Data Compression MCQ for AKTU students.

 

(AKTU)Data Compression MCQ

1. Data compression is a ___________ in the number of bits needed to represent data.

1. Increment
2. Reduction
3. Expansion
4. None of the above

Correct option is B

2. Data compression schemes can be divided into _______ broad classes.

1. 4
2. 3
3. 2
4. 5

Correct option is C

3. Text compression is an example of ________ compression.

1. Lossless compression
2. Lossy compression
3. Both (A) and (B)
4. None of the above

Correct option is C

4.               6. A description of the model and a description of how the data differ from the model are                       encoded is called.

1. Modelling
2. Testing
3. Coding
4. Maintenance 

Correct option is B

7. The average number of bits required to represent single sample is known as:

1. Bit rate
2. Byte rate
3. Compression rate
4. All of the above

Correct option is A

8. The difference between the original and reconstruction is often called.

1. Waveform
2. Distortion
3. Noise
4. Error

Correct option is B

9. The compression of analog signal is referred to as.

1. Analog coding
2. Arithmetic coding
3. Huffman coding
4. Waveform coding

Correct option is A

10. The difference between the data and the model is called as.

1. Residual
2. Waveform
3. Distortion
4. None of the above 

Correct option is A

11. The first order entropy of the following sequence is 12323454567898910.

1. 2.25 bits/symbol
2. 3.25 bits/symbol
3. 1.25 bits/symbol
4. 5.25 bits/symbol

Correct option is B

12. The probability model also known with another name __________.

1. Knowledge model
2. Reconstruction model
3. Ignorance model
4. None of the above

Correct option is B

13. ASCII code uses the same number of bits to represent each symbol such code is called.

1. Variable length code
2. Fixedxed code
3. Fixed length code
4. None of the above

Correct option is C

14. Test the following codes are uniquely decodable or not {0,01,11}.

1. Uniquely decodable codes
2. Not uniquely decodable
3. Neither uniquely decodable nor not uniquely decodable
4. None of the following

Correct option is A

15. A code in which no codeword is a prefix to another codeword is called a.  

1. Uniquely decodable code
2. Huffman code
3. Arithmetic code
4. Prefix code

Correct option is A

16. The difference between the entropy and the average length is called.

1. Self information
2. Redundancy
3. Probability
4. None of the above

Correct option is B

17.  In Huffman tree NYT stands for ____.

1. No Yet Transmitted
2. Not Yet Transmission
3. Not Yet Transmitted
4. None of the above

Correct option is C

18.  In Golomb code the unary code of 5 is.

1. 111110
2. 000001
3. 1111100
4. 0000011

Correct option is A

19.  In Golomb code the unary code for a positive integer n is simply.

1. n 0s followed by 1
2. n 1s followed by 0
3. n 1s followed by 00
4. n 0s followed by 11

Correct option is B

20.  In Rice codes the CCSDS stands for .

1. Consultative Committee on Standard Data Science
2. Consultative Commission on Standard Data Science
3. Consultative Committee on Space  Data Standard
4. Consultative Committee on Specialized Data Science

Correct option is A

21.  In CCSDS algorithm the ________ removes correlation from the input and generates a sequence of nonnegative integers.

1. A binary coder
2. A binary generator
3. A parity checker
4. A pre-processor

Correct option is A

22.  The prefix code is also called as

1. Block code
2. Convolutional code
3. Parity code
4. Instantaneous code 

Correct option is D

23.  The binary coder generates a _______ to represent the integer sequence.

1. Byte stream
2. Bit stream
3. Character stream
4. None of the above 

Correct option is B

24.  A code in which no codeword is a prefix to another codeword is called as.

1. Prefix code
2. Parity code
3. Convolutional code
4. Block code 

Correct option is A

25.  In which codes all codeword have equal length.

1. Huffman codes
2. Golomb codes
3. Prefix codes
4. Tunstall codes

Correct option is D

27. Full form of ASCII is

1. American Standard Code for Information Intercaste
2. American Standard Codewords for Information Interchange
3. American Standard Code for Information Interchange
4. American System Code for Information Interchange

Correct option is C

28.  In n-bit Tunstall code for a source the number of codewords is.

1. Log n
2. 2n
3. 2n-1
4. 2n+1 

Correct option is B

29. The image consist of 256 rows of 256 pixels , so the uncompressed representation uses ________ bytes.

1. 65536
2. 65426
3. 66536
4. 66325

Correct option is A

30. At what rate the audio signal for each stereo channel is sampled.

1. 42.2kHz
2. 43.1kHz
3. 44.1kHz
4. 44.2kHz 

Correct option is C

31. In Rice codes the ROS is used when the last five or more blocks in a segment are all.

A.     One

B.     Zero

C.     Same

D.     None of the above

Correct option is B

32. What is the value of redundancy in Huffman codes when the probabilities are negative power of two.

1. 1
2. 2
3. 3
4. 0

     Correct option is D

33. Who was the developer of Rice codes.

A.     Robert F. Rice

B.     Robert S. Rice

C.     Robert S. Rice

D.     None of the above 

     Correct option is A

34. Which is the most popular method for generating variable length codes.

A.     Huffman coding

B.     Arithmetic coding

C.     Run length coding

D.     None of the above

Correct option is A

35. Which one of the following is not application of arithmetic coding.

A.     Bi-level image compression

B.     JBIG

C.     JBIG-2

D.     Text compression

Correct option is A

36. A static dictionary technique that is less specific to a single application is ____.

A.     Diagram coding

B.     Arithmetic coding

C.     Huffman coding

D.     All of the above 

Correct option is D

37. In LZ77 a buffer that conatins portion of the recently encoded sequence is called.

A.     Look ahead buffer

B.     Search buffer

C.     Stack buffer

D.     None of the above

Correct option is B

38      38 .  In LZ77 a buffer that contains next portion of the sequence to be encoded is called a.

1. Stack buffer
2. Look ahead buffer
3. Search buffer
4. All of the above

Correct option is B

39       39.  Which one of the following is an application of LZW compression algorithm.

1. Audio compression
2. Video compression
3. Text compression
4. Unix compress

Correct option is D

40      

41       40.  Which coding scheme use the history of the sequence to determine its encoding.

1. Huffman coding
2. Arithmetic coding
3. Prefix coding
4. None of the above

Correct option is B

42      41.  Which one of the best known context based algorithm.

1. Prediction with partial match
2. LZ77
3. LZ78
4. LZW 

Correct option is A

43     42.  CALIC stands for.

1. Context adaptive lossless image compression
2. Context adaptive lossy image compression
3. Context adaptive lossy image compression
4. None of the above

Correct option is A

44     43.  Which coding scheme that takes advantage of long runs of identical symbol.

1. Arithmetic coding
2. Move to front coding
3. Move to back coding
4. Predictive coding

Correct option is B

45     44.  In which transmission a page is scanned and converted into a sequence of black or white               pixels.

1. Audio transmission
2. Video transmission
3. Facsimile transmission
4. All of the above

Correct option is C

46    45.  Which algorithm requires that the entire sequence to be coded be available to the encoder          before the coding takes place.

1. LZW
2. LZ8
3. The borrows-wheeler transform
4. None of the above

Correct option is B

  46. Which model gives rise the run length coding.

1. Physical model
2. Probability model
3. Composite source model
4. Capon model

Correct option is C

    47. Which type of model generates representation of an image with varying spatial resolution.

1. Physical model
2. Probability model
3. Multiresolution model
4. Capon model

Correct option is B

  48. Which compression takes the advantage of relationship and correlation that extend beyond a        single symbol.

1. Image compression
2. Dynamic markav compression
3. Audio compression
4. All of the above

Correct option is D

49.Name of the two popular measure of distortion are.

1. Squared error and absolute difference
2. Fidelity and quality
3. Scalar quantization and vector quatization
4. Mean squared error and signal to noise ratio

Correct option is C

 50. Rate is define as the number of bits used to represent each sample value.

1. Maximum
2. Minimum
3. Average  
4. All of the above

Correct option is A

51. The rate distortion function R(D) specifices the _____ rate at which output of the source can be       encoded while keeping the distortion less than or equal to D.

1. Highest
2. Lowest
3. Smallest
4. Average

Correct option is 

 52. The models play an important role in the ______ of lossy compression algorithm.

1. Testing
2. Maintenance
3. Design
4. Coding

Correct option is C

53. Tunstall coding is a form of entropy coding used for

1. Lossless data compression
2. Lossy data compression
3. Both
4. None of these 

Correct option is A

 54. Which model is used to for the design and analysis of lossy compression schemes.

1. Probability model
2. Linear system model
3. Physical model
4. None of the above

Correct option is 

53. The model are based on the physics of the source output production are called.

1. Probability model
2. Physical model
3. Composite source model
4. None of the above

Correct option is 

  54. 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

1. A = 0 B = 111 C = 110 D = 10
2. A = 0 B = 11 C = 10 D = 111
3. A = 0 B = 111 C = 11 D = 101
4. A = 01 B = 111 C = 110 D = 10

Correct option is A

55. The process of representing a large possibly infinite set of values with a much smaller set is called.

A.     Uniform quantization

B.     Scalar quantization

C.     Non uniform quantization

D.     Quantization

Correct option is D

56. A mapping which divides the range of value that the source generates into number of                 intervals is called.

A.     Decoder mapping

B.     Encoder mapping

C.     Both (A) and (B)

D.     None of the above

Correct option is C

57. A mapping that generate a representation value is called.

A.     Encoder mapping

B.     Decoder mapping

C.     Multiplexer mapping

D.     Demultiplexer mapping

Correct option is A

58. 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 number of bits per letter is

1. 0 bit
2. 1 bit
3. 0 bit
4. 9 bit 

Correct option is C

59. A quantization that does not have zero an one of its representation levels is called.

A.     Midrise quantizer

B.     Midtread quantizer

C.     Scalar quantizer

D.     Vector quantizer

Correct option is A

60. Control system and audio coding schemes are the examples of quantizer.

A.     Midrise quantizer

B.     Midtread quantizer

C.     Non uniform quantizer

D.     None of the above

Correct option is C

61. In which quantization approach there is a need for side information.

A.     Forward adative

B.     Backward adaptive

C.     Uniform

D.     Scalar 

Correct option is B

62. In ____ quantization the quantizer output is available to both transmitter and receiver , there is no need for side information.

A.     Scalar

B.     Vector

C.     Forward adaptive

D.     Backward adaptive

Correct option is C

63. A quantizer also known with another name “quantization with one word memory” is called .

A.     Midrise quantizer

B.     Midtread quantizer

C.     Jayant quantizer

D.     Vector quantizer

Correct option is C

64. A nonuniform quantizer provides _______ average distortion.

1. Lowest
2. Lower
3. Average
4. Higher  

Correct option is B

65. For a given LIoyd-Max quantizer, the quantizer output and the quantization noise are

1. Diagonal
2. Square
3. Orthogonal
4. Parallel

Correct option is C

66. In companded quantization the compressor function ____ the high probability regions close to the origin.

1. Compresses
2. Expand
3. Streches
4. All of the above

Correct option is B

67.In vector quantization a set of L-diamensional vector called ____ of the vector quantizer.

1. Code vectors
2. Directory
3. Vectors
4. codebook

Correct option is C

68. LZ77 and LZ78 are the two algorithms published in papers by Abraham Lempel and Jacob Ziv in 1977 and 1978

1. Lossy data compression
2. Lossless data compression
3. Both
4. None of the above

Correct option is B

69. Each code vector is assign a ____ index.

1. Binary
2. Decimal
3. Octal
4. None of the above

Correct option is A

70. The vector in the codebook is known as.

1. Block vector
2. Quantized vector
3. Sampled vector
4. Code vector

Correct option is D

72. In vector quantization at the ____, the input vector is compared to each code vector in order to find code vector closest to the input vector.

1. Decoder
2. Encoder
3. Multiplexer
4. None of the above 

Correct option is C

73. The elements of the code vector are the _____ values of the source output.

1. Sampled
2. Binary
3. Quantized
4. None of the above

Correct option is B

74. Application of LZW

1. GIF
2. Zip
3. PNG
4. All of the above

Correct option is A

75. The LBZ stands for.

1. Linde –Buze-Gray
2. Linde –Buzo-Grey
3. Linde –Buzo-Green
4. None of the above

Correct option is B

76. In tree structured codebook the removal o subgroups is called.

1. Pruning
2. Parsing
3. Updation
4. None of the above

Correct option is A

77. The regular arrangements of output points in space are called.

1. Cell
2. Lattice
3. Pyramid
4. None of the above

Correct option is B

78. The idea with wavelets is to represent a complicated function by

A.     simple basic functions

B.     sinus functions

C.     lines

D.     square functions 

Correct option is A

79. In a typical picture, most pixels will be

A.     equal

B.     very different to their neighbors

C.     bright

D.     very similar to their neighbors 

Correct option is C

80. Without losing quality, JPEG-2000 can achieve compression ratios of

1. 2:1
2. 200:1
3. 2000:1
4. 20:1

Correct option is B

81. The best visual compression quality is achieved using

A.     Fourier transform

B.     Wavelets

C.     DCT

D.     Dolby 

Correct option is B

82. Which is the image processing technique used to improve the quality of image for human viewing?

A.     Compression

B.     Enhancement

C.     Restoration

D.     Analysis 

Correct option is B

 83. To remove archival compression and restore the data to column store compression

A.     Use ALTER TABLE

B.     Use ALTER COLUMN

C.     Use ALTER DATABASE

D.     All of the mentioned

Correct option is A

84. Point out the wrong

A.     You can enable or disable ROW or PAGE compression in online state only

B.     When you are compressing indexes, leaf-level pages can be compressed with both row and page compression

C.     Non–leaf-level pages do not receive page compression

D.     None of the mentioned 

Correct option is A

85. What is image?

A.     Picture

B.     Matrix of pixel

C.     Collection of pixel

D.     All of these

Correct option is D

86. An image transmitted using wireless network:

A.     corrupted as a result of lighting or other atmospheric

B.     non-corrupted as a result of lighting or other atmospheric

C.     corrupted as a result of pixel

D.     none of above 

Correct option is A

87. Which of the following characterizes a quantizer

1. Quantization results in a non-reversible loss of information
2. A quantizer always produces uncorrelated output samples
3. The output of a quantizer has the same entropy rate as the input
4. None of the above 

Correct option is A

88. What is the signal-to-noise ratio (SNR)?

1. The ratio of the average squared value of the source output and the squared error of the source output
2. The ratio of the average squared value of the source output and the mean squared error of the source output
3. The ratio of the average squared value of the source output and the absolute difference measure of the source output
4. None of the above 

Correct option is B

89. The output signal of a scalar quantizer has property

1. The output is a discrete signal with a finite symbol alphabet
2. The output is a discrete signal with a countable symbol alphabet (but not necessarily a finite symbol alphabet)
3. The output signal may be discrete or continuous
4. None of the above 

Correct option is B

90. What is a Lloyd quantizer?

1. For a given source, the Lloyd quantizer is the best possible scalar quantizer in ratedistortion That means, there does not exist any other scalar quantizer that yields a smaller distortion at the same rate.
2. The output of a Lloyd quantizer is a discrete signal with a uniform pmf
3. Both (A) and (B)
4. A Lloyd quantizer is the scalar quantizer that yields the minimum distortion for a given source and a given number of quantization

Correct option is D

91. Which of the following statement is correct for comparing scalar quantization and vector quantization?

1. Vector quantization improves the performance only for sources with memory. For iid sources, the best scalar quantizer has the same efficiency as the best vector quantizer
2. Vector quantization does not improve the rate-distortion performance relative to scalar quantization, but it has a lower complexity
3. By vector quantization we can always improve the rate-distortion performance relative to the best scalar quantizer
4. All of the above 

Correct option is C

92. If {x}_n is the source output and {y}_n is the reconstructed sequence, then the squared error measure is given by

1. d(x, y) = (y – x)²
2. d(x, y) = (x – y)²
3. d(x, y) = (y + x)²
4. d(x, y) = (x – y)⁴

Correct option is B

93. If {x}_n is the source output and {y}_n is the reconstructed sequence, then the absolute difference measure is given by

1. d(x, y) = |y – x|
2. d(x, y) = |x – y|
3. d(x, y) = |y + x|
4. d(x, y) = |x – y|² 

Correct option is B

94. The process of representing a           possibly infinite set of values with a much            set is called quantization

1. Large, smaller
2. Smaller, large
3. None of these

Correct option is A

95. The set of inputs and outputs of a quantizer can be

1. Only scalars
2. Only vectors
3. Scalars or vectors
4. None of these 

Correct option is C

96. Which of the folowing is/are correct for uniform quantizer

1. The simplest type of quantizer is the uniform quantizer
2. All intervals are the same size in the uniform quantizer, except possibly for the two outer intervals
3. The decision boundaries are spaced evenly
4. All of the above 

Correct option is D

97. If a Zero is assigned a decision level, then what is the type of quantizer?

1. A midtread quantizer
2. A midrise quantizer
3. A mid treat quantizer
4. None of the above 

Correct option is B

98. If a Zero is assigned a quantization level, then what is the type of quantizer?

1. A midtread quantizer
2. A midrise quantizer
3. A mid treat quantizer
4. None of the above

Correct option is A

99. The main approaches to adapting the quantizer parameters:

1. An off-line or forward adaptive approach
2. An on-line or backward adaptive approach
3. Both
4. None of the above 

Correct option is C

100. Uniform quantizer is also called as

1. Low rise quantizer
2. High rise quantizer
3. Mid rise quantizer
4. None of the above 

Correct option is C

101. Non uniform quantizer

1. Decrease
2. Increase
3. Doesn’t change
4. None of the above 

Correct option is A

102. The spectral density of white noise is .

1. Poisson
2. Exponential
3. Uniform
4. Gaussian 

Correct option is C

103. Which audio/video refers to on-demand requests for compressed audio/video files?

A.     Streaming live

B.     Streaming stored

C.     Interactive

D.     None of the above 

Correct option is B

104. According to Nyquist theorem, how many times the highest frequency we need to sample an analog signal?

A.     Three

B.     Two

C.     Four

D.     None of the above

Correct option is B

105. Which encoding is based on the science of psychoacoustics, which is the study of how people perceive sound?

1. Predictive
2. Perceptual
3. Both of the above
4. None of the above

Correct option is B

107. The minimum sampling rate is called?

A.     Data rate

B.     symbol rate

C.     Nyquist rate

D.     None of the above

Correct option is C

108. Spread spectrum is used for

A.     Encrypting signal

B.     Hiding signal

C.     Encrypting & Hiding signal

D.     None of the mentioned 

Correct option is C

109. Which is a quantization process?

A.     Rounding

B.     Truncation

C.     Rounding & Truncation

D.     None of the mentioned 

Correct option is C

110. Quantization is a……………..process.

A.     Non linear

B.     Reversible

C.     Non linear & Reversible

D.     None of the mentioned 

Correct option is C

111. The mutual information between a pair of events is

A.     Positive

B.     Negative

C.     Zero

D.     All of the mentioned 

Correct option is D

112. The SNR value can be increased by the number of levels.

1. Increasing
2. Decreasing
3. Does not depend on
4. None of the mentioned 

Correct option is A

113. 1 bit quantizer is a

A.     Hard limiter

B.     Two level comparator

C.     Hard limiter & Two level comparator

D.     None of the mentioned 

Correct option is C

114. The low pass filter at the output end of delta modulator depends on

A.     Step size

B.     Quantization noise

C.     Bandwidth

D.     None of the mentioned 

Correct option is C

115. Quantization Matrix in JPEG compression was introduced because

A.     It is computationally more efficient to work with matrix than with scalar quantization;

B.     It allows better entropy encoding due to DC and AC coefficient distribution in the 8×8 block matrix;

C.     It allows better differentiation of DC and AC coefficients in the 8×8 block matrix than a scalar quantization;

Correct option is C

116. What property has the output signal of a scalar quantizer

·        The output is a discrete signal with a countable symbol alphabet (but not necessarily a finite symbol alphabet).

·        The output is a discrete signal with a finite symbol

·        The output signal may be discrete or continuous

Correct option is A

117. Characteristic of a vector quantizer

1. Multiple quantization indexes are represented by one codeword
2. Each input symbol is represented by a fixed-length codeword
3. Multiple input symbols are represented by one quantization index
4. All of the above 

Correct option is C

118. Vector quantization is rarely used in practical applications, why?

1. The coding efficiency is the same as for scalar quantization
2. The computational complexity, in particular for the encoding, is much higher than in scalar quantization and a large codebook needs to be stored
3. It requires block Huffman coding of quantization indexes, which is very complex
4. All of the above 

Correct option is B

119. Let N represent the dimension of a vector quantizer. What statement about the performance of the best vector quantizer with dimension N is correct?

1. For N approaching infinity, the quantizer performance asymptotically approaches the rate- distortion function (theoretical limit)
2. By doubling the dimension N, the bit rate for the same distortion is halved
3. The vector quantizer performance is independent of N
4. All of the above 

Correct option is A

120. Which of the following is/are correct for the advantage of vector quantization over scalar quantization.

1. Vector Quantization can lower the average distortion with the number of reconstruction levels held constant
2. Vector Quantization can reduce the number of reconstruction levels when distortion is held constant
3. Vector Quantization is also more effective than Scalar Quantization When the source output values are not correlated
4. All of the above

Correct option is D

121. Vector quantization is used for

1. Lossy data compression
2. Lossy data correction
3. Pattern recognition
4. All of the above 

Correct option is D

122. The Linde–Buzo–Gray algorithm is a                quantization algorithm to derive a good codebook.

1. Scalar
2. Vector
3. Both
4. None of the above 

Correct option is B

123. Vector quantization is used in

1. Video coding
2. Audio coding
3. Speech coding
4. All of the above

Correct option is C

124. What are processes (Techniques) used in video coding?

1. Partition of frames into macroblocks
2. Form of Vector Quantization
3. Both (A) & (B)
4. None of these 

Correct option is C

125. The process of converting the analog sample into discrete form is called

1. Modulation
2. Multiplexing
3. Quantization
4. Sampling 

Correct option is C

126. The sequence of operations in which PCM is done is

1. Sampling, quantizing, encoding
2. Quantizing, encoding, sampling
3. Quantizing, sampling, encoding
4. None of the above

Correct option is A

127. To convert a continuous sensed data into Digital form, which of the following is required?

A.     Sampling

B.     Quantization

C.     Both Sampling and Quantization

D.     Neither Sampling nor Quantization

Correct option is C

128. For a continuous image f(x, y), Quantization is defined as

A.     Digitizing the coordinate values

B.     Digitizing the amplitude values

C.     All of the mentioned

D.     None of the mentioned

Correct option is B

129. The resulting image of sampling and quantization is considered a matrix of real numbers. By what name(s) the element of this matrix array is called

1. Image element or Picture element
2. Pixel or Pel
3. All of the mentioned
4. None of the mentioned

Correct option is C

130. Which conveys more information?

A.     High probability event

B.     Low probability event

C.     High & Low probability event

D.     None of the mentioned

Correct option is B

131. The probability density function of the envelope of narrow band noise is

A.     Uniform

B.     Gaussian

C.     Rayleigh

D.     Rician

Correct option is B

132. Which model is known as ignorance model?

A.     Physical model

B.     Markov model

C.     Probability model

D.     Composite Source Model

Correct option is C

133. Shannons theorem is also called

A.     noiseless coding theorem

B.     noisy coding theorem

C.     coding theorem

D.     noiseless theorem Answer

Correct option is A

134. Transform coding, vector quantization are examples for

A.     Pixel

B.     compression

C.     Transmission

D.     Lossy compression Answer

Correct option is D

135. Entropy Coding is an               

1. Lossless
2. Lossy
3. 0
4. None

Correct option is A

136.                is normally used for the data generated by scanning the documents, fax machine, typewriters etc.

1. Huffman Coding
2. Transformation Coding
3. Vector Quantization
4. Runlength Encoding

Correct option is D

137. Compression Technique used in Image Video is

1. Huffman Coding
2. Transformation Coding
3. Entropy Coding
4. Differential Encoding

Correct option is B

138. Compression Technique used in Audio is

1. Differential Encoding
2. Transformation Encoding
3. Entropy Coding
4. Differential & Transformation Encoding

correct option is D

139. Expansion of LZ Coding is

1. Lossy
2. Lossless
3. Lempel-ziv-welsh
4. Lempel-ziv

Correct option is D

140. Expansion of LZW Coding is

1. Lossy
2. Lossles
3. Lempel-ziv
4. Lempel-ziv-welsh

Correct option is D