Quiznetik

Data Compression and Data Retrieval | Set 1

1. Makes the file smaller by deleting parts of the file permanently (forever)

Correct : A. Lossy Compression

2. Which of these is an advantage for Lossy compression?

Correct : A. The file size becomes significantly (much) smaller

3. Which of the following would not be suitable for Lossy Compression?

Correct : D. Text

4. Lossy or lossless? This type of compression does not get rid of any data

Correct : B. Lossless

5. Lossy or lossless? Used for web images as it gives the smallest file size - this makes images easier to upload/download/share.

Correct : A. Lossy

6. What type of compression allows you to reconstruct the original data?

Correct : A. Lossless compression

7. What are the key reasons for compressing data?

Correct : D. A and b

8. Lossless compression...

Correct : D. a and c

9. Lossy compression...

Correct : D. all of the above

10. Dictionary based compression...

Correct : D. all of the above

11. Run-length encoding..

Correct : D. all of the above

12. Hashing gives each item

Correct : D. A unique address

13. When is Run Length Encoding used?

Correct : A. When we want to compress patterns of data

14. What is the correct Run-length encoding for the data: cccmmmmmsssssdcccccc

Correct : A. 3c5m5s1d6c

15. Which of the following are not in a compressed format?

Correct : B. Bitmap

16. Identify types of lossless compression

Correct : D. a and b

17. Digitizing the image intensity amplitude is called

Correct : B. Quantization

18. Compressed image can be recovered back by

Correct : B. Image Decompression

19. Digital video is sequence of

Correct : C. Frames

20. Coding redundancy works on

Correct : C. Intensity

21. 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

Correct : B. A = 0 , B = 111 , C = 110 , D = 10

22. The basic idea behind huffman coding is to

Correct : B. Compress data by using fewer bits to encode more frequently occurring characters

23. Huffman coding is an encoding algorithm used for

Correct : C. Lossless Data Compression

24. A huffman encoder takes a set of characters with fixed length and produces a set of characters of

Correct : D. Variable Length

25. 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

Correct : D. 1.9 Bit

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

Correct : B. Simple Basic Functions

27. Down sampling is to make a digital image file smaller by

Correct : C. Removing pixels

28. In a typical picture, most pixels will be

Correct : A. Very similar to their neighbors

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

Correct : C. 200:1

30. The best visual compression quality is achieved using

Correct : B. Wavelets

31. Sequence of code assigned is called

Correct : A. Code Word

32. Every run length pair introduce new

Correct : D. Intensity

33. In the coding redundancy technique we use

Correct : D. Both A And B

34. Compression is done for saving

Correct : D. Both A And B

35. System of symbols to represent event is called

Correct : C. Code

36. Information lost when expressed mathematically is called

Correct : C. Fidelity Criteria

37. What does xml stand for?

Correct : B. Extensible Markup Language

38. What is the correct syntax of the declaration which defines the xml version?

Correct : B. <?Xml Version="A.0"?>

39. Which of the following programs support xml or xml applications?

Correct : D. Both A And B

40. Well formed xml document means

Correct : D. Must Contain One Or More Elements And Root Element Must Contain All Other Elements

41. Comment in xml document is given by

Correct : C. <!-- -->

42. Xml document can be viewed in

Correct : C. IE 6.0

43. How can we make attributes have multiple values

Correct : D. Attributes cannot have multiple values

44. Attribute standalone="no" should be included in xml declaration if a document

Correct : D. Has an external dtd

45. The xml dom object is

Correct : B. Entity Reference

46. Whats so great about xml?

Correct : D. Both A. & B.

47. The Attribute Used To Define A New Namespace Is

Correct : C. Xmlns

48. With XML:

Correct : D. With xml, all of the above are true.

49. An xml component that defines the structure of a document is known as a(n):

Correct : B. DTD

50. What is not true about xml?

Correct : A. Web Page Display Is The Most Important Application Of XML.

51. Data compression consists of taking a stream of symbols and transforming them into_______.

Correct : B. Codes

52. In Huffman coding, the actual output of the encoder is determined by a set of

Correct : A. Probabilities

53. A compression technique consists of two basic components such as

Correct : C. Encoding , Decoding

54. Advantages of data compression

Correct : A. The user can experience rich quality signals for data representation

55. Disadvantages of data compression

Correct : B. Compressed, sensitive data transmitted through a noisy communication channel is risky because the burst errors introduced by the noisy channel can destroy the transmitted data.

56. Lossy compression algorithm is applied to..

Correct : A. Images And Sound

57. Lossless compression algorithm is applied to..

Correct : C. Scientific Data

58. Example of entropy based compression is

Correct : A. RLE , Arithmetic , Huffman

59. Example of dictionary based compression is

Correct : B. Lempel-Ziv

60. Entropy coding can be used for

Correct : A. Sequence of digital data values

61. Entropy coding can be used for compression of any type of data in a

Correct : B. File system.

62. RLE Is Designed Especially For Data With

Correct : C. Strings of repeated symbols

63. Huffman coding is to find a way to compress the storage of data using

Correct : B. Variable Length Codes.

64. Huffman coding is constructed in such a way that no ___constructed code are prefixes to each other.

Correct : C. Two

65. Limitations of huffman coding is

Correct : A. Each symbol is encoded with integer number of bits

66. Arithmetic coding completely bypass the idea of replacing every input symbol with a

Correct : C. Codeword

67. The main aim of arithmetic coding is to assign the _____to each symbol.

Correct : A. Interval

68. Limitations of arithmetic coding

Correct : A. The precision required to represent the intervals grows with length of the message.

69. Arithmetic algorithms as well as huffman algorithms are based on

Correct : A. Statistical model

70. The lempel ziv algorithm is an algorithm for

Correct : A. Lossless data compression

71. Variations on lz77 scheme, like

Correct : C. LZSS, LZH And LZB

72. Lz77 exploits the fact that words and phrases within a ____would be repeated.

Correct : B. Text File

73. In LZ77 encoding process one reference (a triple) is transmitted for several input symbols and hence it is

Correct : C. Very Quick.

74. LZH is performed in ___ phases

Correct : A. Two

75. Regardless of the length of the phrase, every LZSS pointer is of

Correct : B. Same Size

76. LZB achieves a better compression than

Correct : C. LZSS

77. The decompression in LZ78 Is __compared to the process of compression.

Correct : B. Faster

78. LZW would only send the _____to the dictionary

Correct : B. Index

79. In arithmetic coding a ___identifier or tag is generated for the sequence to be encoded.

Correct : A. Unique

80. The use of the cumulative distribution function to generate a binary code for _____has a rather interesting history.

Correct : A. A Sequence

81. Once we have started decoding, all we have to do is ___the encoder algorithm.

Correct : A. Mimic

82. Advantage of arithmetic coding is that

Correct : A. It is easy to implement a system with multiple arithmetic codes

83. In file compression—unix once the dictionary has filled up, the size of the dictionary is ____to 1024 entries.

Correct : B. Doubled

84. GIF is another implementation of the ___ algorithm

Correct : A. LZW

85. GIF has become quite popular for encoding all kinds of images, both computergenerated and “___” images.

Correct : B. Natural

86. The PNG standard is one of the first standards to be collaboratively developed over the

Correct : B. Internet

87. PNG is based on

Correct : C. LZ77

88. The ITU-T recommendation V.42 bis is a compression standard devised for use over a

Correct : A. Telephone Network

89. Bwt algorithm requires that the entire sequence to be coded be available to the ____before the coding takes place

Correct : B. Encoder

90. Shannon Defined A Quantity Called

Correct : A. Self-Information

91. Models for certain telemetry data can also be obtained through ____of the underlying process.

Correct : A. Knowledge

92. Probability Models Know As..

Correct : C. Ignorance model

93. Markov process called

Correct : A. Discrete time markov chain

94. Markov models are more widely known

Correct : A. Finite context models

95. The ppm algorithms first attempt to find if the symbol to be encoded has a _____probability with respect to the maximum context length.

Correct : B. Nonzero

96. Composite source model, which can be viewed as a

Correct : B. Combination Or Composition Of Several Sources

97. The set of binary sequences is called a

Correct : A. Code

98. The set of binary sequences is called a code, and the individual members of the set are called

Correct : C. Codewords.

99. The ASCII code uses the same number of bits to represent each symbol. Such a code is called

Correct : B. Fixed-Length Code.

100. Unique decodability from the code; that is, any given sequence of codewords can be decoded in

Correct : B. One, And Only One, Way.