TFLite CNN model quantization error
+1 
I was having the same issue last week with CONV_2D op after quantization, any hints on the issue are appreciated.  @sushreebarsa 
Thank you, Hello, @Marouan-st! The provided drive link is not accessible to me. Could you please provide the access or share the colab gist to replicate the issue reported here. 
Thank you!  > Hello, @Marouan-st! The provided drive link is not accessible to me. Could you please provide the access or share the colab gist to replicate the issue reported here. Thank you!

Oh I'm sorry... Access should be provided now. Hi, I have the same issue and can produce it with only a few lines of code.

```
import tensorflow as tf

input_data = tf.random.normal([1, 1088, 1])
filters = tf.random.uniform([65, 1, 1])

@tf.function
def my_conv1d(input, filters):
  print("Tracing!")
  output = tf.nn.conv1d(input, filters, 1, 'VALID')
  return output

def representative_dataset():
  for _ in range(5000):
    yield [tf.random.normal([1, 1088, 1]), tf.random.uniform([65, 1, 1])]

concrete_func = my_conv1d.get_concrete_function(input_data, filters)

converter = tf.lite.TFLiteConverter.from_concrete_functions([concrete_func],
                                                            my_conv1d)

converter.optimizations = [tf.lite.Optimize.DEFAULT]
converter.representative_dataset = representative_dataset
converter.target_spec.supported_ops = [tf.lite.OpsSet.TFLITE_BUILTINS_INT8]

tflite_model = converter.convert()

interpreter = tf.lite.Interpreter(model_content=tflite_model)
interpreter.allocate_tensors()
```
The call `interpreter.allocate_tensors()` produces:
`RuntimeError: tensorflow/lite/kernels/conv.cc:374 affine_quantization->zero_point->data[i] != 0 (-128 != 0)Node number 4 (CONV_2D) failed to prepare.Failed to apply the default TensorFlow Lite delegate indexed at 0.`

When I don't use
```
converter.representative_dataset = representative_dataset
converter.target_spec.supported_ops = [tf.lite.OpsSet.TFLITE_BUILTINS_INT8]
```
no error occours. Any ideas what to do? I was able to reproduce the issue. Please find this [gist](https://colab.research.google.com/gist/pjpratik/e601014213966dfdfdfdd31c5b805594/62171.ipynb).

The zero point calibration for the filters seems to be an issue here.

@pkgoogle Could you please look into this issue?

Thanks. I was able to reproduce w/ the same gist above.

@arfaian can you please take a look? Thanks.
### 1. System information

- OS Platform and Distribution : Ubuntu 22.04.3 LTS
- TensorFlow installation: pip install tensorflow (virtual env: venv)
- TensorFlow library: pip package -> tensorflow 2.14.0

### 2. Code

Colab to build the models and reproduce the issue:

[Reproduce the issue](https://colab.research.google.com/drive/1sx7qmXfP5RA1ituF5Fmh8X-cy0-M7Xol?usp=sharing)


### 3. Failure after conversion
Hi, I'm having an issue when trying to use signatures of quantized tflite CNN model.

The conversion and quantization go well, but when I try to use infer or fine_tune signatures, I get the following error which seems to be related to the quantization process:

RuntimeError: tensorflow/lite/kernels/conv.cc:374 affine_quantization->zero_point->data[i] != 0 (-24 != 0)Node number 21 (CONV_2D) failed to prepare.tensorflow/lite/kernels/conv.cc:374 affine_quantization->zero_point->data[i] != 0 (-24 != 0)Node number 41 (CONV_2D) failed to prepare.


**Note**: I don't get this error with the exact same code using linear model instead of CNN.

Thanks for your help