"""
Template for user preprocessing.
"""
def preprocess(config, prev_output):
    """Template preprocess function.

    Arguments:
        config: TestConfig class that holds the user's input config and options
        prev_output: Output passed in from a previous stage needed for this preprocess
    """
    # preprocessing work goes here

    # fill in any data you want to pass to the postprocess function to use
    # pre_data = {}

    # arrays should be in channel last format: (1, h, w, c)
    # return [array1, array2], pre_data
    pass