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7.4 Experimental Results and Observations 145
related to its neighboring blocks of lifting angles α
n
, α
w
, and α
d
, we predict the
optimal lifting direction ϑ to be
ˆ
ϑ =
α
w
| α
d
−α
w
|>| α
d
−α
n
|
α
n
| α
d
−α
w
|≤| α
d
−α
n
|
. (7.17)
Then, the prediction error e
ϑ
= ϑ −
ˆ
ϑ is arithmetic coded. The coded segment struc-
ture and predicted angle error are embedded in the user data part of JPEG 2000.
If v ∈ S is an internal node, then r
T
(v) = 1, that is, the bit to indicate the event
of splitting the corresponding block; otherwise, for each leaf node τ ∈S,r
T
(τ) is the
number of bits to code the coefficients h
τ,ϑ
(m,n) in node τ and the optimal direction
ϑ of the ADL, plus one bit to signal the terminal node. The rate of coding is estimated
by the entropy of ADL coefficients ...