def loadLabelImage(imagepath, labeldescriptor = None): """ Load a labeled single band raster in the canvas Keyword arguments: imagepath -- the path to the image labeldescriptor -- a dictionnary for label (int) to tuple (QColor, QString) conversion """ if imagepath is None: return name = os.path.splitext( os.path.basename(imagepath) )[0] qgslayer = QgsRasterLayer(imagepath, name) if not qgslayer.isValid(): QtGui.QMessageBox.critical(None, u"Erreur", u"Impossible de charger la couche %s" % unicode(imagepath)) QgsMapLayerRegistry.instance().addMapLayer(qgslayer) qgslayer.setDrawingStyle('SingleBandPseudoColor') colorlist = [] max_label = 0 for label in sorted(labeldescriptor.keys()): color = labeldescriptor[label][0] labeltxt = labeldescriptor[label][1] colorlist.append(QgsColorRampShader.ColorRampItem(label, color, labeltxt)) if labeltxt > max_label: max_label = labeltxt s = QgsRasterShader() c = QgsColorRampShader() c.setColorRampType(QgsColorRampShader.INTERPOLATED) c.setColorRampItemList(colorlist) s.setRasterShaderFunction(c) ps = QgsSingleBandPseudoColorRenderer(qgslayer.dataProvider(), 1, s) qgslayer.setRenderer(ps) for bandNo in range(1,qgslayer.dataProvider().bandCount()+1): qgslayer.dataProvider().setUseSrcNoDataValue( bandNo, False ) QGisLayers.iface.legendInterface().refreshLayerSymbology(qgslayer) if hasattr(qgslayer, "setCacheImage"): qgslayer.setCacheImage(None) qgslayer.triggerRepaint()