def postProcessAlgorithm(self, context, feedback):
output = QgsProcessingUtils.mapLayerFromString(self.output_model,
context)
provider = output.dataProvider()
stats = provider.bandStatistics(1, QgsRasterBandStats.All,
output.extent(), 0)
mean, sd = stats.mean, stats.stdDev
rnd = QgsSingleBandGrayRenderer(provider, 1)
ce = QgsContrastEnhancement(provider.dataType(1))
ce.setContrastEnhancementAlgorithm(
QgsContrastEnhancement.StretchToMinimumMaximum)
ce.setMinimumValue(mean - 3 * sd)
ce.setMaximumValue(min(1, mean + 2 * sd))
rnd.setContrastEnhancement(ce)
output.setRenderer(rnd)
output.triggerRepaint()
return {self.OUTPUT: self.output_model}
def update_pc_style(self):
"""Update the grey style using mean+-5*std for all principal components
"""
for view_widget in MainAnalysisDialog.view_widgets:
if view_widget.pc_id is not None:
src_ds = gdal.Open(
str(get_file_path_of_layer(
view_widget.render_widget.layer)), gdal.GA_ReadOnly)
ds = src_ds.GetRasterBand(1).ReadAsArray().flatten().astype(
np.float32)
ds = ds[ds != 0]
try:
mean = np.mean(ds)
std = np.std(ds)
except:
continue
renderer = QgsSingleBandGrayRenderer(
view_widget.render_widget.layer.dataProvider(), 1)
ce = QgsContrastEnhancement(
view_widget.render_widget.layer.dataProvider().dataType(0))
ce.setContrastEnhancementAlgorithm(
QgsContrastEnhancement.StretchToMinimumMaximum)
ce.setMinimumValue(mean - 5 * std)
ce.setMaximumValue(mean + 5 * std)
renderer.setContrastEnhancement(ce)
view_widget.render_widget.layer.setRenderer(renderer)
del src_ds, ds
