Group Deconvolution
Hi @BmanClark 

Could you please provide the steps you have followed for TFLite conversion inorder to reproduce the issue?

Thanks.
 This issue is stale because it has been open for 7 days with no activity. It will be closed if no further activity occurs. Thank you. Sorry, I've been busy with my workaround... The issue still exists generally, but https://github.com/Picsart-AI-Research/MI-GAN/ has kindly added a new commit to replace the group deconvolutions in the network and avoid the issue. So to reproduce you need the previous commit of MI-GAN: 29807312b6d881b51246d83e8b6fa9b9e4f97978

With that network / github project I converted with [TinyNN](https://github.com/alibaba/TinyNeuralNetwork).

Specifically, once the TinyNN & MI-GAN projects were installed on python following their respective standard instructions, I used the following to convert the network and hit the issue.

```python
from tinynn.converter import TFLiteConverter
import torch
import sys
import argparse
import os
import numpy as np
from lib.model_zoo.migan_inference import Generator as MIGAN

model = MIGAN(resolution=512)
model.load_state_dict(torch.load('./models/migan_512_places2.pt'))
dummy_input = torch.randn(1, 4, res, res)

with torch.no_grad():
    model.cpu()
    model.eval()
    
    converter = TFLiteConverter(model, dummy_input, 'migan512.tflite')
    # converter.group_conv_rewrite = True # line to blow up network to thousands of nodes, but make conversion work by de-grouping
    converter.convert()
``` 

 Hi, this is the author of TinyNN, which is a tool to convert PyTorch models to TFLite. I've skimmed the conversation above. Actually, it is rather a feature request, not a bug. As group convolution is already supported in TFLite, it seems reasonable to get grouped transpose_convolution supported too. Internally, we have a fork of TFLite that maps the group deconvolution to a single op and then maps that to the underlying XNNPack implementation. Ideally, it could be supported here, as well. Hi @BmanClark @peterjc123 

Thanks for the information. 

I am just trying with a toy model to reproduce the issue and observed that TFLite is able to convert the transpose convolutions with groups without any error.

Please find this [gist](https://colab.research.google.com/gist/pjpratik/135971b72d0efec138e452f1b8fed66f/62181.ipynb). 

If you could provide a similar toy model, that would help us investigate the bug or feature request better.

Thanks.
 @pjpratik Yes, it doesn't fail during conversion and evaluation, but if you inspect the generated TFLite model using Netron, you can see that it is translated to a full conv_transpose node rather than a grouped one. (The number of the input channels and the output channels of the weights are equal to 32) So there is no speedup and memory savings compared with full transposed convolutions during inference, making grouped deconvolutions meaningless.

![image](https://github.com/tensorflow/tensorflow/assets/9998726/ebd6b33c-3f2d-4180-b8e9-1ddfbfb3b6e2)
 To make it clear, we need the following enhancements:
1. Update the TFLite schema to enable grouped deconvolutions so that we can have grouped weights (which is smaller)
2. Implement grouped deconvolution kernels to speedup inference Hi @peterjc123, would you be willing to make a contribution for this feature? That'll probably get it integrated the fastest. This issue is stale because it has been open for 7 days with no activity. It will be closed if no further activity occurs. Thank you. @pkgoogle Will take a look and work on this if I have time. @haozha111, can you please take a look? Thanks. This issue is stale because it has been open for 180 days with no activity. It will be closed if no further activity occurs. Thank you.
**System information**
- OS Platform and Distribution (e.g., Linux Ubuntu 16.04):  On Windows 10 / WSL2, but targeting but Android
- TensorFlow installed from (source or binary): (using PyTorch and converting to tflite from there)
- TensorFlow version (or github SHA if from source):

Using TFLite 2.8.0, but there's not been significant changes to relevant code in latest (and I'd be happy to upgrade if there were...).

**Provide the text output from tflite_convert**
I'm using TinyNN to convert to direct from PyTorch. it says:
> UserWarning: Group transposed conv is not supported if official tflite interpreter is used.
and
https://github.com/tensorflow/tensorflow/blob/master/tensorflow/lite/delegates/xnnpack/xnnpack_delegate.cc#L6213
has groups=1 hard-coded

```
Converting this network:
https://github.com/Picsart-AI-Research/MI-GAN/
Specifically, the function creating the Transpose Convolutions / Deconvolutions is at:
https://github.com/Picsart-AI-Research/MI-GAN/blob/main/lib/model_zoo/migan_inference.py#L79



