Merge pull request #4948 from alexbruy/processing-raster

[processing] restore and improve some raster algorithms

Author: alexbruy

python/core/raster/qgsrasterfilewriter.sip

@@ -156,6 +156,15 @@ class QgsRasterFileWriter
  :rtype: list of str
 %End
 
+    static QString driverForExtension( const QString &extension );
+%Docstring
+ Returns the GDAL driver name for a specified file ``extension``. E.g. the
+ driver name for the ".tif" extension is "GTiff".
+ If no suitable drivers are found then an empty string is returned.
+.. versionadded:: 3.0
+ :rtype: str
+%End
+
 };
 
 /************************************************************************

python/plugins/processing/algs/help/qgis.yaml

@@ -467,9 +467,7 @@ qgis:rasterlayerhistogram: >
   The raster layer must have a single band.
 
 qgis:rasterlayerstatistics: >
-  This algorithm computes basic statistics from the values in a raster layer.
-
-  The raster layer must have a single band.
+  This algorithm computes basic statistics from the values in a given band of the raster layer.
 
 qgis:refactorfields: >
   This algorithm allows editing the structure of the attributes table of a vector layer. Fields can be modified in their type and name, using a fields mapping.

python/plugins/processing/algs/qgis/Aspect.py

@@ -30,11 +30,11 @@
 from qgis.PyQt.QtGui import QIcon
 
 from qgis.analysis import QgsAspectFilter
-from qgis.core import (QgsProcessingParameterRasterLayer,
+from qgis.core import (QgsRasterFileWriter,
+                       QgsProcessingParameterRasterLayer,
                        QgsProcessingParameterNumber,
                        QgsProcessingParameterRasterDestination)
 from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
-from processing.tools import raster
 from processing.tools.dataobjects import exportRasterLayer
 
 pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]
@@ -75,7 +75,7 @@ def processAlgorithm(self, parameters, context, feedback):
 
         outputFile = self.parameterAsOutputLayer(parameters, self.OUTPUT, context)
 
-        outputFormat = raster.formatShortNameFromFileName(outputFile)
+        outputFormat = QgsRasterFileWriter.driverForExtension(os.path.splitext(outputFile)[1])
 
         aspect = QgsAspectFilter(inputFile, outputFile, outputFormat)
         aspect.setZFactor(zFactor)

python/plugins/processing/algs/qgis/CreateConstantRaster.py

@@ -25,20 +25,27 @@
 
 __revision__ = '$Format:%H$'
 
-from osgeo import gdal
-
-from qgis.core import (QgsProcessingParameterRasterLayer,
+import os
+import math
+import struct
+
+from qgis.core import (Qgis,
+                       QgsRasterBlock,
+                       QgsRasterFileWriter,
+                       QgsProcessingParameterExtent,
                        QgsProcessingParameterNumber,
+                       QgsProcessingParameterCrs,
                        QgsProcessingParameterRasterDestination)
 from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
-from processing.tools.raster import RasterWriter
 
 
 class CreateConstantRaster(QgisAlgorithm):
 
-    INPUT = 'INPUT'
-    OUTPUT = 'OUTPUT'
+    EXTENT = 'EXTENT'
+    TARGET_CRS = 'TARGET_CRS'
+    PIXEL_SIZE = 'PIXEL_SIZE'
     NUMBER = 'NUMBER'
+    OUTPUT = 'OUTPUT'
 
     def group(self):
         return self.tr('Raster tools')
@@ -47,10 +54,18 @@ def __init__(self):
         super().__init__()
 
     def initAlgorithm(self, config=None):
-        self.addParameter(QgsProcessingParameterRasterLayer(self.INPUT,
-                                                            self.tr('Reference layer')))
+        self.addParameter(QgsProcessingParameterExtent(self.EXTENT,
+                                                       self.tr('Desired extent')))
+        self.addParameter(QgsProcessingParameterCrs(self.TARGET_CRS,
+                                                    self.tr('Target CRS'),
+                                                    'ProjectCrs'))
+        self.addParameter(QgsProcessingParameterNumber(self.PIXEL_SIZE,
+                                                       self.tr('Pixel size'),
+                                                       QgsProcessingParameterNumber.Double,
+                                                       0.1, False, 0.01, 999))
         self.addParameter(QgsProcessingParameterNumber(self.NUMBER,
-                                                       self.tr('Constant value'), QgsProcessingParameterNumber.Double,
+                                                       self.tr('Constant value'),
+                                                       QgsProcessingParameterNumber.Double,
                                                        defaultValue=1))
         self.addParameter(QgsProcessingParameterRasterDestination(self.OUTPUT, self.tr('Constant')))
 
@@ -61,28 +76,35 @@ def displayName(self):
         return self.tr('Create constant raster layer')
 
     def processAlgorithm(self, parameters, context, feedback):
-        layer = self.parameterAsRasterLayer(parameters, self.INPUT, context)
+        extent = self.parameterAsExtent(parameters, self.EXTENT, context)
+        crs = self.parameterAsCrs(parameters, self.TARGET_CRS, context)
         value = self.parameterAsDouble(parameters, self.NUMBER, context)
+        pixelSize = self.parameterAsDouble(parameters, self.PIXEL_SIZE, context)
 
         outputFile = self.parameterAsOutputLayer(parameters, self.OUTPUT, context)
+        outputFormat = QgsRasterFileWriter.driverForExtension(os.path.splitext(outputFile)[1])
+
+        rows = max([math.ceil(extent.height() / pixelSize) + 1, 1.0])
+        cols = max([math.ceil(extent.width() / pixelSize) + 1, 1.0])
+
+        writer = QgsRasterFileWriter(outputFile)
+        writer.setOutputProviderKey('gdal')
+        writer.setOutputFormat(outputFormat)
+        provider = writer.createOneBandRaster(Qgis.Float32, cols, rows, extent, crs)
+        provider.setNoDataValue(1, -9999)
+
+        data = [value] * cols
+        block = QgsRasterBlock(Qgis.Float32, cols, 1)
+        block.setData(struct.pack('{}f'.format(len(data)), *data))
+
+        total = 100.0 / rows if rows else 0
+        for i in range(rows):
+            if feedback.isCanceled():
+                break
+
+            provider.writeBlock(block, 1, 0, i)
+            feedback.setProgress(int(i * rows))
 
-        raster = gdal.Open(layer.source(), gdal.GA_ReadOnly)
-        geoTransform = raster.GetGeoTransform()
-
-        cellsize = (layer.extent().xMaximum() - layer.extent().xMinimum()) \
-            / layer.width()
-
-        w = RasterWriter(outputFile,
-                         layer.extent().xMinimum(),
-                         layer.extent().yMinimum(),
-                         layer.extent().xMaximum(),
-                         layer.extent().yMaximum(),
-                         cellsize,
-                         1,
-                         layer.crs(),
-                         geoTransform
-                         )
-        w.matrix.fill(value)
-        w.close()
+        provider.setEditable(False)
 
         return {self.OUTPUT: outputFile}

python/plugins/processing/algs/qgis/Heatmap.py

@@ -31,6 +31,7 @@
 from qgis.PyQt.QtGui import QIcon
 
 from qgis.core import (QgsFeatureRequest,
+                       QgsRasterFileWriter,
                        QgsProcessing,
                        QgsProcessingException,
                        QgsProcessingParameterFeatureSource,
@@ -43,7 +44,6 @@
 from qgis.analysis import QgsKernelDensityEstimation
 
 from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
-from processing.tools import raster
 
 pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]
 
@@ -175,7 +175,7 @@ def processAlgorithm(self, parameters, context, feedback):
         decay = self.parameterAsDouble(parameters, self.DECAY, context)
         output_values = self.parameterAsEnum(parameters, self.OUTPUT_VALUE, context)
         outputFile = self.parameterAsOutputLayer(parameters, self.OUTPUT, context)
-        output_format = raster.formatShortNameFromFileName(outputFile)
+        output_format = QgsRasterFileWriter.driverForExtension(os.path.splitext(outputFile)[1])
         weight_field = self.parameterAsString(parameters, self.WEIGHT_FIELD, context)
         radius_field = self.parameterAsString(parameters, self.RADIUS_FIELD, context)
 

python/plugins/processing/algs/qgis/Hillshade.py

@@ -30,11 +30,11 @@
 from qgis.PyQt.QtGui import QIcon
 
 from qgis.analysis import QgsHillshadeFilter
-from qgis.core import (QgsProcessingParameterRasterLayer,
+from qgis.core import (QgsRasterFileWriter,
+                       QgsProcessingParameterRasterLayer,
                        QgsProcessingParameterNumber,
                        QgsProcessingParameterRasterDestination)
 from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
-from processing.tools import raster
 from processing.tools.dataobjects import exportRasterLayer
 
 pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]
@@ -84,8 +84,7 @@ def processAlgorithm(self, parameters, context, feedback):
         vAngle = self.parameterAsDouble(parameters, self.V_ANGLE, context)
 
         outputFile = self.parameterAsOutputLayer(parameters, self.OUTPUT, context)
-
-        outputFormat = raster.formatShortNameFromFileName(outputFile)
+        outputFormat = QgsRasterFileWriter.driverForExtension(os.path.splitext(outputFile)[1])
 
         hillshade = QgsHillshadeFilter(inputFile, outputFile, outputFormat, azimuth, vAngle)
         hillshade.setZFactor(zFactor)

python/plugins/processing/algs/qgis/QGISAlgorithmProvider.py

@@ -99,6 +99,7 @@
 from .RandomPointsExtent import RandomPointsExtent
 from .RandomPointsLayer import RandomPointsLayer
 from .RandomPointsPolygons import RandomPointsPolygons
+from .RasterLayerStatistics import RasterLayerStatistics
 from .RegularPoints import RegularPoints
 from .ReverseLineDirection import ReverseLineDirection
 from .Ruggedness import Ruggedness
@@ -144,7 +145,6 @@
 # from .HubDistanceLines import HubDistanceLines
 # from .HubLines import HubLines
 # from .GeometryConvert import GeometryConvert
-# from .RasterLayerStatistics import RasterLayerStatistics
 # from .StatisticsByCategories import StatisticsByCategories
 # from .FieldsCalculator import FieldsCalculator
 # from .FieldPyculator import FieldsPyculator
@@ -270,6 +270,7 @@ def getAlgs(self):
                 RandomPointsExtent(),
                 RandomPointsLayer(),
                 RandomPointsPolygons(),
+                RasterLayerStatistics(),
                 RegularPoints(),
                 ReverseLineDirection(),
                 Ruggedness(),