Merge pull request #23419 from dkurt:onnx_fixes

Several fixes for ONNX importer: Expand, Gather

modules/dnn/src/onnx/onnx_importer.cpp

@@ -2435,12 +2435,18 @@ void ONNXImporter::parseExpand(LayerParams& layerParams, const opencv_onnx::Node
     }
     else
     {
-        inpShape = shape(getBlob(input0));
+        Mat blob = getBlob(input0);
+        if (constBlobsExtraInfo.find(node_proto.input(0)) != constBlobsExtraInfo.end() &&
+            getBlobExtraInfo(node_proto, 0).real_ndims == 1) {
+            inpShape = {(int)blob.total()};
+        } else {
+            inpShape = shape(blob);
+        }
     }
 
     String srcName = input0;
     // Unsqueeze and repeat along new axis
-    if (targetShape.size() == inpShape.size() + 1)
+    if (targetShape.size() > inpShape.size())
     {
         inpShape.insert(inpShape.begin(), targetShape.size() - inpShape.size(), 1);
         for (int i = 0; i < targetShape.size(); i++)
@@ -2486,7 +2492,7 @@ void ONNXImporter::parseExpand(LayerParams& layerParams, const opencv_onnx::Node
     {
         if (broadcast_axes.empty())
         {
-            addConstant(output_name, getBlob(node_proto, 0));
+            addConstant(output_name, getBlob(node_proto, 0).reshape(1, targetShape));
             return;
         }
 
@@ -2719,7 +2725,8 @@ void ONNXImporter::parseGather(LayerParams& layerParams, const opencv_onnx::Node
 
             runLayer(layerParams, inputs, output);
             output.back().convertTo(output.back(), type);
-            output.back().dims = std::max(input_real_ndims - real_ndims, 1);
+            if (real_ndims < 2)  // In case of scalars or 1D vectors, OpenCV initializes 2D cv::Mat
+                output.back().dims = std::max(input_real_ndims - real_ndims, 1);
             addConstant(node_proto.output(0), output.back());
             return;
         }

modules/dnn/test/test_onnx_importer.cpp

@@ -2487,6 +2487,11 @@ TEST_P(Test_ONNX_layers, Gelu)
     testONNXModels("gelu_approximation");
 }
 
+TEST_P(Test_ONNX_layers, OpenAI_CLIP_head)
+{
+    testONNXModels("clip-vit-base-head");
+}
+
 INSTANTIATE_TEST_CASE_P(/**/, Test_ONNX_nets, dnnBackendsAndTargets());
 
 }} // namespace