Data Compression - Part 3

The redundancy is zero when

• The probabilities are positive powers of two
• The probabilities are negative powers of two
• Both
• None of the above

Which bit is reserved as a parity bit in an ASCII set?

• Sixth
• Seventh
• Eighth
• Ninth

___ Bits are needed for standard encoding if the size of the character set is X

• X+1
• log(X)
• X2
• 2X

Applications of Huffman Coding

• Text compression
• Audio compression
• Lossless image compression
• All of the above

The basic idea behind Huffman coding is to

• compress data by using fewer bits to encode fewer frequently occuring characters
• compress data by using fewer bits to encode more frequently occuring characters
• compress data by using more bits to encode more frequently occuring characters
• expand data by using fewer bits to encode more frequently occuring characters

An alphabet consist of the letters A, B, C and D. The probability of occurrence is P(A) = 0.4, P(B)= 0.1, P(C) = 0.2 and P(D) = 0.3. The Huffman code is

• A = 0 B = 111 C = 110 D = 10
• A = 0 B = 11 C = 10 D = 111
• A = 0 B = 111 C = 11 D = 101
• A = 01 B = 111 C = 110 D = 10

Huffman coding is an encoding algorithm used for

• lossless data compression
• broadband systems
• files greater than 1 Mbit
• lossy data compression

A Huffman encoder takes a set of characters with fixed length and produces a set of characters of

• random length
• fixed length
• variable length
• constant length

A Huffman code: A = 1, B = 000, C = 001, D = 01 , P(A) = 0.4, P(B) = 0.1, P(C) = 0.2, P(D) = 0.3 The average codeword length is

• 6
• 3.1
• 5.2
• 2.1

Which of the following is the first phase of JPEG?

• DCT Transformation
• Quantization
• Data Compression
• None of the above