No mobile'phones,J MAKE UP MDLCEO1

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Course & Branch : M. Tech.- Digital Electronics and Communication Semester : I

Subject . Digital Signal Compression Max. Marks : 100Subject Code : MDLCEO1 Duration : 3Hrs

Instruction to the Candidates: Answer any five full questions selecting one from each unit.

1 a)UNIT - I

Explain the necessary conditions for an optimal variable length binary codes.b) Determine whether the following codes are uniquely decodable or not.

1)0,01,11,111ii) 0, 01, 110, 111iii) 0, 10, 110, 111iv) 1, 10, 110, 111

c) Design an adaptive Huffman code for the sequence AAFCCCBD and show that it is (08)lossless.

1 M

M S RAMAIAH INSTITUTE OF TECHNOLOGY(AUTONOMOUS INSTITUTE, AFFILIATED TO VTU)

BANGALORE - 560 054MAKE UP EXAMINATIONS - FEBRUARY 2012

2. a) Explain CCSDS recommendation for lossless compression.b) Consider a source A ={aa2,a3} with probabilities 0.7, 0.2, 0.1 respectively. Calculate

entropy. Construct Huffman code tree and calculate average length. Construct Tunstall code andcalculate rate.

c) Explain a two state Markov Model for a binary source.

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(04)UNIT - II

3. a) For the given sequence SWISSBMISS, using arithmetic code generate the tag value and (08)decipher the tag.

b) Apply BWT for the sequence "abraca". Code and decode the sequence and mention (08)whether it is lossy or not.

c) Explain briefly compression in the graphics interchange format. (04)

4. a) The output of LZW encoder is the following sequence (10)5,2,3,3,2,1,6,8,10,12,9,11,7,16,5,4,11,21,23,4. Consider the initial sequence{B, a, b, o, w). Decode the sequence and calculate compression ratio. Encode thedecoded sequence using the same initial directory. Does your answer match the sequencegiven above?

b) Explain following: (i) Run length coding (ii) JPEG-LS (10)Page 1 of 2

MAKE UP MDLCEOIUNIT - III

5. a) Explain conditional entropy and average mutual information. (08)b) Explain LBG algorithm for designing a codebook in vector quantization. Explain any (08)

three initialization techniques for the LBG algorithm.c) Mention main features of CFDM. (04)

6. a) Determine the Lloyd-Max decision and reconstruction levels for M=4 and the uniform (10)probability function in the range of [-A, A] . Comment on the result.

b) Explain adaptive predictionin DPCM. (05)c) Explain tree structured vector quantization. (05)

UNIT - IV7. a) Mention algorithmic steps involved to obtain KL transform. (04)

b) Define mathematically DCT and inverse DCT. For the given input calculate DCT (08)coefficients. 85, -65, 15, 30, -56, 35, 90, 60

c) Encode the following 2-level wavelet decomposed array using SPRIT algorithm. (08)34 0 1 -10 0 -1 14 -4-4 4

10 -66 -10

8. a) With the block diagram explain compression schemes in JPEG. Compare JPEG and (10)JPEG-2000. r-

b) Explain Hadamard transform. Apply Hadamard transform to the sample image) 3 3

Write the sample image in terms of Hadamard basis matrices and coefficients. L

9. a)UNIT - V

Explain motion compensation technique for video compression with examples.b) Suppose after the transform the set of first eight coefficients are given by 29.5, 6.1, 1.93,

0.

c)

a)

-2.01, 1.23, -0.95, 2.11. Assume reconstruction value as IV X Q' , Yu = 4.reconstruction error.Write short notes on model based coding.

With the neat block diagram, explain MPEG-4 video coding.

Calculate

b)c)

Describe compression issues in ATM networks.Explain Loop Filter in video coding.

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