2 0 H a M e s i l a S t . , N e s h e r 3 6 8 8 5 2 0 , I s r a e l
P O B 2 5 0 0 4 , H a i f a 3 1 2 5 0 0 1 , I s r a e l
T e l : ( + 9 7 2 ) - 7 2 - 2 7 2 3 5 0 0 F a x : ( + 9 7 2 ) - 7 2 - 2 7 2 3 5 1 1
Page no. 40 | Appendix No. 1
8.11.13
lut_reset_red
Clears all red look up sample points.
8.11.14
lut_reset_green
Clears all green look up sample points.
8.11.15
lut_reset_blue
Clears all blue look up sample points.
8.11.16
lut_fun_rec709 <threshold> <linear-contrast> <linear-brightness> <contrast> <gamma>
<brightness>
Sets new LUT sample points according to REC.709 for selected LUT preset. Sets the gamma curve for all color
channels.
Value
Minimal
Maximal
REC.709
Threshold
0
1000
18
Contrast (linear)
0
20000
4500
Brightness (linear)
-1000
1000
0
Contrast (non-linear)
0
10000
1099
Gamma (non-linear)
1100
3000
2222
Brightness (nonlinear)
-1000
1000
-99
The following image shows the normalized REC.709 gamma curve and it's transition from linear to non-linear
(power function) part. The linear part ranges from 0 to <0.018 and is computed by the following formula:
V
out
= 4.5 ∗ V
in
The maximum value in this range is:
V
out,min
=
lim
V
in
→0.018
(4.5 ∗ V
in
) = 4.5 ∗ 0.018 = 0.081
The non-linear part ranges from 0.018 to 1 and is computed by the following formula:
V
out
= 1.099 ∗ V
in
(1/2.222)
− 0.099
The minimum value in this range is:
V
out,min
= 1.099 ∗ 0.018
(1/2.222)
− 0.099 = 0.081