quantization step (Δb)

DCT on the coefficients of approximations

DCT on the coefficients of details

CF (%)

PRD (%)

CF (%)

PRD (%)

10−4

97.02

27.7

97.39

26.82

10−5

92.76

0.29

93.72

2.75

10−6

87.56

0.03

88.24

0.28

10−7

86.67

27.05

87.03

0.03