Edge Detection (ViGrA) imagery_vigra ParameterRaster|INPUT|Input|False OutputRaster|OUTPUT|Edges ParameterSelection|TYPE|Detector type|[0] Canny;[1] Shen-Castan| 0 ParameterNumber|SCALE|Operator scale| 0.000000|None| 1.000000 ParameterNumber|THRESHOLD|Gradient threshold| 0.000000|None| 1.000000