Standard Codecs: Image Compression to Advanced Video Coding (IET Telecommunications Series)
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multiply all the luminance matrix elements by α = 50/25 = 2
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, and small elements of the matrix will be 1 and larger ones become 2. -
α = 0, hence all the matrix elements will be 1.
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the same as problem 1.
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62
0
3
1
0
0
1
0
0
1
-1
0
1
0
0
0
0
0
0
0
1
0
0
0
-1
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
3
-
31
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
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for 50% quality: DIFF = 62 - 50 = 12, symbol_1 = 4; symbol_2 = 12 scanned pairs (3,1)(0,3)(0,1)(0,-1)(1,-1)(6,1)(6,1)(1,1)(1,1)(35,3) and the resultant events:
(3,1)(0,2)(0,1)(0,1)(1,1)(6,1)(6,1)(1,1)(1,1)(15,0)(15,0)(3,3)
for 25% quality: DIFF= 31-50 = -19, symbol_1 = 5, symbol_2 = -19-1 =-20
scanned pairs: (4, 1)(57, 1)
events: (4,1)(15,0)(15,0)(15,0)(9,1)
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for DC: DIFF= -19 ⇒ CAT = 5; DIFF-1 = -20
VLC for CAT = 5 is 110 and -20 in binary is 11101100, hence the VLC for the DC coefficient is 11001100
for AC, using the AC VLC tables:
for each (15,0) the VLC is 11111111001
and for (9, 1) the VLC is 111111001
total number of bits: 8 + 3 x 11 + 9 = 50 bits.
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At bit-plane 6 coefficient 65 at clean-up pass. At bit-plane 5 coefficient 65 at all passes and coefficient 50 at clean-up pass.