How to get center crop about dali HOT 6 CLOSED

@pipeline_def(batch_size=1, num_threads=8,device_id=1)
def TritonLoadingPipeline():
    
    img_files = fn.external_source(name="DALI_INPUT_0")
    shapes = fn.peek_image_shape(img_files)
    size = fn.cast(fn.reductions.min(shapes[0:2]), dtype=types.FLOAT)
    images = fn.decoders.image_crop(img_files, crop=fn.stack(size, size))
    resized = fn.resize(images, size=(224, 224), mode="not_smaller")
    
    normalized_images = fn.normalize(
        resized, 
        mean=MEAN / SCALE,
        stddev=STD ,
        scale=SCALE,
        dtype=types.FLOAT,
        device="cpu",
    )
#     outputs_fp16 = fn.cast(normalized_images, dtype=types.FLOAT)
    
        
    return normalized_images 

TypeError                                 Traceback (most recent call last)
Input In [160], in <cell line: 1>()
----> 1 pipe = TritonLoadingPipeline()
      2 pipe.build()

File /opt/conda/lib/python3.8/site-packages/nvidia/dali/pipeline.py:1317, in pipeline_def.<locals>.actual_decorator.<locals>.create_pipeline(*args, **kwargs)
   1315 pipe = Pipeline(**{**pipeline_kwargs, **ctor_args})  # Merge and overwrite dict
   1316 with pipe:
-> 1317     pipe_outputs = func(*args, **fn_kwargs)
   1318     if isinstance(pipe_outputs, tuple):
   1319         po = pipe_outputs

Input In [159], in TritonLoadingPipeline()
      5 shapes = fn.peek_image_shape(img_files)
      6 size = fn.cast(fn.reductions.min(shapes[0:2]), dtype=types.FLOAT)
----> 7 images = fn.decoders.image_crop(img_files, crop=fn.stack(size, size))
      8 resized = fn.resize(images, size=(224, 224), mode="not_smaller")
     10 normalized_images = fn.normalize(
     11     resized, 
     12     mean=MEAN / SCALE,
   (...)
     16     device="cpu",
     17 )

File /opt/conda/lib/python3.8/site-packages/nvidia/dali/fn.py:84, in _wrap_op_fn.<locals>.fn_wrapper(*inputs, **kwargs)
     82     return current_pipeline._wrap_op_call(op_wrapper, inputs, kwargs)
     83 else:
---> 84     return op_wrapper(*inputs, **kwargs)

File /opt/conda/lib/python3.8/site-packages/nvidia/dali/fn.py:76, in _wrap_op_fn.<locals>.op_wrapper(*inputs, **kwargs)
     73 if "device" not in init_args:
     74     init_args["device"] = default_dev
---> 76 return op_class(**init_args)(*inputs, **call_args)

File /opt/conda/lib/python3.8/site-packages/nvidia/dali/ops.py:627, in python_op_factory.<locals>.Operator.__call__(self, *inputs, **kwargs)
    625 op_instances = []
    626 for input_set in input_sets:
--> 627     op_instances.append(_OperatorInstance(input_set, self, **kwargs))
    628     op_instances[-1].generate_outputs()
    630 # Tie the instances together

File /opt/conda/lib/python3.8/site-packages/nvidia/dali/ops.py:433, in _OperatorInstance.__init__(self, inputs, op, **kwargs)
    426     except Exception as e:
    427         raise TypeError(
    428                 ("Expected inputs of type " +
    429                 "`DataNode` or convertible to constant nodes. Received " +
    430                 "input `{}` of type '{}'.")
    431                 .format(k, type(arg_inp).__name__)) from e
--> 433 _check_arg_input(op._schema, type(self._op).__name__, k)
    435 self._spec.AddArgumentInput(k, arg_inp.name)
    436 self._inputs = list(self._inputs) + [arg_inp]

File /opt/conda/lib/python3.8/site-packages/nvidia/dali/ops.py:528, in _check_arg_input(schema, op_name, name)
    526     return
    527 if not schema.IsTensorArgument(name):
--> 528     raise TypeError("The argument `{}` for operator `{}` should not be a `DataNode` but a {}".format(
    529         name, op_name, _type_name_convert_to_string(schema.GetArgumentType(name), False)))

TypeError: The argument `crop` for operator `ImageCrop` should not be a `DataNode` but a float or list of float