Graphics Reference
In-Depth Information
P or Q is intra?
No
P or Q has
non-zero
coefficients?
No
P and Q
use different ref.
pictures?
No
Abs. difference
between P and Q's
MVs is ≥1 integer
sample?
No
BS = 2
Bs = 1
Bs = 0
Fig. 7.5
Derivation of boundary strength (
Bs
) for block boundary. P denotes the left (or top) block
and Q denotes the right (or bottom) block at the block boundary
oo o o
oo o o
oo o o
oo o o
q
0,0
q
1,0
q
2,0
q
3,0
oo o o
oo o o
oo o o
oo o o
oo o o
oo o o
oo o o
oo o o
p
3,0
p
2,0
p
1,0
p
0,0
q
0,1
q
1,1
q
2,1
q
3,1
p
3,1
p
2,1
p
1,1
p
0,1
p
3,2
p
2,2
p
1,2
p
0,2
q
0,2
q
1,2
q
2,2
q
3,2
p
3,3
p
2,3
p
1,3
p
0,3
q
0,3
q
1,3
q
2,3
q
3,3
oo o o
oo o o
oo o o
oo o o
oo o o
oo o o
oo o o
oo o o
oo o o
oo o o
oo o o
oo o o
Block P
Block Q
Fig. 7.6
Four-sample segment of vertical block boundary between adjacent blocks P and Q.
Deblocking decision are made based on lines 0 and 3 (
dashed
)
j
p
2;0
2p
1;0
C
p
0;0
j C j
p
2;3
2p
1;3
C
p
0;3
j
C j
q
2;0
2q
1;0
C
q
0;0
j C j
q
2;3
2q
1;3
C
q
0;3
j
<“;
(7.1)
where the threshold “ depends on the quantization parameters QP and is derived
from a look-up table. Equation (
7.1
) is used to check how much the signal on each
side of the block boundary deviates from a straight line (ramp). The equations in
this topic chapter are given for the case of a vertical block boundary as in Fig.
7.6
.
The equations for a horizontal block boundary may be obtained from the equations
for the vertical boundary by swapping the row and column indices.
