Merge pull request opencv#18181 from l-bat:onnx_pow

Author: alalek

modules/dnn/src/onnx/onnx_importer.cpp

@@ -712,6 +712,19 @@ void ONNXImporter::populateNet(Net dstNet)
                 layerParams.set("bias_term", true);
             }
         }
+        else if (layer_type == "Pow")
+        {
+            if (layer_id.find(node_proto.input(1)) != layer_id.end())
+                CV_Error(Error::StsNotImplemented, "Unsupported Pow op with variable power");
+
+            Mat blob = getBlob(node_proto, constBlobs, 1);
+            if (blob.total() != 1)
+                CV_Error(Error::StsNotImplemented, "Pow op supports only scalar power");
+
+            blob.convertTo(blob, CV_32F);
+            layerParams.type = "Power";
+            layerParams.set("power", blob.at<float>(0));
+        }
         else if (layer_type == "Max")
         {
             layerParams.type = "Eltwise";

modules/dnn/test/test_onnx_importer.cpp

@@ -283,6 +283,11 @@ TEST_P(Test_ONNX_layers, Cast)
     testONNXModels("cast");
 }
 
+TEST_P(Test_ONNX_layers, Power)
+{
+    testONNXModels("pow2", npy, 0, 0, false, false);
+}
+
 TEST_P(Test_ONNX_layers, Concatenation)
 {
     if (backend == DNN_BACKEND_INFERENCE_ENGINE_NN_BUILDER_2019)