OpenCV cannot import simplified version of ONNX PyTorch FasterRCNN #23663
Description
System Information
opencv-python-rolling-4.7.0.20230520
Windows 10
Python 3.10.4
Detailed description
While facing the issue described here: #21634, I tried the simplified version (apply onnxsim as a usual workaround) and get the following error:
modelOpenCV = cv2.dnn.readNetFromONNX(r"D:\Local\devel\Python\PyTorch\faster-rcnn-object-detection-with-pytorch\output\FasterRCNN_ResNet50_FPN_V2_Sim.onnx")
cv2.error: OpenCV(4.7.0-dev) D:\a\opencv-python\opencv-python\opencv\modules\dnn\src\onnx\onnx_importer.cpp:1081: error: (-2:Unspecified error) in function 'cv::dnn::dnn4_v20221220::ONNXImporter::handleNode'
> Node [Split@ai.onnx]:(onnx_node!/Split) parse error: OpenCV(4.7.0-dev) D:\a\opencv-python\opencv-python\opencv\modules\dnn\src\onnx\onnx_importer.cpp:1364: error: (-215:Assertion failed) numSplits > 1 in function 'cv::dnn::dnn4_v20221220::ONNXImporter::parseSplit'
Steps to reproduce
modelOpenCV = cv2.dnn.readNetFromONNX
Model is provided here: https://drive.google.com/file/d/1utWoIRxMZhPeKg6Wx3OpLSKpuAjPNjHV/view?usp=sharing
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 any solution
- I updated to the latest OpenCV version and the issue is still there
- There is reproducer code and related data files (videos, images, onnx, etc)