ERROR on cv::dnn::readNetFromONNX(..) during processing node [Gather] with 2 inputs and 1 outputs

[rayray41414141]

System information (version)

• OpenCV => 4.5.4
• Operating System / Platform => Windows 64 Bit
• Compiler => VisualStudio 2019

Detailed description

I have created a model in tensorflow and converted it to onnx with tf2onnx.
It seems like the interpreter cannot parse the gather node.
The following error is thown on cv::dnn::readNetFromONNX(..):

[ INFO:0] global C:\build\master_winpack-build-win64-vc15\opencv\modules\dnn\src\onnx\onnx_importer.cpp (602) cv::dnn::dnn4_v20211004::ONNXImporter::populateNet DNN/ONNX: loading ONNX v7 model produced by 'tf2onnx':1.10.0. Number of nodes = 212, inputs = 1, outputs = 1
OpenCV(4.5.4) Error: Assertion failed (indexMat.total() == 1) in cv::dnn::dnn4_v20211004::ONNXImporter::parseGather, file C:\build\master_winpack-build-win64-vc15\opencv\modules\dnn\src\onnx\onnx_importer.cpp, line 2200
[ERROR:0] global C:\build\master_winpack-build-win64-vc15\opencv\modules\dnn\src\onnx\onnx_importer.cpp (720) cv::dnn::dnn4_v20211004::ONNXImporter::handleNode DNN/ONNX: ERROR during processing node with 2 inputs and 1 outputs: [Gather]:(Shape__224:0)
[ INFO:0] global C:\build\master_winpack-build-win64-vc15\opencv\modules\dnn\src\onnx\onnx_importer.cpp (724) cv::dnn::dnn4_v20211004::ONNXImporter::handleNode     Input[0] = 'Shape__820:0'
[ INFO:0] global C:\build\master_winpack-build-win64-vc15\opencv\modules\dnn\src\onnx\onnx_importer.cpp (724) cv::dnn::dnn4_v20211004::ONNXImporter::handleNode     Input[1] = 'Const__872'
[ INFO:0] global C:\build\master_winpack-build-win64-vc15\opencv\modules\dnn\src\onnx\onnx_importer.cpp (728) cv::dnn::dnn4_v20211004::ONNXImporter::handleNode     Output[0] = 'Shape__224:0'
OpenCV(4.5.4) Error: Unspecified error (> Node [Gather]:(Shape__224:0) parse error: OpenCV(4.5.4) C:\build\master_winpack-build-win64-vc15\opencv\modules\dnn\src\onnx\onnx_importer.cpp:2200: error: (-215:Assertion failed) indexMat.total() == 1 in function 'cv::dnn::dnn4_v20211004::ONNXImporter::parseGather'
> ) in cv::dnn::dnn4_v20211004::ONNXImporter::handleNode, file C:\build\master_winpack-build-win64-vc15\opencv\modules\dnn\src\onnx\onnx_importer.cpp, line 739

Convertion was performed using this command:
python -m tf2onnx.convert --keras .\saved_model\ --output .\models\tf2onnx_keras.onnx --opset 14

Here the node from the error log. netron.app.

Steps to reproduce

Onnx model:
tf2onnx_keras.zip

The Code:

auto onnx_model = cv::dnn::readNetFromONNX("tf2onnx_keras.onnx");

Issue submission checklist

• I report the issue, it's not a question
• I checked the problem with documentation, FAQ, open issues,
  forum.opencv.org, Stack Overflow, etc and have not found solution
• I updated to latest OpenCV version and the issue is still there
• There is reproducer code and related data files: videos, images, onnx, etc

[rayray41414141]

I do have dynamic input shape.
Maybe I've got the same problem like #19347?

[alalek]

Problem is similar to #19347

There is Shape node (Shape__820:0) with dynamic input (non-constant during model importing). These cases are not supported yet in OpenCV.

Lets track progress in one issue: #19347