Graphics Reference
In-Depth Information
1.1
1.05
1
Ideal
H.264/AVC
H.265/HEVC
0.95
0.9
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
Normalized frequency
Fig. 5.8
Comparison of magnitude response of half-pel interpolation filters of H.264/AVC and
HEVC relative to an ideal filter
A
−
1,
−
1
A
0,
−
1
a
0,
−
1
b
0,
−
1
c
0,
−
1
A
1,
−
1
A
2,
−
1
A
−
1,0
A
0,0
a
0,0
b
0,0
c
0,0
A
1,0
A
2,0
d
−
1,0
d
0,0
e
0,0
f
0,0
g
0,0
d
1,0
d
2,0
h
−
1,0
h
0,0
i
0,0
j
0,0
k
0,0
h
1,0
h
2,0
n
−
1,0
n
0,0
p
0,0
q
0,0
r
0,0
n
1,0
n
2,0
A
−
1,1
A
0,1
a
0,1
b
0,1
c
0,1
A
1,1
A
2,1
A
−
1,2
A
0,2
a
0,2
b
0,2
c
0,2
A
1,2
A
2,2
Fig. 5.9
Fractional positions used in luma motion compensation with 1/4 pixel accuracy
samples obtained by 6-tap FIR filter are first rounded to input bit-depth, prior
to using those for obtaining the quarter-pixel samples. To illustrate this effect,
let's consider interpolating the quarter-pixel sample a
0,0
using the H.264/AVC
interpolation process. In order to obtain a
0,0
, the half-pixel sample b
0,0
needs to
