title: Is it impossible to quantization the .tflite file? (OSError Occurred)
body: <p>I have to try the quantization to my model(tflite).</p>
  <p>I want to change float32 to float 16 through the dynamic range quantization.</p>
  <p>This is my code:</p>
  <pre><code>import tensorflow as tf
  import json
  import sys
  import pprint
  from tensorflow import keras
  import numpy as np
  
  converter = tf.lite.TFLiteConverter.from_saved_model('models')
  converter.optimizations = [tf.lite.Optimize.DEFAULT]
  converter.target_spec.supported_types = [tf.float16]
  tflite_quant_model = converter.convert()
  open(&quot;quant.tflite&quot;, &quot;wb&quot;).write(tflite_quant_model)
  </code></pre>
  <p>In my MacBook, there is a folder called 'models', which contains two tflite files there.</p>
  <p>When I execute the code, the following error occurs:</p>
  <pre><code>converter = tf.lite.TFLiteConverter.from_saved_model('quantization')
  OSError: SavedModel file does not exist at: models/{saved_model.pbtxt|saved_model.pb}
  </code></pre>
  <p>I checked most of the posts in stack overflow, but I couldn't find a solution.</p>
  <p>Please review my code and give me some advice.</p>
  <p>I uploaded my tflite file because I guess it would be necessary to check if there was a problem.</p>
  <p>This is my model(download link):</p>
  <pre><code>https://drive.google.com/file/d/13gft7bREsv2vZYFvfoCiP5ndxHkfGKIM/view?usp=sharing
  </code></pre>
  <p>Thank you so much.</p>