def preprocess(resized_inputs):
    """Faster R-CNN Resnet V1 preprocessing.

    VGG style channel mean subtraction as described here:
    https://gist.github.com/ksimonyan/211839e770f7b538e2d8#file-readme-md

    Args:
      resized_inputs: A [batch, height_in, width_in, channels] float32 tensor
        representing a batch of images with values between 0 and 255.0.

    Returns:
      preprocessed_inputs: A [batch, height_out, width_out, channels] float32
        tensor representing a batch of images.

    """
    channel_means = [123.68, 116.779, 103.939]
    return resized_inputs - [[channel_means]]