Expected input[1, 3, 224, 224] to have 4 channels, but got 3 channels instead

1

Trying to convert a pytorch model to onnx, i have create a dummy_input of shape (1, 3, 224, 224) and while running the below code i get following error

RuntimeError: Given groups=1, weight of size 32 4 3 3, expected input[1, 3, 224, 224] to have 4 channels, but got 3 channels instead

dummy_input.shape = (1, 3, 224, 224)

Here is the code :

    input_shape = (3, 224, 224)
    model_onnx_path = "torch_model.onnx"
    model.train(False)

    # Export the model to an ONNX file
    dummy_input = Variable(torch.randn(1, *input_shape))
    print('dummy_input shape : ', str(dummy_input.shape))
    output = torch.onnx.export(model,
                              dummy_input,
                              model_onnx_path,
                              verbose=False)
    print("Export of torch_model.onnx complete!")

Is there anything wrong in this code, please correct me.

2

A conv layer (probably the first one) expects 4 input channels, while your data only contains 3 channels.
Change the data shape to [batch_size, 4, 224, 224] or the in_channels to 3 in the corresponding conv layer.

3

Thanks it worked with 4 channel.