I trained a custom YOLOv7 object detection model in Google Colab. I exported it to .onnx file using this command:
python export.py --weights runs/train/exp/weights/best.pt --grid --end2end --simplify --topk-all 100 --iou-thres 0.65 --conf-thres 0.3 --img-size 640 640 --max-wh 640
This is my code to load the model:
import cv2
net = cv2.dnn.readNet('runs/train/exp/weights/best.onnx')
When I run the code above, I get this error:
error: OpenCV(4.6.0) /io/opencv/modules/dnn/src/onnx/onnx_importer.cpp:1040: error: (-2:Unspecified error) in function 'handleNode'
> Node [NonMaxSuppression@ai.onnx]:(onnx_node!NonMaxSuppression_370) parse error: OpenCV(4.6.0) /io/opencv/modules/dnn/src/layer_internals.hpp:110: error: (-2:Unspecified error) Can't create layer "onnx_node!NonMaxSuppression_370" of type "NonMaxSuppression" in function 'getLayerInstance'
However, this python code loads the model successfully:
import onnx
onnx_model = onnx.load('runs/train/exp/weights/best.onnx')
onnx.checker.check_model(onnx_model)
So seems like the issue is in OpenCV?
The .onnx file is in the correct directory.
Enviroment:
opencv-python: 4.6.0.66
torch: 1.11.0
onnx: 1.11.0
CUDA: 11.2
My PyTorch was previously version 1.12.0, but I got similar issues too. Then I read somewhere that downgrading to 1.11.0 should fix my problem. It didn't.
I downloaded a pre-exported .onnx file from google and it loaded successfully using the same code. Why can't I do it now?
