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(ELEC4140)[2005](f)midterm~dli^_69044.pdf
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Midterm (of ELEC331), 25th of October, 2005

Remarks: (1) This is an open-note exam. (2) Do all three problems.


1. (10 pts) Given a memory-less source model of 6 symbols with the probability distribution shown as follows:


Symbol
Probability

a

e

i

o

u

0.2
0.4
0.1
0.2
0.1


Find the small interval (both bounding values) for the arithmetic coding of the block of symbols . ..iouae,,,,

2. (5 pts) The 1-D -point DCT is defined as for . Now, let us assume that the input signal is changed as for all where is a constant. Find out what will happen on for each individual . N
...........102)12(cos)()()(NnNunnxuuX..
1,,1,0..Nu.
Anxnx..)()(
n
A
)(uX
u




3. (5 pts) Given an block of DCT coefficients and the quantization matrix as follows: 88.



...........................................................101120111022022412004319130101291131510163214522510282578848568119582010311850156530400
..........................9910310011298959272101120121103877864499211310481645535247710310968563722186280875129221714566957402416131455605826191412126151402416101116

Perform the quantization, generate the 1-D quantized coefficients using the zig-zag scanning order, and form the symbols based on (zero-run length, amplitude).