effects.py 文件源码

def density_map(tensor, shape):
    """
    """

    height, width, channels = shape

    bins = max(height, width)

    # values = value_map(tensor, shape, keep_dims=True)
    # values = tf.minimum(tf.maximum(tensor, 0.0), 1.0)  # TODO: Get this to work with HDR data
    values = tensor

    # https://stackoverflow.com/a/34143927
    binned_values = tf.cast(tf.reshape(values * (bins - 1), [-1]), tf.int32)
    ones = tf.ones_like(binned_values, dtype=tf.int32)
    counts = tf.unsorted_segment_sum(ones, binned_values, bins)

    out = tf.gather(counts, tf.cast(values[:, :] * (bins - 1), tf.int32))

    return tf.ones(shape) * normalize(tf.cast(out, tf.float32))