: | ||
raise GeoAlgorithmExecutionException("'ESRI Shapefile' driver is not available.") | ||
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outputDataset = drv.CreateDataSource(Output_layer) | ||
if outputDataset is None: | ||
raise GeoAlgorithmExecutionException("Creation of output file failed.") | ||
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outputLayer = outputDataset.CreateLayer(str(os.path.splitext(os.path.basename(Output_layer))[0]), vectorCRS, ogr.wkbPoint) | ||
if outputLayer is None: | ||
raise GeoAlgorithmExecutionException("Layer creation failed.") | ||
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featureDefn = layer.GetLayerDefn() | ||
for i in xrange(featureDefn.GetFieldCount()): | ||
fieldDefn = featureDefn.GetFieldDefn(i) | ||
if outputLayer.CreateField(fieldDefn) != 0: | ||
raise GeoAlgorithmExecutionException("Can't create field '%s'." % fieldDefn.GetNameRef()) | ||
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columnName = str(rasterBaseName[:8]) | ||
for i in xrange(bandCount): | ||
fieldDefn = ogr.FieldDefn(columnName + "_" + str(i + 1), ogr.OFTReal) | ||
fieldDefn.SetWidth(18) | ||
fieldDefn.SetPrecision(8) | ||
if outputLayer.CreateField(fieldDefn) != 0: | ||
raise GeoAlgorithmExecutionException("Can't create field '%s'." % fieldDefn.GetNameRef()) | ||
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outputFeature = ogr.Feature(outputLayer.GetLayerDefn()) | ||
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current = 0 | ||
total = bandCount + featureCount * bandCount + featureCount | ||
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layer.ResetReading() | ||
feature = layer.GetNextFeature() | ||
while feature is not None: | ||
current += 1 | ||
progress.setPercentage(int(current * total)) | ||
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outputFeature.SetFrom(feature) | ||
if outputLayer.CreateFeature(outputFeature) != 0: | ||
raise GeoAlgorithmExecutionException("Failed to add feature.") | ||
feature = layer.GetNextFeature() | ||
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vector.Destroy() | ||
outputFeature.Destroy() | ||
outputDataset.Destroy() | ||
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vector = ogr.Open(Output_layer, True) | ||
layer = vector.GetLayer(0) | ||
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if Transform_vector_to_raster_CRS: | ||
coordTransform = osr.CoordinateTransformation(vectorCRS, rasterCRS) | ||
if coordTransform is None: | ||
raise GeoAlgorithmExecutionException("Error while creating coordinate transformation.") | ||
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for i in xrange(bandCount): | ||
current += 1 | ||
progress.setPercentage(int(current * total)) | ||
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rasterBand = raster.GetRasterBand(i + 1) | ||
data = rasterBand.ReadAsArray() | ||
layer.ResetReading() | ||
feature = layer.GetNextFeature() | ||
while feature is not None: | ||
current += 1 | ||
progress.setPercentage(int(current * total)) | ||
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geometry = feature.GetGeometryRef() | ||
x = geometry.GetX() | ||
y = geometry.GetY() | ||
if Transform_vector_to_raster_CRS: | ||
pnt = coordTransform.TransformPoint(x, y, 0) | ||
x = pnt[0] | ||
y = pnt[1] | ||
rX, rY = utils.mapToPixel(x, y, geoTransform) | ||
if rX > rasterXSize or rY > rasterYSize: | ||
feature = layer.GetNextFeature() | ||
continue | ||
value = data[rY, rX] | ||
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feature.SetField(columnName + '_' + str(i + 1), float(value)) | ||
if layer.SetFeature(feature) != 0: | ||
raise GeoAlgorithmExecutionException("Failed to update feature.") | ||
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feature = layer.GetNextFeature() | ||
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rasterBand = None | ||
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raster = None | ||
vector.Destroy() |