Convolution2DTransposeBias support

[vsi-minggang]

I am filing this jira separately and closing the originating jira.
Mediapipe framework is very popular and has lots of useful models. A lot of these models use the Convolution2DTransposeBias custom operation. Please evaluate if it would be possible to add support for this operation. It is effectively a transposed convolution layer + add bias implemented in one operation. You can find more details in this post:
google-ai-edge/mediapipe#245

The operation is supported by tflite for a while in the GPU delegate and the XNNPACK delegate. You may even have this operation supported already but just need a code to recognize it and to convert it into acuity operation.

The GPU implementation in tflite is here:
https://github.com/tensorflow/tensorflow/blob/master/tensorflow/lite/delegates/gpu/gl/kernels/transpose_conv.cc

The XNNPACK implementation is here:
https://github.com/google/XNNPACK/blob/master/src/subgraph/deconvolution-2d.c#L356

It is effectively a transposed convolution layer + add bias implemented in one operation. You can find more details in this post:
google-ai-edge/mediapipe#245

the XNNPACK delegate implements the operation but it does not register it for some reason. You need to add a following code to your application:

/registration function/
TfLiteRegistration* RegisterConvolution2DTransposeBias() {
static TfLiteRegistration reg = {nullptr, nullptr, nullptr, nullptr};
return ®
}
... /somewhere down below where resolver is created/

// Build the interpreter with the InterpreterBuilder.
// Note: all Interpreters should be built with the InterpreterBuilder,
// which allocates memory for the Intrepter and does various set up
// tasks so that the Interpreter can read the provided model.
tflite::ops::builtin::BuiltinOpResolver resolver;
/must add custom op for it to be resolved/
resolver.AddCustom("Convolution2DTransposeBias", RegisterConvolution2DTransposeBias());

tflite::InterpreterBuilder builder(*model, resolver);