Chapter 3

    1. |x| 16; y = 0 16 < |x| 32; y = ±24 32 < |x| < 48; y = ±40 etc.

    2. |x| 16; y = ±8 16 < |x| 32; y = ±24 32 < |x| 48; y = ±40 etc.

  1. 12 16 28 240 196 32 PSNR = 43.4 dB

  2. 6 12 27 77 127 77 PSNR = 10.7 dB

  3. 15 21 19 21 19 69 119 169 219 234 232 230 232 230

    click to expand

  4. click to expand

    1. 364 15 -211 -26 -5 38 -2 -1

    2. the basis vector of the second AC coefficient matches the input pixels

    3. 35 82 190 250 200 150 101 23. Due to mismatch (approximating the cosine elements) some of the input pixels cannot be reconstructed, e.g. 81/82 and 100/101.

  5. quantised coefficients:

    360

    0

    -216

    -24

    0

    40

    0

    0

    reconstructed pixels: PSNR = 30 dB

    30

    70

    185

    250

    204

    153

    104

    27

    1. reconstructed pixels: PSNR = 10.4 dB

    128

    128

    128

    128

    128

    128

    128

    128

    1. reconstructed pixels: PSNR = 23.4 dB

    28

    87

    169

    227

    227

    169

    87

    28

    1. mv(-1, -1)

    2. mv(-1, -1)

    1. 169

      1. multiplications = 256 × 169, additions = 511 × 169

      2. multiplications = 0, additions = 511 × 169

  6. type

    operations

    Multiplications

    additions

    TDL

    23

    23 × 256

    23 × 511

    TSS

    25

    25 × 256

    25 × 511

    CSA

    17

    17 × 256

    17 × 511

    OSA

    13

    13 × 256

    13 × 511

    1. = 010,

    2. = 1,

    3. = 00,

    4. = 011, av bits = 1.8, entropy = 1.72

    1. cbdad = 001011010011

      1. 1st bit in error decoded string = babbad

      2. 3rd bit in error, decoded string = ccbbad

      3. 5th bit in error, decoded string = cbcbad

  7. lower value = 0.83875, upper value = 0.841875

    1. the first three symbols = cbc

    2. the first five symbols = cbcab

  8. the same as 15

  9. 11010110111

  10. the same as 17

    1. first bit in error = 0.01010110111 = 2-2 + 2-4 + 2-6 + 2-7 +2-9 + 2-10 + 2-11 = 0.33935546875 which is decoded to string bbacb

    2. similarly, with the third bit in error the decimal number would be 0.96435546875, decoded to dbacb

    3. with the fifth bit in error, the decimal number is 0.87060546875 and it is decoded to string cbacb.



Standard Codecs(c) Image Compression to Advanced Video Coding
Standard Codecs: Image Compression to Advanced Video Coding (IET Telecommunications Series)
ISBN: 0852967101
EAN: 2147483647
Year: 2005
Pages: 148
Authors: M. Ghanbari

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