def testSingleBandPseudoColorRenderer_Exact(self):
# get min and max of the band to renderer
bandNo = 3
stats = self.raster_layer.dataProvider().bandStatistics(bandNo, QgsRasterBandStats.Min | QgsRasterBandStats.Max)
minValue = stats.minimumValue
maxValue = stats.maximumValue
# create shader for the renderer
shader = QgsRasterShader(minValue, maxValue)
colorRampShaderFcn = QgsColorRampShader(minValue, maxValue)
colorRampShaderFcn.setColorRampType(QgsColorRampShader.Exact)
colorRampShaderFcn.setClassificationMode(QgsColorRampShader.Continuous)
colorRampShaderFcn.setClip(True)
items = []
for index in range(10):
items.append(QgsColorRampShader.ColorRampItem(index, QColor('#{0:02d}{0:02d}{0:02d}'.format(index)),
"{}".format(index)))
colorRampShaderFcn.setColorRampItemList(items)
shader.setRasterShaderFunction(colorRampShaderFcn)
# create instance to test
rasterRenderer = QgsSingleBandPseudoColorRenderer(self.raster_layer.dataProvider(), bandNo, shader)
self.raster_layer.setRenderer(rasterRenderer)
# do test
dom, root = self.rendererToSld(self.raster_layer.renderer())
self.assertNoOpacity(root)
self.assertChannelBand(root, 'sld:GrayChannel', '{}'.format(bandNo))
# check ColorMapEntry classes
colorMap = root.elementsByTagName('sld:ColorMap')
colorMap = colorMap.item(0).toElement()
self.assertFalse(colorMap.isNull())
self.assertEqual(colorMap.attribute('type'), 'values')
self.assertFalse(colorMap.hasAttribute('extendend'))
colorMapEntries = colorMap.elementsByTagName('sld:ColorMapEntry')
self.assertEqual(colorMapEntries.count(), 10)
for index in range(colorMapEntries.count()):
colorMapEntry = colorMapEntries.at(index).toElement()
self.assertEqual(colorMapEntry.attribute('quantity'), '{}'.format(index))
self.assertEqual(colorMapEntry.attribute('label'), '{}'.format(index))
self.assertEqual(colorMapEntry.attribute('opacity'), '')
self.assertEqual(colorMapEntry.attribute('color'), '#{0:02d}{0:02d}{0:02d}'.format(index))
# add check that is set ColoMap extended="true" if colormap is bigger that 255 entries
# !NOTE! can't reuse previous shader => segmentation fault
shader = QgsRasterShader(minValue, maxValue)
colorRampShaderFcn = QgsColorRampShader(minValue, maxValue)
colorRampShaderFcn.setColorRampType(QgsColorRampShader.Exact)
colorRampShaderFcn.setClassificationMode(QgsColorRampShader.Continuous)
colorRampShaderFcn.setClip(True)
items = []
for index in range(255):
items.append(
QgsColorRampShader.ColorRampItem(index, QColor.fromHsv(index, 255, 255, 255), "{}".format(index)))
colorRampShaderFcn.setColorRampItemList(items)
shader.setRasterShaderFunction(colorRampShaderFcn)
# create instance to test
rasterRenderer = QgsSingleBandPseudoColorRenderer(self.raster_layer.dataProvider(), bandNo, shader)
def testSingleBandPseudoColorRenderer_Exact(self):
# get min and max of the band to renderer
bandNo = 3
stats = self.raster_layer.dataProvider().bandStatistics(bandNo, QgsRasterBandStats.Min | QgsRasterBandStats.Max)
minValue = stats.minimumValue
maxValue = stats.maximumValue
# create shader for the renderer
shader = QgsRasterShader(minValue, maxValue)
colorRampShaderFcn = QgsColorRampShader(minValue, maxValue)
colorRampShaderFcn.setColorRampType(QgsColorRampShader.Exact)
colorRampShaderFcn.setClassificationMode(QgsColorRampShader.Continuous)
colorRampShaderFcn.setClip(True)
items = []
for index in range(10):
items.append(QgsColorRampShader.ColorRampItem(index, QColor('#{0:02d}{0:02d}{0:02d}'.format(index)), "{}".format(index)))
colorRampShaderFcn.setColorRampItemList(items)
shader.setRasterShaderFunction(colorRampShaderFcn)
# create instance to test
rasterRenderer = QgsSingleBandPseudoColorRenderer(self.raster_layer.dataProvider(), bandNo, shader)
self.raster_layer.setRenderer(rasterRenderer)
# do test
dom, root = self.rendererToSld(self.raster_layer.renderer())
self.assertNoOpacity(root)
self.assertChannelBand(root, 'sld:GrayChannel', '{}'.format(bandNo))
# check ColorMapEntry classes
colorMap = root.elementsByTagName('sld:ColorMap')
colorMap = colorMap.item(0).toElement()
self.assertFalse(colorMap.isNull())
self.assertEqual(colorMap.attribute('type'), 'values')
self.assertFalse(colorMap.hasAttribute('extendend'))
colorMapEntries = colorMap.elementsByTagName('sld:ColorMapEntry')
self.assertEqual(colorMapEntries.count(), 10)
for index in range(colorMapEntries.count()):
colorMapEntry = colorMapEntries.at(index).toElement()
self.assertEqual(colorMapEntry.attribute('quantity'), '{}'.format(index))
self.assertEqual(colorMapEntry.attribute('label'), '{}'.format(index))
self.assertEqual(colorMapEntry.attribute('opacity'), '')
self.assertEqual(colorMapEntry.attribute('color'), '#{0:02d}{0:02d}{0:02d}'.format(index))
# add check that is set ColoMap extended="true" if colormap is bigger that 255 entries
# !NOTE! can't reuse previous shader => segmentation fault
shader = QgsRasterShader(minValue, maxValue)
colorRampShaderFcn = QgsColorRampShader(minValue, maxValue)
colorRampShaderFcn.setColorRampType(QgsColorRampShader.Exact)
colorRampShaderFcn.setClassificationMode(QgsColorRampShader.Continuous)
colorRampShaderFcn.setClip(True)
items = []
for index in range(255):
items.append(QgsColorRampShader.ColorRampItem(index, QColor.fromHsv(index, 255, 255, 255), "{}".format(index)))
colorRampShaderFcn.setColorRampItemList(items)
shader.setRasterShaderFunction(colorRampShaderFcn)
# create instance to test
rasterRenderer = QgsSingleBandPseudoColorRenderer(self.raster_layer.dataProvider(), bandNo, shader)
def rat_classify(raster_layer, band, rat, criteria, ramp=None, feedback=QgsRasterBlockFeedback()) -> list:
"""Classify a raster.
Note: cannot use a custom shader function QgsColorRampShader subclass because it's lost in
the clone stage of the renderer.
:param raster_layer: the raster layer to classify
:type raster_layer: QgsRasterLayer
:param band: band number (1-based)
:type band: int
:param rat: the RAT data
:type rat: dict
:param criteria: key of the RAT to be used for labels
:type criteria: str
:param ramp: optional color ramp, defaults to QgsRandomColorRamp()
:type ramp: QgsColorRamp, optional
:param feedback: QGIS feedback object, defaults to QgsRasterBlockFeedback()
:type feedback: QgsRasterBlockFeedback, optional
:return: unique row indexes for legend items (1-based)
:rtype: list
"""
has_color = rat.has_color
labels = rat.data[criteria]
label_colors = {}
unique_indexes = []
# QGIS >= 3.18 for first element label
if Qgis.QGIS_VERSION_INT >= 31800:
base_legend_row_index = 1
else:
base_legend_row_index = 0
if rat.thematic_type == gdal.GRTT_THEMATIC:
# Use paletted
rat_log('Using paletted renderer')
value_column_name = rat.field_name(gdal.GFU_MinMax)
values = rat.data[value_column_name]
is_integer = isinstance(values[0], int)
if ramp is None:
ramp = QgsRandomColorRamp()
classes = QgsPalettedRasterRenderer.classDataFromRaster(
raster_layer.dataProvider(), band, ramp, feedback)
row_index = base_legend_row_index
for klass in classes:
value = int(klass.value) if is_integer else klass.value
try:
index = values.index(value)
except ValueError: # NODATA
rat_log(
f'Value {value} not found in RAT, assuming NODATA', Qgis.Warning)
data_provider = raster_layer.dataProvider()
if not data_provider.userNoDataValuesContains(band, value):
nodata = data_provider.userNoDataValues(band)
nodata_value = QgsRasterRange(value, value)
nodata.append(nodata_value)
data_provider.setUserNoDataValue(band, nodata)
continue
klass.label = str(labels[index])
if klass.label not in label_colors:
unique_indexes.append(row_index)
if has_color:
label_colors[klass.label] = rat.data[RAT_COLOR_HEADER_NAME][index]
else:
label_colors[klass.label] = klass.color
klass.color = label_colors[klass.label]
row_index += 1
renderer = QgsPalettedRasterRenderer(
raster_layer.dataProvider(), band, classes)
else: # ranges
rat_log('Using singleband pseudocolor renderer')
min_value_column = rat.field_name(gdal.GFU_Min)
max_value_column = rat.field_name(gdal.GFU_Max)
# Collect unique values and colors from criteria
row_index = base_legend_row_index
unique_labels = []
for index in range(len(labels)):
label = labels[index]
if label not in unique_labels:
unique_labels.append(label)
unique_indexes.append(row_index)
# Collect color
if has_color:
label_colors[label] = rat.data[RAT_COLOR_HEADER_NAME][index]
row_index += 1
# Assign colors from random ramp
if not has_color:
ramp = QgsRandomColorRamp()
ramp.setTotalColorCount(len(unique_labels))
i = 0
for index in unique_indexes:
label_colors[labels[index]] = ramp.color(ramp.value(i))
i += 1
# Create values for the ramp
# Collect colors for all classes
colors = []
for label in labels:
colors.append(label_colors[label])
ramp = QgsPresetSchemeColorRamp(colors)
minValue = min(rat.data[min_value_column])
maxValue = max(rat.data[max_value_column])
assert minValue < maxValue, "Min Value must be lower than Max Value"
shader = QgsRasterShader(minValue, maxValue)
colorRampShaderFcn = QgsColorRampShader(
minValue, maxValue, ramp)
colorRampShaderFcn.setClip(True)
colorRampShaderFcn.setColorRampType(QgsColorRampShader.Discrete)
items = []
row = 0
for label in labels:
items.append(QgsColorRampShader.ColorRampItem(
rat.data[max_value_column][row], label_colors[label], label))
row += 1
colorRampShaderFcn.setColorRampItemList(items)
try: # for older QGIS
colorRampShaderFcn.legendSettings().setUseContinuousLegend(False)
except AttributeError:
rat_log(
'QgsColorRampShader.legendSettings().setUseContinuousLegend() is not supported on ths QGIS version.', Qgis.Warning)
shader.setRasterShaderFunction(colorRampShaderFcn)
renderer = QgsSingleBandPseudoColorRenderer(
raster_layer.dataProvider(), band, shader)
raster_layer.setRenderer(renderer)
raster_layer.triggerRepaint()
return unique_indexes
