APPARATUS FOR DIGITALLY FILTERING A VIDEO SIGNAL, AND RELATED METHOD

• US 20070046824A1
• Filed: 08/25/2006
• Published: 03/01/2007
• Est. Priority Date: 08/26/2005
• Status: Active Grant

• Current Assignee: Realtek Semiconductor Corp.
• Original Assignee: Realtek Semiconductor Corp.
• Inventors: Chen, Szu-Ping, Li, Kuo-Yang, Kung, Wen- Hsia
• Granted Patent: US 7,978,268 B2
• Time in Patent Office: Days
• US Class Current: 348/607
• CPC Class Codes: H04N 5/142 Edging; Contouring
• CPC Class Codes: H04N 5/21 Circuitry for suppressing or minimising disturbance, e.g. moiré or halo

Abstract

A method for digitally filtering a video signal comprises: converting the video signal into a plurality of sampled values; determining whether distribution of at least one portion of the sampled values belongs to one of a plurality of specific types according to the sampled values; and generating a plurality of output values according to a correction operation corresponding to the one of the specific types.

Claims

1. An apparatus for digitally filtering a video signal, comprising:

an analog-to-digital converter for converting the video signal into a plurality of sampled values; and

a correction circuit, coupled to the analog-to-digital converter, for determining whether distribution of at least one portion of the sampled values belongs to one of a plurality of specific types according to the sampled values, compensating the at least one portion of the sampled values according to a correction operation corresponding to the one of the specific types to generate a digital output signal corresponding to the video signal.

2. The apparatus of claim 1, wherein the specific types comprise a smear effect and a ringing effect.

3. The apparatus of claim 2, wherein the smear effect comprises a pulse smear effect and an edge smear effect.

4. The apparatus of claim 2, wherein the ringing effect comprises a rising edge ringing effect and a falling edge ringing effect.

5. The apparatus of claim 2, wherein the specific types further comprise a mismatch effect.

6. The apparatus of claim 1, wherein the specific types comprise a positive/negative pulse smear effect, a rising/falling edge smear effect, and a rising/falling edge ringing effect.

7. The apparatus of claim 1, wherein the sampled values comprise sequentially generated sampled values X(n−

1), X(n), and X(n+1), and the correction circuit identifies the type of the distortion according to the difference between the sampled values X(n−

1) and X(n) and the difference between the sampled values X(n) and X(n+1).

8. The apparatus of claim 1, wherein the correction operation comprises:

generating a compensation value according to at least two sampled values; and

compensating at least one of the sampled values according to the compensation value to generate an output value of the digital output signal.

9. A method for digitally filtering a video signal comprising:

converting the video signal into a plurality of sampled values;

determining whether distribution of at least one portion of the sampled values belongs to one of a plurality of specific types according to the sampled values;

and

generating a plurality of output values according to a correction operation corresponding to the one of the specific types.

10. The method of claim 9, wherein the sampled values comprise sequentially generated sampled values X(n−

1), X(n), and X(n+1), and the determining step further comprises;

identifying the type of the distortion according to the difference between the sampled values X(n−

1) and X(n) and the difference between the sampled values X(n) and X(n+1).

11. The method of claim 9, wherein the correction operation comprises:

generating a compensation value according to at least two sampled values; and

compensating at least one of the sampled values according to the compensation value to generate at least one of the output values.

12. The method of claim 9, wherein the specific types comprise a smear effect and a ringing effect.

13. The method of claim 12, wherein the smear effect comprises a pulse smear effect and an edge smear effect.

14. The method of claim 12, wherein the ringing effect comprises a rising edge ringing effect and a falling edge ringing effect.

15. The method of claim 12, wherein the specific types comprise a mismatch effect.

16. The method of claim 9, wherein the specific types comprise a positive/negative pulse smear effect, a rising/falling edge smear effect, and a rising/falling edge ringing effect.

17. A method for digitally filtering a video signal to generate an output video signal, the method comprising:

converting the video signal into a plurality of sampled values;

determining whether distribution of at least one portion of the sampled values belongs to one of a smear effect, a ringing effect, and a mismatch effect to produce an indication signal;

compensating the at least one portion of the sampled values according to a correction operation corresponding to the indication signal to produce a plurality of compensated values corresponding to the at least one portion of the sampled values; and

outputting the plurality of compensated values of the output video signal.