VIDEO SIGNAL EXTRACTING METHOD AND RELATED APPARATUS
A method and for extracting a chrominance signal of a video signal is disclosed. The method includes the following steps: generating a target video signal, a first delayed video signal, a second delayed video signal and a plurality of reference video signals; generating a HCS according to the target video signal; generating a VCS according to the target video signal and the plurality of reference video signals; generating a temporal chrominance signal; generating a SLFD according to the target video signal and the plurality of reference video signals; generating a weighting factor according to the target video signal, the second delayed video signal and the plurality of reference video signals; generating a spatial chrominance signal; and generating the chrominance signal of the video signal by determining the spatial chrominance signal, the temporal chrominance signal and the weighting factor.
This is a continuation-in-part of a co-pending U.S. patent application Ser. No. 10/708,706, which was filed on Mar. 19, 2004 and is included herein by reference.
BACKGROUNDThe invention relates to a video signal separator, and more particularly, to a method and related apparatus for separating a luminance signal from a video signal.
It has been over fifty years since color TVs were introduced to the public. A composite color TV signal (video signal in brief) for a color TV includes luminance as well as chrominance information. A luminance signal of the video signal works with frequencies ranging from 0 (DC) to 5.5 MHz, while a chrominance signal, which is carried by a carrier, works from 3.58 MHz to 4.43 MHz and overlaps the luminance signal. Numerous patents, such as U.S. Pat. No. 4,703,342, U.S. Pat. No. 4,954,885, U.S. Pat. No. 5,225,899, U.S. Pat. No. 5,231,477, U.S. Pat. No. 5,231,478, U.S. Pat. No. 5,386,244, U.S. Pat. No. 5,416,531, U.S. Pat. No. 5,416,532, U.S. Pat. No. 5,517,255, and EP0161923A2, have disclosed different methods and apparatus to separate the luminance signal from the video signal.
The ADC 12 samples the analog video signal with a sampling frequency fs, which is four times a color subcarrier fsc, and generates the DRVS, so chrominance signals of two adjacent sampling points have ninety degrees of phase difference. Since the color subcarrier fsc is equal to (455/2)fH, wherein fH is a horizontal scan frequency, which is equal to the amount of horizontal scan lines projected onto a screen 40 per second by a cathode tube of a color TV, chrominance signals of any sampling points on two adjacent horizontal scan lines have 180 degrees of phase difference.
Operations of the video signal separator 10 are described as follows: Please refer to
As the judging device 24 generates the select signal, the multiplexer 26 is capable of generating the chrominance signal according to the select signal. Then the subtractor 28 calculates the luminance signal by subtracting the chrominance from the video signal, that is, separating the luminance signal from the video signal.
The video signal separator 10 of the prior art has at least two drawbacks:
1. The judging device 24 of the video signal separator 10 depends on only three video signals (the DRVS, TVS and URVS) to generate the select signal. That the judging device 24 depends on only the TVS and two video signals respectively disposed upward and downward next to the TVS to generate the select signal is likely to generate a non-appropriate select signal and further calculates a false luminance signal and chrominance signal as well. For example, if the differences from the TVS to the upward as well as to the downward video signal are both significantly large while these two differences differs slightly from each other, the VLNC calculator 64 of the judging device 24 calculates a small VLNC and the judging circuit 68 transmits corresponding select signal to the multiplexer 26 according to the small VLNC, misleading the multiplexer 26 to output false luminance signal and chrominance signal.
2. The video signal separator 10 of the prior art generates the luminance signal as well as the chrominance signal in a so-called hard decision way—the multiplexer 26 only outputs one of the HRVS, TVS and VRVS as the luminance signal. When the non-correlated values respectively generated by the calculators 60, 62, 64 and 66 differs significantly from one another, the hard decision can calculate a luminance signal and a chrominance signal both with a tolerable error. However, when the non-correlated values generated by the calculators 60, 62, 64 and 66 are not significantly differ from one another, the select signal output from the judging device 24 by referring to these non-correlated values may mislead the multiplexer 26 to output improper luminance signal and chrominance signal.
SUMMARY OF THE INVENTIONIt is therefore an objective of the invention to provide a video signal separator and related apparatus capable of separating a luminance signal from a video signal of a video image displayed on a display device based on five horizontal scan lines and two frame delayed scan lines to overcome the drawbacks of the prior art.
According to an embodiment of the invention, a method for extracting a chrominance signal from a video signal is disclosed. The method comprises the following steps: generating a target video signal, a first delayed video signal, a second delayed video signal and a plurality of reference video signals by delaying the video signal; generating a horizontal chrominance signal (HCS) according to the target video signal; generating a vertical chrominance signal (VCS) according to the target video signal and the plurality of reference video signals; generating a temporal chrominance signal according to the target video signal and the first delayed video signal; generating a horizontal/vertical fading factor (SLFD) according to the target video signal and the plurality of reference video signals; generating a weighting factor according to the target video signal, the second delayed video signal and the plurality of reference video signals; generating a spatial chrominance signal by determining the HCS, the VCS, and the SLFD; and generating the chrominance signal of the video signal by determining the spatial chrominance signal, the temporal chrominance signal and the weighting factor.
According to another embodiment of the invention, a method for extracting a chrominance signal from a video signal is disclosed. The method comprising the following steps: generating a target video signal, a first delayed video signal, a second delayed video signal and a plurality of reference video signals by delaying the video signal; generating a horizontal chrominance signal (HCS) according to the target video signal; generating a vertical chrominance signal (VCS) according to the target video signal and the plurality of reference video signals; generating a horizontal/vertical fading factor (SLFD) according to the target video signal and the plurality of reference video signals; and generating the chrominance signal by determining the HCS, the VCS, and the SLFD.
According to another embodiment of the invention, a video signal processor for extracting a chrominance signal from a video signal provided. The video signal processor comprises a delay unit, a horizontal chrominance signal generator, a vertical chrominance signal generator, a temporal chrominance signal generator, a horizontal/vertical fading factor generator, a weighting factor generator, a spatial chrominance signal generator, and a chrominance signal generator. The delay unit is utilized for generating a target video signal, a first delayed video signal, a second delayed video signal, and a plurality of reference video signals by delaying the video signal; the horizontal chrominance signal generator is utilized for generating a horizontal chrominance signal (HCS) according to the target video signal; the vertical chrominance signal generator is utilized for generating a vertical chrominance signal (VCS) according to the target video signal and the plurality of reference video signal; the temporal chrominance signal generator is utilized for generating a temporal chrominance signal according to the target video signal and the first delayed video signal; the horizontal/vertical fading factor generator is utilized for generating a horizontal/vertical fading factor (SLFD) according to the target video signal and the plurality of reference video signals; the weighting factor generator is utilized for generating a weighting factor according to the target video signal, the second delayed video signal and the plurality of reference video signals; the spatial chrominance signal generator is utilized for generating a spatial chrominance signal according to the HCS, the VCS, and the SLFD; and the chrominance signal generator is utilized for generating the chrominance signal of the video signal according to the temporal chrominance signal, the spatial chrominance signal and the weighting factor.
According to another embodiment of the invention, a video signal processor for extracting a chrominance signal from a video signal is provided. The video signal comprises a delay unit, a horizontal chrominance signal generator, a vertical chrominance signal generator, a horizontal/vertical fading factor generator, and a chrominance signal generator. The delay unit is utilized for generating a target video signal and a plurality of reference video signals by delaying the video signal; the horizontal chrominance signal generator is utilized for generating a horizontal chrominance signal (HCS) according to the target video signal; the vertical chrominance signal generator is utilized for generating a vertical chrominance signal (VCS) according to the target video signal and the plurality of reference video signal; the horizontal/vertical fading factor generator is utilized for generating a horizontal/vertical fading factor (SLFD) according to the target video signal and the plurality of reference video signals; and the chrominance signal generator is utilized for generating a spatial chrominance signal according to the HCS, the VCS, and the SLFD.
It is an advantage of the invention that a video signal separator for separating a luminance signal from a video signal according to differences of a horizontal scan line and another four horizontal scan lines, and also according to differences of the horizontal scan line and another two frame delayed scan lines in soft decision can prevent an error that a judging device of the prior art video signal separator makes in determining a select signal from occurring.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
How the SLFD generator 84 generates the SLFD is described as follows: Please refer to
The Hdiff generator 87 of the SLDF generator 84 refers to an equation 3 (i.e., Hdiff=a*Dhy+(1−a)*Dhc) to calculate Hdiff while the Vdiff generator 89 of the SLDF generator 84 refers to an equation 4 (i.e., Vdiff=b*Dvy+(1−a)*Dvc) to calculate Vdiff. An “a” in the equation 3 and a “b” in the equation 4 are both weighting parameters and can be modified according to the video signal or to a TV system from which the video signal comes.
The process to generate Dhc, Dhy, Dvc and Dvy is described as follows: Please refer to
Please refer to
How the VCS generator 92 generates the Svc is described as follows: The VCS generator 92 includes a intermediate video signal generator 93 (IVS generator), an up/down fading factor generator 94 (UDFD generator) and a vertical reference video signal generator 96 (VRVS generator). IVS generator 93 generates a plurality of intermediate video signals according to the Sobj and the Sdn1, Sdn2, Sup1, and Sup2. IVS generator 93 also generates an upward chrominance signal (UCS) according to the Sobj and the Sup1, and a downward chrominance signal (DCS) according to the Sobj and the Sdn1. UDFD generator 94 calculates an UP/down fading factor UDFD according the plurality of intermediate video signals. VRVS generator 96 generates the Svc according to the UCS, the DCS and the UDFD, and Svc in reference to the equation of Svc=UDFD*UCS+(1−UDFD)*DCS.
How the IVS generator 93 of the VCS generator 92 generates the plurality of intermediate video signals is described as follows: Please refer to
Video signal generators 180, 182, 184 and 186 of the IVS generator 93 respectively include an adder 188, a multiplier 190, a subtractor 192 and a demodulator 194. The plurality of intermediate video signals Ssup1, Ssup2, Ssdn1 and Ssdn2 each includes a video luminance signal, a first chrominance signal heading to a first direction, and a second chrominance signal heading to a second direction, which is not parallel but usually perpendicular to the first direction.
How the plurality of video generators 180, 182, 184 and 186 generate a video luminance signal Ycu, a video first chrominance signal Ucu and a video second chrominance signal Vcu, all shown in
How the UDFD generator 94 of the VCS generator 92 generates the UDFD is described as follows:
In contrast to the prior art, this embodiment of the invention can provide a video signal separator, which is capable of calculating differences between a video signal located on a horizontal scan line and another four horizontal scan lines, and of then calculating a luminance signal and a chrominance signal of the video signal in soft decision based on the differences and these five horizontal scan lines, for preventing an error the judging device 24 of the prior art video signal separator 10 makes in determining the select signal from occurring. Additionally, the weighting parameters k, a and b in equation 1, 2 and 3 can be selectively modified to adapt to a video signal and a TV system in which the video system stays as well.
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Please refer to
The Hdiff generator 2842 of the SLDF generator 284 refers to the equation 3 (i.e., Hdiff=a*Dhy+(1−a)*Dhc) to calculate Hdiff while the Vdiff generator 2844 of the SLDF generator 284 refers to the equation 4 (i.e., Vdiff=b*Dvy+(1−a)*Dvc) to calculate Vdiff. An “a” in the equation 3 and a “b” in the equation 4 are both weighing parameters and can be modified according to the video signal or to a TV system from which the video signal comes.
Please note that, to utilize the horizontal interference calculator 2841 and the vertical interference calculator 2843 for generating Dhc, Dhy, Dvc and Dvy are similar to the above-mentioned horizontal interference calculator 86 and the vertical interference calculator 88 as shown in
The VCS generator 292 includes an intermediate video signal generator 2921 (IVS generator), an up/down fading factor generator 2922 (UDFD generator) and a vertical reference video signal generator 2923 (VRVS generator). IVS generator 2921 generates a plurality of intermediate video signals according to the Sobj and the Sdn1, Sdn2, Sup1 and Sup2. IVS generator 93 also generates an upward chrominance signal (UCS) according to the Sobj and the Sup1, and a downward chrominance signal (DCS) according to the Sobj and the Sdn1. UDFD generator 2922 calculates an UP/down fading factor UDFD according the plurality of intermediate video signals. And VRVS generator 2923 for generating the Svc according to the UCS, the DCS and the UDFD, and Svc in reference to the equation of Svc=UDFD*UCS+(1−UDFD)*DCS. Please note that, as the matter of fact that the VCS generator 292 is similar to the above-mentioned VCS generator 92 as shown in
Please refer to
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In addition, referring to the
Please note that, after the chrominance signal Sc is generated, the luminance signal generator 985 (LS generator) subtracts the chrominance signal Sc from the Sobj to generate the luminance signal Sy of the video signal. Accordingly, the chrominance signal Sc and the luminance signal Sy of the video signal can be extracted more precisely. Furthermore, the luminance signal generator 985 can be any type of luminance signal generator, and the detailed description is omitted here for brevity.
In contrast to the prior art, this embodiment of the invention can provide a video signal separator, which is capable of calculating differences between a video signal located on a horizontal scan line and another four horizontal scan lines, and calculating one difference between the video signal located on a horizontal scan line and one frame-delayed scan line and another difference between the video signal located on the horizontal scan line and another frame-delayed scan line, and then calculating a luminance signal and a chrominance signal of the video signal in soft decision based on the differences, these five horizontal scan lines, and the two frame delayed scan lines for preventing an error the judging device 24 of the prior art video signal separator 10 makes in determining the select signal from occurring. Additionally, the weighting parameters k, a and b in equation 1, 2 and 3 can be selectively modified to adapt to a video signal and a TV system in which the video system stays as well.
Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.
Claims
1. A method for extracting a chrominance signal from a video signal, the method comprising the following steps:
- (a) generating a target video signal, a first delayed video signal, a second delayed video signal and a plurality of reference video signals by delaying the video signal;
- (b) generating a horizontal chrominance signal (HCS) according to the target video signal;
- (c) generating a vertical chrominance signal (VCS) according to the target video signal and the plurality of reference video signals;
- (d) generating a temporal chrominance signal according to the target video signal and the first delayed video signal;
- (e) generating a horizontal/vertical fading factor (SLFD) according to the target video signal and the plurality of reference video signals;
- (f) generating a weighting factor according to the target video signal, the second delayed video signal and the plurality of reference video signals;
- (g) generating a spatial chrominance signal by determining the HCS, the VCS, and the SLFD; and
- (h) generating the chrominance signal of the video signal by determining the spatial chrominance signal, the temporal chrominance signal and the weighting factor.
2. The method of claim 1, wherein the step (c) comprises:
- (c1) generating an UDFD and a plurality of VRVSs according to the target video signal and the plurality of reference video signals; and
- (c2) generating the VCS according to the UDFD and the plurality of VRVSs.
3. The method of claim 2, wherein the plurality of reference video signals generated in step (a) comprises a first upward reference video signal (URVS), a second URVS, a first downward reference video signal (DRVS), and a second DRVS, the video signal being the second DRVS, the first DRVS lagged the video signal by a first predetermined numbers of scan lines, the target video signal lagged the first DRVS by the first predetermined numbers of scan lines, the first URVS lagged the target video signal by the first predetermined numbers of scan lines, and the second DRVS lagged the first URVS by the first predetermined numbers of scan lines, and step (c1) comprises the following steps:
- (h) generating a first upward video signal (UVS) according to the target video signal and the first URVS;
- (i) generating a second UVS according to the first URVS and the second URVS;
- (j) generating a first downward video signal (DVS) according to the target video signal and the first DRVS;
- (k) generating a second DVS according to the first DRVS and the second DRVS;
- (l) generating a Diffup according to the first UVS and the second UVS;
- (m) generating a Diffdn according to the first DVS and the second DVS; and
- (n) generating the UDFD according to the Diffup and the Diffdn.
4. The method of claim 3, wherein the UDFD is equal to Lim(Diffdn−Diffup), Lim( ) being a Sigmoid-like curve.
5. The method of claim 1, wherein the first delayed video signal is generated from delaying the target video signal by a second predetermined numbers of video frames, the second delayed video signal is generating from delaying the first delayed video signal by the second predetermined numbers of video frames, and step (f) comprises the following steps:
- generating a horizontal chrominance interfering factor (Dhc) and a horizontal luminance interfering factor (Dhy) according to the target signal and the reference signals;
- generating a horizontal difference (Hdiff) according to the Dhc and the Dhy;
- generating a vertical chrominance interfering factor (Dvc) and a vertical luminance interfering factor (Dvy) according to the target signal and the reference signals;
- generating a vertical difference (Vdiff) according to the Dvc and the Dvy; and
- generating the weighting factor according to the Hdiff, the Vdiff, the target signal, and the second delayed video signal.
6. The method of claim 1, wherein step (e) comprises the following steps:
- generating a horizontal chrominance interfering factor (Dhc) and a horizontal luminance interfering factor (Dhy) according to the target signal and the reference signals;
- generating a horizontal difference (Hdiff) according to the Dhc and the Dhy;
- generating a vertical chrominance interfering factor (Dvc) and a vertical luminance interfering factor (Dvy) according to the target signal and the reference signals;
- generating a vertical difference (Vdiff) according to the Dvc and the Dvy; and
- generating the SLFD according to the Hdiff and the Vdiff, wherein the SLFD is equal to Lim(k*Vdiff−Hdiff), Lim( ) being a Sigmoid-like curve, and k a weighting constant.
7. A method for extracting a chrominance signal from a video signal, the method comprising the following steps:
- (a) generating a target video signal, a first delayed video signal, a second delayed video signal and a plurality of reference video signals by delaying the video signal;
- (b) generating a horizontal chrominance signal (HCS) according to the target video signal;
- (c) generating a vertical chrominance signal (VCS) according to the target video signal and the plurality of reference video signals;
- (d) generating a horizontal/vertical fading factor (SLFD) according to the target video signal and the plurality of reference video signals; and
- (e) generating the chrominance signal by determining the HCS, the VCS, and the SLFD.
8. The method of claim 7, wherein step (d) comprises the following steps:
- generating a horizontal chrominance interfering factor (Dhc) and a horizontal luminance interfering factor (Dhy) according to the target signal and the reference signals;
- generating a horizontal difference (Hdiff) according to the Dhc and the Dhy;
- generating a vertical chrominance interfering factor (Dvc) and a vertical luminance interfering factor (Dvy) according to the target signal and the reference signals;
- generating a vertical difference (Vdiff) according to the Dvc and the Dvy; and
- generating the SLFD according to the Hdiff and the Vdiff, wherein the SLFD is equal to Lim(k*Vdiff−Hdiff), Lim( ) being a Sigmoid-like curve, and k a weighting constant.
9. The method of claim 7, wherein the plurality of reference video signals generated in step (a) comprises a first upward reference video signal (URVS), a second URVS, a first downward reference video signal (DRVS), and a second DRVS, the video signal being the second DRVS, the first DRVS lagged the video signal by a first predetermined numbers of scan lines, the target video signal lagged the first DRVS by the first predetermined numbers of scan lines, the first URVS lagged the target video signal by the first predetermined numbers of scan lines, and the second DRVS lagged the first URVS by the first predetermined numbers of scan lines.
10. A video signal processor for extracting a chrominance signal from a video signal comprising:
- a delay unit for generating a target video signal, a first delayed video signal, a second delayed video signal, and a plurality of reference video signals by delaying the video signal;
- a horizontal chrominance signal generator for generating a horizontal chrominance signal (HCS) according to the target video signal;
- a vertical chrominance signal generator for generating a vertical chrominance signal (VCS) according to the target video signal and the plurality of reference video signal;
- a temporal chrominance signal generator for generating a temporal chrominance signal according to the target video signal and the first delayed video signal;
- a horizontal/vertical fading factor generator for generating a horizontal/vertical fading factor (SLFD) according to the target video signal and the plurality of reference video signals;
- a weighting factor generator for generating a weighting factor according to the target video signal, the second delayed video signal and the plurality of reference video signals;
- a spatial chrominance signal generator for generating a spatial chrominance signal according to the HCS, the VCS, and the SLFD; and
- a chrominance signal generator for generating the chrominance signal of the video signal according to the temporal chrominance signal, the spatial chrominance signal and the weighting factor.
11. The video signal processor of claim 10, wherein the vertical chrominance signal generator comprises:
- a intermediate video signal generator (IVS generator) for generating an upward chrominance signal, a downward chrominance signal and a plurality of intermediate video signals according to the target video signal and the references,
- an UDFD generator, for generating a UDFD according to the plurality of intermediate video signals; and
- a VRVS generator, for generating the VCS according to the upward chrominance signal, the downward chrominance signal and the UDFD.
12. The video signal processor of claim 11, wherein the plurality of intermediate video signals comprises a first upward video signal (UVS), a second UVS, a first downward video signal (DVS) and a second DVS, the IVS generator comprising:
- a first UVS generator for generating the first UVS according to the target video signal and the first URVS;
- a second UVS generator for generating the second UVS according to the first URVS and the second URVS;
- a first DVS generator for generating the first DVS according to the target video signal and the first DRVS;
- a second DVS generator for generating the second DVS according to the first DRVS and the second DRVS;
- an upward chrominance signal generator for generating the upward chrominance signal according to the target video signal and the first URVS; and
- a downward chrominance signal generator for generating the downward chrominance signal according to the target video signal and the first DRVS; and
- the UDFD generator comprising:
- a Diffup generator for generating a upward difference (Diffup) according to the first UVS and the second UVS;
- a Diffdn generator for generating a downward difference (Diffdn) according to the first DVS and the second DVS; and
- a UDDM generator for generating the UDFD according to the Diffup and the Diffdn.
13. The video signal processor of claim 12, wherein the UDFD is equal to Lim(Diffdn−Diffup), Lim( ) being a Sigmoid-like curve.
14. The video signal processor of claim 12, wherein the first UVS comprises a Ycu, a Ucu heading to a first direction and a Vcu heading to a second direction, which is not parallel to the first direction, and the second UVS comprises a Yu, a Uu heading to the first direction and a Vu heading to the second direction, wherein Diffup is equal to ABS(Yu−Ycu)+SQRT((Uu−Ucu)2+(Vu−Vcu)2), ABS(x) being an absolute value of x, and SQRT(y) being a square root of y.
15. The video signal processor of claim 12, wherein the first DVS comprises a Ycd, a Ucd heading to a first direction and a Vcd heading to a second direction, which is not parallel to the first direction, and the second DVS comprises a Yd, a Ud heading to the first direction and a Vd heading to the second direction, wherein Diffdn is equal to ABS(Yd−Ycd)+SQRT((Ud−Ucd)2+(Vd−Vcd)2), ABS(x) being an absolute value of x, and SQRT(y) being a square root of y.
16. The video signal processor of claim 10, wherein the plurality of reference video signals comprises a first upward reference video signal (URVS), a second URVS, a first downward reference video signal (DRVS), and a second DRVS, the video signal being the second DRVS, the delay unit comprising:
- a first delay device for generating the first DRVS by delaying the video signal by a first predetermined numbers of scan lines;
- a second delay device for generating the target video signal by delaying the first DRVS by the first predetermined numbers of scan lines;
- a third delay device for generating the first URVS by delaying the target video signal by the first predetermined numbers of scan lines;
- a fourth delay device for generating the second DRVS by delaying the first URVS by the first predetermined numbers of scan lines;
- a first frame delay device for generating the first delayed video signal by delaying the target video signal by a second predetermined numbers of video frames; and
- a second frame delay device for generating the second delayed video signal by delaying the first delayed video signal by the second predetermined numbers of video frames.
17. The video signal processor of claim 16, wherein the horizontal/vertical fading factor generator comprises:
- a horizontal interference calculator for calculating a horizontal chrominance interfering factor (Dhc) and a horizontal luminance interfering factor (Dhy) according to the target video signal and the plurality of reference video signals;
- a vertical interference calculator for calculating a vertical chrominance interfering factor (Dvc) and a vertical luminance interfering factor (Dvy) according to the target video signal and the plurality of reference video signals;
- a horizontal difference generator for generating a horizontal difference (Hdiff) according to the Dhc and the Dhy;
- a vertical difference generator for generating a vertical difference (Vdiff) according to the Dvc and the Dvy; and
- a SLFD module for generating the SLFD according to the Hdiff and the Vdiff;
- wherein the SLFD is equal to Lim(k*Vdiff−Hdiff), Lim( ) being a Sigmoid-like curve, and k a weighing factor.
18. The video signal processor of claim 17, wherein the horizontal interference calculator comprises:
- a first adder for generating a first vertical luminance interfering signal by adding the URVS to the target video signal;
- a first 1-D comb filter for transferring the vertical luminance interfering signal into a first vertical luminance filtered signal;
- a second adder for generating a second vertical luminance interfering signal by adding the DRVS to the target video signal;
- a second 1-D comb filter for transferring the second vertical luminance interfering signal into a second vertical luminance filtered signal;
- a third adder for generating a vertical luminance signal by adding the first vertical luminance filtered signal to the second vertical luminance filtered signal;
- a first absoluter for transferring the vertical luminance signal into a positive vertical luminance signal;
- a first low pass filter for transferring the positive vertical luminance signal into the Dhy;
- a sample point delay circuit for generating a rightward reference video signal by delaying the target video signal by two sampling points;
- a subtractor for generating a horizontal chrominance interfering signal by subtracting the rightward reference video signal from the target video signal;
- a 2-D comb filter for transferring the horizontal chrominance interfering signal into a horizontal chrominance filtered signal;
- a second absoluter for transferring the horizontal chrominance filtered signal into a positive horizontal chrominance signal; and
- a second low pass filter for transferring the positive horizontal chrominance signal into the Dhc.
19. The video signal processor of claim 17, wherein the vertical interference calculator comprises:
- a first subtractor for generating a first vertical chrominance interfering signal by subtracting the URVS from the target video signal;
- a second subtractor for generating a second vertical chrominance interfering signal by subtracting the DRVS from the target video signal;
- a third subtractor for generating a vertical chrominance signal by subtracting the first vertical chrominance interfering signal from the second vertical chrominance interfering signal;
- a third absoluter for transferring the vertical chrominance signal into a positive vertical chrominance signal;
- a third low pass filter for transferring the positive vertical chrominance signal into the Dvc;
- a fourth adder for generating a first luminance interfering signal by adding a first rightward reference video signal to the URVS, the first rightward reference video signal lagging the URVS by twice an inverse of the sampling frequency;
- a fifth adder for generating a second horizontal luminance interfering signal by adding a second rightward reference video signal to the downward reference video signal, the second rightward reference video signal leading the DRVS by twice an inverse of the sampling frequency;
- a fourth subtractor for generating a horizontal luminance signal by subtracting the first horizontal luminance interfering signal from the second horizontal luminance interfering signal;
- a fourth absoluter for transferring the horizontal luminance signal into a positive horizontal luminance signal; and
- a fourth low pass filter for transferring the positive horizontal luminance signal into the Dvy.
20. The video signal processor of claim 17, wherein the weighting factor generator comprises:
- a second operator for processing the target video signal and the second delayed video signal to generate a temporal chrominance difference (Tdiff) between the target video signal and the second delayed video signal;
- a selecting module for selecting one of the Hdiff and the Vdiff to generate a SPdiff; and
- a third operator for generating the weighting factor according to the Tdiff and the SPdiff.
21. The video signal processor of claim 16, wherein the temporal chrominance signal generator comprises:
- a first operator for processing the target video signal and the first delayed video signal to generate the temporal chrominance signal.
22. A video signal processor for extracting a chrominance signal from a video signal comprising:
- a delay unit for generating a target video signal and a plurality of reference video signals by delaying the video signal;
- a horizontal chrominance signal generator for generating a horizontal chrominance signal (HCS) according to the target video signal;
- a vertical chrominance signal generator for generating a vertical chrominance signal (VCS) according to the target video signal and the plurality of reference video signal;
- a horizontal/vertical fading factor generator for generating a horizontal/vertical fading factor (SLFD) according to the target video signal and the plurality of reference video signals; and
- a chrominance signal generator for generating a spatial chrominance signal according to the HCS, the VCS, and the SLFD.
23. The video signal processor of claim 22, wherein the VCS generator comprises:
- a intermediate video signal generator (IVS generator) for generating an upward chrominance signal, a downward chrominance signal and a plurality of intermediate video signals according to the target video signal and the references,
- a UDFD generator, for generating a UDFD according to the plurality of intermediate video signals; and
- a VRVS generator, for generating the VCS according to the upward chrominance signal, the downward chrominance signal and the UDFD.
24. The video signal processor of claim 23, wherein the plurality of intermediate video signals comprising a first upward video signal (UVS), a second UVS, a first downward video signal (DVS) and a second DVS, the IVS generator comprising:
- a first UVS generator for generating the first UVS according to the target video signal and the first URVS;
- a second UVS generator for generating the second UVS according to the first URVS and the second URVS;
- a first DVS generator for generating the first DVS according to the target video signal and the first DRVS;
- a second DVS generator for generating the second DVS according to the first DRVS and the second DRVS;
- an upward chrominance signal generator for generating the upward chrominance signal according to the target video signal and the first URVS; and
- a downward chrominance signal generator for generating the downward chrominance signal according to the target video signal and the first DRVS; and
- the UDFD generator comprising:
- a Diffup generator for generating a upward difference (Diffup) according to the first UVS and the second UVS;
- a Diffdn generator for generating a downward difference (Diffdn) according to the first DVS and the second DVS; and
- a UDDM generator for generating the UDFD according to the Diffup and the Diffdn.
25. The video signal processor of claim 23, wherein the UDFD is equal to Lim(Diffdn−Diffup), Lim( ) being a Sigmoid-like curve.
26. The video signal processor of claim 23, wherein the first UVS comprises a Ycu, a Ucu heading to a first direction and a Vcu heading to a second direction, which is not parallel to the first direction, and the second UVS comprises a Yu, a Uu heading to the first direction and a Vu heading to the second direction, wherein Diffup is equal to ABS(Yu−Ycu)+SQRT((Uu−Ucu)2+(Vu−Vcu)2), ABS(x) being an absolute value of x, and SQRT(y) being a square root of y.
27. The video signal processor of claim 23, wherein the first DVS comprises a Ycd, a Ucd heading to a first direction and a Vcd heading to a second direction, which is not parallel to the first direction, and the second DVS comprises a Yd, a Ud heading to the first direction and a Vd heading to the second direction, wherein Diffdn is equal to ABS(Yd−Ycd)+SQRT((Ud−Ucd)2+(Vd−Vcd)2), ABS(x) being an absolute value of x, and SQRT(y) being a square root of y.
28. The video signal processor of claim 22, wherein the plurality of reference video signals comprises a first upward reference video signal (URVS), a second URVS, a first downward reference video signal (DRVS), and a second DRVS, the video signal being the second DRVS, the delay unit comprising:
- a first delay device for generating the first DRVS by delaying the video signal by a first predetermined numbers of scan lines;
- a second delay device for generating the target video signal by delaying the first DRVS by the first predetermined numbers of scan lines;
- a third delay device for generating the first URVS by delaying the target video signal by the first predetermined numbers of scan lines; and
- a fourth delay device for generating the second DRVS by delaying the first URVS by the first predetermined numbers of scan lines;
- a first frame delay device for generating the first delayed video signal by delaying the target video signal by a second predetermined numbers of video frames; and
- a second frame delay device for generating the second delayed video signal by delaying the first delayed video signal by the second predetermined numbers of video frames.
29. The video signal processor of claim 28, wherein the horizontal/vertical fading factor generator comprises:
- a horizontal interference calculator for calculating a horizontal chrominance interfering factor (Dhc) and a horizontal luminance interfering factor (Dhy) according to the target video signal and the plurality of reference video signals;
- a vertical interference calculator for calculating a vertical chrominance interfering factor (Dvc) and a vertical luminance interfering factor (Dhy) according to the target video signal and the plurality of reference video signals;
- a horizontal difference generator for generating a horizontal difference (Hdiff) according to the Dhc and the Dhy;
- an vertical difference generator for generating a vertical difference (Vdiff) according to the Dvc and the Dvy; and
- a SLFD module for generating the SLFD according to the Hdiff and the Vdiff;
- wherein the SLFD is equal to Lim(k*Vdiff−Hdiff), Lim( ) being a Sigmoid-like curve, and k a weighing factor.
30. The video signal processor of claim 29, wherein the horizontal interference calculator comprises:
- a first adder for generating a first vertical luminance interfering signal by adding the URVS to the target video signal;
- a first 1-D comb filter for transferring the vertical luminance interfering signal into a first vertical luminance filtered signal;
- a second adder for generating a second vertical luminance interfering signal by adding the DRVS to the target video signal;
- a second 1-D comb filter for transferring the second vertical luminance interfering signal into a second vertical luminance filtered signal;
- a third adder for generating a vertical luminance signal by adding the first vertical luminance filtered signal to the second vertical luminance filtered signal;
- a first absoluter for transferring the vertical luminance signal into a positive vertical luminance signal;
- a first low pass filter for transferring the positive vertical luminance signal into the Dhy;
- a sample point delay circuit for generating a rightward reference video signal by delaying the target video signal by two sampling points;
- a subtractor for generating a horizontal chrominance interfering signal by subtracting the rightward reference video signal from the target video signal;
- a 2-D comb filter for transferring the horizontal chrominance interfering signal into a horizontal chrominance filtered signal;
- a second absoluter for transferring the horizontal chrominance filtered signal into a positive horizontal chrominance signal; and
- a second low pass filter for transferring the positive horizontal chrominance signal into the Dhc.
31. The video signal processor of claim 29, wherein the vertical interference calculator comprises:
- a first subtractor for generating a first vertical chrominance interfering signal by subtracting the URVS from the target video signal;
- a second subtractor for generating a second vertical chrominance interfering signal by subtracting the DRVS from the target video signal;
- a third subtractor for generating a vertical chrominance signal by subtracting the first vertical chrominance interfering signal from the second vertical chrominance interfering signal;
- a third absoluter for transferring the vertical chrominance signal into a positive vertical chrominance signal;
- a third low pass filter for transferring the positive vertical chrominance signal into the Dvc;
- a fourth adder for generating a first luminance interfering signal by adding a first rightward reference video signal to the URVS, the first rightward reference video signal lagging the URVS by twice an inverse of the sampling frequency;
- a fifth adder for generating a second horizontal luminance interfering signal by adding a second rightward reference video signal to the downward reference video signal, the second rightward reference video signal leading the DRVS by twice an inverse of the sampling frequency;
- a fourth subtractor for generating a horizontal luminance signal by subtracting the first horizontal luminance interfering signal from the second horizontal luminance interfering signal;
- a fourth absoluter for transferring the horizontal luminance signal into a positive horizontal luminance signal; and
- a fourth low pass filter for transferring the positive horizontal luminance signal into the Dvy.
Type: Application
Filed: Dec 7, 2006
Publication Date: Jan 24, 2008
Inventors: Jen-Shi Wu (Hsin-Chu City), I-Hong Chen (Taoyuan City)
Application Number: 11/567,738
International Classification: H04N 9/77 (20060101); H04N 9/78 (20060101);