meanstddev.py 文件源码

def _covariance_ops(image, covariance, total, mean, num_threads):
    num = tf.mul(tf.shape(image)[0], tf.shape(image)[1])
    num = tf.cast(num, tf.float32)

    mean_tiled = util.replicate_to_image_shape(image, mean)

    remainders = tf.sub(image, mean_tiled)
    remainders_stack = tf.pack([remainders, remainders, remainders])
    remainders_stack_transposed = tf.transpose(remainders_stack, [3, 1, 2, 0])
    pseudo_squares = tf.mul(remainders_stack, remainders_stack_transposed)
    sum_of_squares = tf.reduce_sum(pseudo_squares, [1, 2])

    queue = _make_queue([sum_of_squares, num], [[3, 3], []], num_threads, 'covariance_queue')

    img_sum_sq, img_num = queue.dequeue()
    covariance_update = covariance.assign_add(img_sum_sq)
    total_update = total.assign_add(img_num)

    return [covariance_update, total_update]