Fail to export net to ONNX

I'm trying to use the exportONNXNetwork function, in order to load it later into CNTK, but I'm getting a lot of warnings that I don't understand. I was hoping to get some pointers on what they might mean.

>> load('netTry.mat')
>> netFileToOMX = 'netFileToOMX_try1';
>> exportONNXNetwork(net,netFileToOMX);

This is the code i'm using, and here are the warnings:

A bunch of these:

Warning: ONNX does not support layer 'nnet.cnn.layer.Image3DInputLayer'. Exporting to ONNX operator 'com.MathWorks.Placeholder'. 
> In nnet.internal.cnn.onnx.NNTLayerConverter.makeLayerConverter (line 173)
  In nnet.internal.cnn.onnx.ConverterForNetwork/networkToGraphProto (line 80)
  In nnet.internal.cnn.onnx.ConverterForNetwork/toOnnx (line 44)
  In nnet.internal.cnn.onnx.exportONNXNetwork (line 34)
  In exportONNXNetwork (line 40) 
Warning: ONNX does not support layer 'nnet.cnn.layer.Convolution3DLayer'. Exporting to ONNX operator 'com.MathWorks.Placeholder'. 
> In nnet.internal.cnn.onnx.NNTLayerConverter.makeLayerConverter (line 173)
  In nnet.internal.cnn.onnx.ConverterForNetwork/networkToGraphProto (line 80)
  In nnet.internal.cnn.onnx.ConverterForNetwork/toOnnx (line 44)
  In nnet.internal.cnn.onnx.exportONNXNetwork (line 34)
  In exportONNXNetwork (line 40) 
Warning: ONNX does not support layer 'nnet.cnn.layer.Convolution3DLayer'. Exporting to ONNX operator 'com.MathWorks.Placeholder'. 
> In nnet.internal.cnn.onnx.NNTLayerConverter.makeLayerConverter (line 173)
  In nnet.internal.cnn.onnx.ConverterForNetwork/networkToGraphProto (line 80)
  In nnet.internal.cnn.onnx.ConverterForNetwork/toOnnx (line 44)
  In nnet.internal.cnn.onnx.exportONNXNetwork (line 34)
  In exportONNXNetwork (line 40) 

And finally this:

  Error using nnet.internal.cnn.onnx.ConverterForSoftmaxLayer/toOnnx (line 32)
Assertion failed.

Error in nnet.internal.cnn.onnx.ConverterForNetwork/networkToGraphProto (line 81)
                [nodeProto, paramInitializers, paramInputs, netInputs, netOutputs, layerMap] = toOnnx(layerConverter, TensorNameMap);

Error in nnet.internal.cnn.onnx.ConverterForNetwork/toOnnx (line 44)
            modelProto.graph            = networkToGraphProto(this);

Error in nnet.internal.cnn.onnx.exportONNXNetwork (line 34)
modelProto  = toOnnx(converter);

Error in exportONNXNetwork (line 40)
nnet.internal.cnn.onnx.exportONNXNetwork(Network, filename, varargin{:});

Any help appreciated.

Answer 1

[Don Mathis]

I don't think you'll be able to export 3d image networks until the support package supports it (expected later this year). If you're able to post your network here, I could see if there are any other potential issues besides the 3d Conv layers.

[Patrick ONeal]

Don, pardon my lack of knowledge here, but is this package being developed by Mathworks? Is there a way for me to get a good enough estimate of when exporting a 3d image network will be supported, in order to get back to my management about it? It looks very promising to us ...

[Don Mathis]

Yes, the ONNX Converter support package is being actively developed by MathWorks. However, we have a policy not to estimate when, or even if, specific future features will be available. So I can't make any promises beyond saying that exporting 3d networks is considered highly important to us.

[Patrick ONeal]

Understood! Much appreciated.

Answer 2

[Don Mathis]

Unfortunately, exporting 3D layers to ONNX is not yet supported.

[Patrick ONeal]

Thank you for your answer. What are my alternatives here?