1. An information recording andor reproducing apparatus, comprising:
an optical head for emitting a light beam on a medium and receiving a reflected light beam from the medium, a tilt is defined by a deviation of the angle of the light beam from the medium;
an analog signal processor for processing the reflected light beam to obtain a first analog signal;
an analogdigital converter for converting the first analog signal into a digital signal;
a controller for applying a low-pass filtering operation on the digital signal to obtain a digital controlling signal;
a digitalanalog converter for converting the digital controlling signal into a second analog signal; and
an adjustment mechanism for adjusting a position of the optical head to correct the tilt according to the second analog signal;
wherein the controller comprises a first calculator for applying a first low-pass filtering operation on the digital signal, the first calculator performing a function of:
C1(z)=(K1*A(z)+K2)(A(z)\u2212K3)
wherein C1(z) represents a signal which is outputted by the first calculator after applying the first low-pass filtering operation on the digital signal, A(z) is the digital signal which is a variable parameter and represents an input signal of the first calculator, K1, K2, and K3 are constant parameters of the first calculator, and z represents a frequency of the first analog signal.
2. The information recording andor reproducing apparatus as claimed in claim 1, wherein the constant parameters K1=0.2108, K2=0.2108, and K3=0.5784.
3. The information recording andor reproducing apparatus as claimed in claim 1, further comprising a second calculator for applying a second low-pass filtering operation on the C1(z), the second calculator performing a function of:
C2(z)=(M1*C1(z)+M2)(C1(z)\u2212M3)
wherein C2(z) represents a signal which is outputted by the second calculator after applying the second low-pass filtering operation on the C1(z), M1, M2, and M3 are constant parameters of the second calculator.
4. The information recording andor reproducing apparatus as claimed in claim 3, wherein the constant parameters M1=0.0186, M2=0.0, and M3=0.0.
5. The information recording andor reproducing apparatus as claimed in claim 3, further comprising a third calculator for applying a third low-pass filtering operation on the C2(z), the third calculator performing a function of:
C3(z)=(C2(z)+N1)(C2(z)\u2212N2)
wherein C3(z) represents a signal which is outputted by the third calculator after applying the third low-pass filtering C2(z), N1, and N2 are constant parameters of the third calculator.
6. The information recording andor reproducing apparatus as claimed in claim 5, wherein the constant parameters N1=0.0063, N2=0.9824.
7. The information recording andor reproducing apparatus as claimed in claim 1, wherein the controller comprises an amplifier for amplifying the digital signal inputted to the controller.
8. The information recording andor reproducing apparatus as claimed in claim 7, wherein an amplification coefficient of the amplifier is set to a value of 0.6250.
9. A tilt detecting device for detecting a tilt detecting signal, the tilt detecting signal being relative to a tilt defined by a deviation of a light beam from a medium, the light beam emitted on the medium by an optical head, the tilt detecting device comprising:
a first calculator for applying a first low-pass filtering operation on a digital signal corresponding to a reflected light beam from the medium, the first calculator performing a function of:
C1(z)=(K1*A(z)+K2)(A(z)\u2212K3)
wherein C1(z) represents a signal which is outputted by the first calculator after applying the first low-pass filtering operation on the digital signal, A(z) is the digital signal which is a variable parameter and represents an input signal of the first calculator, K1, K2, and K3 are constant parameters of the first calculator, and z represents a frequency of the first analog signal; and
a second calculator for applying a second low-pass filtering operation on the C1(z) to obtain the tilt detecting signal, the second calculator performing a function of:
C2(z)=(M1*C1(z)+M2)(C1(z)\u2212M3)
wherein C2(z) represents the tilt detecting signal which is outputted by the second calculator after applying the second low-pass filtering operation on the C1(z), M1, M2, and M3 are constant parameters of the second calculator.
10. The tilt detecting device as claimed in claim 9, wherein the constant parameters K1=0.2108, K2=0.2108, and K3=0.5784.
11. The tilt detecting device as claimed in claim 9, wherein the constant parameters M1=0.0186, M2=0.0, and M3=0.0.
12. The tilt detecting device as claimed in claim 9, further comprising a third calculator for applying a third low-pass filtering operation on the C2(z) to obtain the tilt detecting signal, the third calculator performing a function of:
C3(z)=(C2(z)+N1)(C2(z)\u2212N2)
wherein C3(z) represents the tilt detecting signal which is outputted by the third calculator after applying the third low-pass filtering operation on the C2(z), N1, and N2 are constant parameters of the third calculator.
13. The tilt detecting device as claimed in claim 12, wherein the constant parameters N1=0.0063, N2=0.9824.
14. The tilt detecting device as claimed in claim 9, further comprising an amplifier for amplifying the digital signal inputted to the controller, and an amplification coefficient of the amplifier is set to a value of 0.6250.
15. A tilt detecting method for detecting a tilt detecting signal, the tilt detecting signal being relative to a tilt defined by a deviation of a light beam from a medium, the light beam emitted on the medium by an optical head, the tilt detecting method comprising steps of:
receiving a reflected light beam from the medium;
converting the reflected light beam into an electrical signal;
converting the electrical signal into a digital signal;
applying a first low-pass filtering operation on the digital signal, the step implemented by a first calculator, the first calculator performing a function of:
C1(z)=(K1*A(z)+K2)(A(z)\u2212K3)
wherein C1(z) represents a signal which is outputted by the first calculator after applying the first low-pass filtering operation on the digital signal, A(z) is the digital signal which is a variable parameter and represents an input signal of the first calculator, K1, K2, and K3 are constant parameters of the first calculator, and z represents a frequency of the first analog signal; and
applying a second low-pass filtering operation on the C1(z) to obtain the tilt detecting signal, the step implemented by a second calculator, the second calculator performing a function of:
C2(z)=(M1*C1(z)+M2)(C1(z)\u2212M3)
wherein C2(z) represents the tilt detecting signal which is outputted by the second calculator after applying the second low-pass filtering operation on the C1(z), M1, M2, and M3 are constant parameters of the second calculator.
16. The tilt detecting method as claimed in claim 15, further comprising a step of processing the electrical signal to obtain an analog signal that is then converted to the digital signal.
17. The tilt detecting method as claimed in claim 15, further comprising a step of amplifying the digital signal before the step of applying the first low-pass filtering operation.
18. The tilt detecting method as claimed in claim 15, further comprising a step of applying a third low-pass filtering operation on the C2(z) to obtain the tilt detecting signal, the step implemented by a third calculator, the third calculator performing a function of:
C3(z)=(C2(z)+N1)(C2(z)\u2212N2)
wherein C3(z) represents the tilt detecting signal which is outputted by the third calculator after applying the third low-pass filtering operation on the C2(z), N1, and N2 are constant parameters of the third calculator.
19. The tilt detecting method as claimed in claim 15, wherein the constant parameters K1=0.2108, K2=0.2108, and K3=0.5784.
20. The tilt detecting method as claimed in claim 15, wherein the constant parameters M1=0.0186, M2=0.0, and M3=0.0.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for encoding at least one picture having a first region and a second region wherein
the first region is encoded according to a first encoding scheme,
the second region is encoded according to a second encoding scheme,
the second encoding scheme is carried out taking into account a parameter representing the visual perception of the second region.
2. The method according to claim 1, wherein the first encoding scheme is carried out not taking the parameter into account.
3. The method according to claim 1, wherein the second region is formed by a perceptual region-of-interest representation.
4. The method according to claim 3, wherein a simplified perceptual quality significance map is determined from the perceptual region-of interest representation.
5. The method according to claim 1, wherein quantization parameters used for encoding the second region are adjusted according to the parameter.
6. The method according to claim 5, wherein the quantization step is determined according to the equation
Q
\u2061
(
x
,
y
)
=
a
1
\xb7
Q
init
P
\u2061
(
x
,
y
)
,
where a1 is a constant, Qinit is an initial quantization step and P(x,y) is a simplified perceptual quality significance map.
7. The method according to claim 1, wherein the shifting values used for encoding the second region are adjusted according to the parameter.
8. The method according to claim 7, wherein the shifting values are determined according to the formula S(x, y)=P(x, y) wherein P(x,y) is a simplified perceptual quality significance map.
9. Encoder for encoding a picture with a first region and a second region wherein the encoder comprises
a first encoding unit encoding the first region
a second encoding unit encoding the second region wherein
the second encoding unit takes a parameter representing the visual perception of the second region into account when encoding the second region.
10. A non-transitory computer readable medium storing a program, which, when executed by a computer, makes the computer perform a method for encoding a picture with a first region and a second region wherein
the first region is encoded according to a first encoding scheme
the second region is encoded according to a second encoding scheme
the second encoding scheme is carried out taking a parameter representing the visual perception of the second region into account.