What is the use of “phaseShift” function？？

[toddwyl]

I am reimplement the paper SRGAN in paddlepaddle, I should implement the pixelshuffle function.
I dont understand the use of the phaseShift which u implement in

SRGAN-tensorflow/lib/ops.py

Line 107 in de8d958

def phaseShift(inputs, scale, shape_1, shape_2):

Can u help me?

[T5eng]

it is a upsample method from "Real-Time Single Image and Video Super-Resolution Using an Efficient Sub-Pixel Convolutional Neural Network"