Method and apparatus for video deinterlacing and format conversion

• US 20050134602A1
• Filed: 12/23/2003
• Published: 06/23/2005
• Est. Priority Date: 12/23/2003
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: LSI Logic Corporation (Broadcom, Inc.)
• Inventors: Linzer, Elliot N., Winger, Lowell L., Wells, Aaron G., Cote, Guy, Booth, Simon, Jia, Yunwei
• Granted Patent: US 7,362,376 B2
• Time in Patent Office: Days
• US Class Current: 345/606
• CPC Class Codes: H04N 5/142 Edging; Contouring
• CPC Class Codes: H04N 7/012 Conversion between an interlaced and a progressive signal for graphics images G09G2310/0229
• CPC Class Codes: H04N 7/0135 involving interpolation processes interpolation-based image scaling G06T3/4007; interpolation for video coding H04N19/587, H04N19/59
• CPC Class Codes: H04N 7/0142 the interpolation being edge adaptive edge detection in television signals H04N5/142; edge-driven scaling G06T3/403

Abstract

A method for deinterlacing a picture is disclosed. The method generally includes the steps of (A) generating a plurality of primary scores by searching along a plurality of primary angles for an edge in the picture proximate a location interlaced with a field of the picture, (B) generating a plurality of neighbor scores by searching for the edge along a plurality of neighbor angles proximate a particular angle of the primary angles corresponding to a particular score of the primary scores having a best value and (C) identifying a best score from a group of scores consisting of the particular score and the neighbor scores to generate an interpolated sample at the location.

Claims

1. A method for deinterlacing a picture, comprising the steps of:

(A) generating a plurality of primary scores by searching along a plurality of primary angles for an edge in said picture proximate a location interlaced with a field of said picture;

(B) generating a plurality of neighbor scores by searching for said edge along a plurality of neighbor angles proximate a particular angle of said primary angles corresponding to a particular score of said primary scores having a best value; and

(C) identifying a best score from a group of scores consisting of said particular score and said neighbor scores to generate an interpolated sample at said location.

2. The method according to claim 1, further comprising the step of:

calculating said interpolated sample at said location by directional filtering said field along a best angle corresponding to said best score, said best angle belonging to a group of angles consisting of said particular angle and said neighbor angles.

3. The method according to claim 1, wherein said primary angles comprise six angles within a 180 degree range.

4. The method according to claim 3, wherein said neighbor angles consist of two angles, one on each side of said particular angle.

5. The method according to claim 1, wherein said primary angles are evenly separated from each other.

6. A method for deinterlacing a picture, comprising the steps of:

(A) determining an intra-mode angle from an intra-mode estimation of a block in said picture;

(B) generating a plurality of samples for said block in based on said intra-mode estimation; and

(C) calculating an interpolated sample at a location interlaced with said block by directional filtering said samples along said intra-mode angle.

7. The method according to claim 6, further comprising the step of:

searching for a particular angle corresponding to an edge in said picture proximate said location.

8. The method according to claim 7, further comprising the step of:

blending said intra-mode angle with said particular angle prior to calculating said interpolated sample.

9. The method according to claim 6, wherein said block comprises a field block.

10. The method according to claim 6, further comprising the step of:

calculating said interpolated sample at said location interlaced with said block by vertical filtering said samples in response to a low confidence value for said intra-mode angle.

11. A method for deinterlacing a picture, comprising the steps of:

(A) searching for an edge in said picture proximate a location interlaced with a field of said picture;

(B) calculating an interpolated sample at said location by vertically filtering said field using a first tap filter having a first number of taps in response to not finding said edge; and

(C) calculating said interpolated sample by directionally filtering said field along a particular angle corresponding to said edge using a second tap filter having a second number of taps less than said first number of taps in response to finding said edge.

12. The method according to claim 11, wherein said second tap filter comprises a bilinear filter.

13. The method according to claim 11, wherein step (A) comprises a sub-step of:

marking said edge as one of found and not found based on said confidence level generated for said edge.

14. The method according to claim 13, wherein said confidence level is determined by two parameters calculated for said edge.

15. The method according to claim 14, wherein one of said two parameters includes a penalty value as a function of said particular angle.

16. A method for deinterlacing a picture, comprising the steps of:

(A) searching a region proximate a location interlaced with a first field said picture for an aperture in said picture;

(B) calculating an interpolated sample at said location by directional filtering said first field in response to not finding said aperture; and

(C) calculating said interpolated sample at said location by vertical filtering said first field in response to finding said aperture.

17. The method according to claim 16, wherein step (C) comprises the sub-step of:

calculating said interpolated sample at said location by both vertical filtering said first field and temporal blending said first field with a second field.

18. The method according to claim 16, wherein step (A) comprises the sub-steps of:

evaluating a first line in said first field immediately above said location for said aperture; and

evaluating a second line in said first field immediately below said location for said aperture.

19. The method according to claim 18, wherein each step of evaluating comprises the sub-steps of:

calculating a center value around said location;

calculating a left value to a left of said location; and

calculating a right value to a right of said location.

20. The method according to claim 19, wherein each step of evaluating further comprises the sub-steps of:

comparing said left value against said center value; and

comparing said right value against said center value.