Update app.py

app.py

@@ -132,7 +132,7 @@ def distortion_free_resize(image, img_size):
 
 def decode_batch_predictions(input_image):
     img_size=(128, 32)
-    input_image = tf.io.decode_png(input_image, channels=1)
+    input_image = tf.io.decode_image(input_image, channels=1,  dtype=tf.dtypes.uint8) 
     input_image = distortion_free_resize(input_image, img_size)
     input_image = tf.image.convert_image_dtype(input_image, tf.float32)/255.0