ENH: added option to set label field name

app/otbSimpleVectorization.cxx

@@ -57,6 +57,11 @@ private:
     AddParameter(ParameterType_Int, "bv", "Background Value");
     SetParameterDescription("bv", "Value corresponding to no-object.");
     SetDefaultParameterInt("bv", 0);
+    
+    AddParameter(ParameterType_String, "label", "Label field");
+    SetParameterDescription("label", "Name of the output field containing object labels (defaults to 'label')");
+    MandatoryOff("label");
+    DisableParameter("label");
 
     AddParameter(ParameterType_OutputFilename, "out", "Output GIS vector file");
     SetParameterDescription("out",
@@ -94,7 +99,11 @@ private:
 	layername             = layername.substr(0, layername.size() - (extension.size()));
 	layer                 = ogrDS->CreateLayer(layername, &oSRS, wkbPolygon, options);
 	
-	OGRFieldDefn labelField("label", OFTInteger);
+	std::string lbField = "label";
+	if (IsParameterEnabled("label"))
+		lbField = GetParameterString("label");
+	
+	OGRFieldDefn labelField(lbField.c_str(), OFTInteger);
 	layer.CreateField(labelField, true);
 
 	LabelImageToOGRDataSourceFilterType::Pointer labelToOGR = LabelImageToOGRDataSourceFilterType::New();
@@ -104,7 +113,7 @@ private:
 	  LabelImageType::Pointer        mask             = this->GetParameterUInt32Image("mask");
 	  labelToOGR->SetInputMask(mask);
 	}
-	labelToOGR->SetFieldName("label");
+	labelToOGR->SetFieldName(lbField);
 	labelToOGR->Update();
 	
 	int noObj = this->GetParameterInt("bv");
@@ -113,7 +122,7 @@ private:
 	otb::ogr::Layer::const_iterator featIt = layerTmp.begin();
 	for (; featIt != layerTmp.end(); ++featIt)
 	{
-	  if (featIt->ogr().GetFieldAsInteger("label") != noObj) {
+	  if (featIt->ogr().GetFieldAsInteger(lbField.c_str()) != noObj) {
 		otb::ogr::Feature dstFeature(layer.GetLayerDefn());
 		dstFeature.SetFrom(*featIt, TRUE);
 		layer.CreateFeature(dstFeature);