# SIL801 Special Topics in Multimedia System

## Assignment 3: DCT and JPEG

#### Due Date: Feb 12, 2023

- Read the paper on Discrete Cosine Transform (DCT) by Ahmed et al [1] and interesting article [2] by Ahmed on how they came up with the DCT.
- Read a report on Theory and Application of DCT by Syed Ali Khayam [3] .
- Answer the following questions briefly:
- What does Fig 2 in the paper by Ahmed et al explain?
- In what ways the properties of separability and orthogonality of DCT are useful?
- Consider the Table 1 in the report by Syed Ali Khan[3] , what does reduction of entropy indicate?

- Please read the paper on JPEG [4]
and list points which were not covered
in the class lectures on JPEG. Note that you are not required to write what is
written in the paper, but list (item wise) those parts which are different
and add to what was covered in the lectures.

**Note:**

1. This assignment is meant for reading of material related to what has been covered in
the class and apply to some of the problems as above.

2. For the answers for the above problems if there is any sharing of information from
your friend/internet/other reference material, it is desired that you please
include/acknowledge the name of that reference.

3. You may submit the report of your assignment as a pdf
document.

** References **
- [1] N. Ahmed, T. Natarajan and K. R. Rao, "Discrete Cosine Transform," IEEE Trans. Computers, 90-93, Jan. 1974.
- [2] N Ahmed, "How I Came Up with the Discrete Cosine Transform",
Digital Signal Processing, Vol 1, pp 4-5, 1991.
- [3] S A Khayam, "The Discrete Cosine Transform (DCT): Theory and Application", Technical Report, Michigan State University, 2003.
- [4] G K Wallace, "The JPEG Still Picture Compression Standard",a revised
version of the paper by the same author in Communication ACM April 1991.