Data Compression — Winter 2021

Explain Modeling and Coding with suitable example.

Define the following terms: (1) Compression Ratio (2) Rate (3) Distortion Measure

What is data compression. Distinguish Lossy and Lossless compression.

Find the average length of the code in (b) and its redundancy.

Describe uniquely decodable code with example. Determine whether the following codes are uniquely decodable or not. 1. {0,01,11,111} 2. {0,01,110,111} 3. {0,10,110,111} 4. {1,10,110,111}

List out applications of data compression.

Consider an alphabet A={a1,a2,a3,a4,a5} with probabilities P(a1)=0.15, P(a2)=0.04, P(a3)=0.26, P(a4)=0.05 and P(a5)=0.50.

Differentiate traditional Huffman and minimum variance Huffman algorithms.

Calculate the entropy of this source.

Find a Huffman code for this source.

Compare Arithmetic and Huffman Coding.

What is LZW compression? Explain with the help of an example.

Consider an alphabet A={a1,a2,a3} with the probabilities P(a1)=0.2, P(a2)=0.3, P(a3)=0.5. Find the real valued tag for the sequence “a1 a1 a3 a2 a3 a1”

Define a term: Context Based Compression.

What is adaptive Huffman encoding? Explain its update and encoding procedure with example.

What is Golomb Code? Find Golomb code for n=0,1,…,15 and m=5.

Describe ppm (prediction with partial match) with example.1

Differentiate static and adaptive dictionary coding scheme.

Explain Burrows-Wheeler Transform with example.

Encode a string “cabracadabrarrarrad” using LZ77 algorithm. Also show its decoding.

Explain Quantization problem with example.

Differentiate Uniform Quantization and Non-Uniform Quantization.

Write a note on JPEG-LS.

Discuss advantages of Vector Quantization over Scalar Quantization.

Explain Vector Quantization? Write down the procedure of Vector Quantization.

What is Adaptive Quantization? Explain various approaches of Adaptive Quantization.

Discuss Laplacian Distribution.

Explain CALIC in detail.