I am studying this paper.
In one of the figures in the paper (Fig 5.b and Fig 5.c) DWT architecture is given using db2 and filter bank.
I don't understand how Lo_D and Hi_D have size half of input image size? If we see the figures there is no downsampler. Then how the size of the Lo_D and Hi_D have half the size of image (either row wise or column wise)?
Please explain me how single level DWT is implemented using filter banks? How the size of the decomposition values is half of the input (i.e. image) when filter banks are used to implement DWT?