Missing op InvertPermutation

[satyajithj]

Hi. I would like to add the InvertPermutation op to this project.
How do I get started?

[lucienwang1009]

@fuzzyBatman It seems too complex to compose this op into onnx subgraph. We may need onnx's support to convert this op.

[satyajithj]

Oh. Do you have an idea about the process?
Should this op be added to onnx, or to tf-onnx with some feature support from onnx?

[lucienwang1009]

I believe it should be added to onnx. @guschmue for comments.

[guschmue]

If we need a new op to onnx the process is sometime like this:
-submit a pr to onnx and get it accepted
-wait for the implementation in onnxruntime (we need that only so we can add unit tests in tf2onnx)
-add support for the new op to tf2onnx

[satyajithj]

@lucienwang1009 @guschmue I do not understand how ONNX works. I read the adding a new operator section but I am little confused.

Say I want to add the invert_permutation op to ONNX. I should submit a PR to ONNX which contains the Op schema, definition in docs and some test cases, as done in the EyeLike op example PR, and that is it? The implementation is done elsewhere?

[zhijxu-MS]

ONNX defines opetation schema.
ONNX backend, for example ONNXRunTime, implements ONNX opetaion.

[satyajithj]

@zhijxu-MS Thanks!