Digital video data quantization error detection as applied to intelligent dynamic companding

• US 5,335,019 A
• Filed: 01/14/1993
• Issued: 08/02/1994
• Est. Priority Date: 01/14/1993
• Status: Expired due to Term

• Current Assignee: Sony Electronics Inc. (Sony Group Corp.)
• Original Assignee: Sony Electronics Inc. (Sony Group Corp.)
• Inventors: Herz, William, Rossmere, David
• Primary Examiner(s): Powell, Mark R.
• Assistant Examiner(s): GRANT, CHRISTOPHER C
• Application Number:
  US08/004,687
• Time in Patent Office: 565 Days
• Field of Search: 358/160, 358/133, 358/166, 358/135, 358/136, 341/94, 341/95, 341/160, 375/122, 348/572, 348/573, 348/607, 348/639, 348/720, 371/47.1, 371/67.1
• US Class Current: 348/607
• CPC Class Codes: H04N 19/89 involving methods or arrangements for detection of transmission errors at the decoder
• CPC Class Codes: H04N 19/90 using coding techniques not provided for in groups H04N19/10-H04N19/85, e.g. fractals
• CPC Class Codes: H04N 5/20 Circuitry for controlling amplitude response
• CPC Class Codes: H04N 7/24 Systems for the transmission of television signals using pulse code modulation H04N21/00 takes precedence

Abstract

Under one embodiment, a first and a second similarly constituted detector, and an OR gate coupled to the two detectors, are provided to a digital video system. The first detector detects quantization errors of numerically adjacent values in vertically adjacent pixels of a current frame. The second detector detects quantization errors of numerically adjacent values in horizontally adjacent pixels in the current frame. The OR gate is used to determine whether quantization errors of numerically adjacent values are detected in at least one of the two spatial dimensions of pixel adjacency in the current frame. In one variation of this embodiment, a potential quantization error lookup table that supports concurrent lookups for vertically and numerically adjacent quantization error detection as well as horizontally and numerically adjacent quantization error detection is used and shared between the two detectors. In an expanded embodiment, a third similarly constituted detector is further provided, and coupled to the OR gate. The third detector detects quantization errors of numerically adjacent values in temporally adjacent pixels of successive frames. The OR gate is used to determine whether quantization errors of numerically adjacent values are detected in at least one of the three dimensions of pixel adjacency. In a further expanded embodiment, a compensation corrector is further provided, and coupled to the OR gate. The compensation corrector prevents successive shifting/modifying of digital video data of horizontally/vertically/temporally adjacent pixels to the same value otherwise resulting from dynamic companding.

Claims

1. In a digital video system comprising a plurality of digitized lines of video, an apparatus for detecting quantization errors of numerically adjacent values of digital video data of adjacent pixels in a dimension of pixel adjacency, said apparatus comprising:

a) first condition determination means for determining whether digital video data of a first and a second line of video have identical pixel values, said first and second lines of video being synchronized in said dimension of pixel adjacency;

b) second condition determination means for determining whether corresponding digital video data of said first and second lines of video are members of a list of input values (data_-- in) of a digital video data shifting/modifying function that cause quantization errors;

c) third condition determination means for determining whether corresponding digital video data of said first and second lines of video are numerically adjacent to each other; and

d) fourth condition determination means coupled to said first, second and third condition determination means for determining if quantization errors of numerically adjacent values exist for corresponding digital video data of said first and second lines of video based on the determination results of said first, second and third condition determination means.

2. The apparatus as set forth in claim 1, wherein,

said first condition determination means receives said first and second lines of video, determines whether digital video data of said first and second lines of video have identical pixel values, and outputs a logic one for a first condition signal (pid) if said digital video data of said first and second lines of video are determined as having different pixel values;

said second condition determination means receives said first and second lines of video, determines whether corresponding digital video data of said first and second lines of video are members of said list of data₁₃ in values of said digital video data shifting/modifying function that cause quantization errors, and outputs a logic one for a second condition signal (l1 ) and a logic one for a third condition signal (l2) if said corresponding digital video data of said first and second lines of video are determined to be members of said list respectively;

said third condition determination means receives said first and second lines of video, determines whether corresponding digital video data of said first and second lines of video are numerically adjacent to each other, and outputs a logic one for a fourth and a fifth condition signal (n1 and n2) if said corresponding digital video data of said first and second lines of video are determined to be numerically adjacent to each other;

said fourth condition determination means receives said pid, l1, l2, n1 and n2 condition signals, determines if all condition signals comprise logic ones in at least one combination of said pid, l1, l2 condition signals and a selected one of said n1 and n2 condition signals, and outputs a logic one for a sixth condition signal (QE) if all condition signals are determined to comprise logic ones for at least one combination of said pid, l1, l2 condition signals and a selected one of said n1 and n2 condition signals, indicating a quantization error of numerically adjacent values is detected for adjacent pixels in said dimension of pixel adjacency.

3. The apparatus as set forth in claim 2, wherein,

said first condition determination means comprise an XOR gate receiving said first and second lines of video, and outputting a logic one for said pid condition signal if said digital video data of said first and second lines of video have different pixel values;

said second condition determination means comprises a potential quantization error lookup table storing said list of data_-- in values of said digital video data shifting/modifying function that cause quantization errors receiving said first and second lines of video, and outputting a logic one for said l1 condition signal and a logic one for said l2 condition signal if said corresponding digital video data of said first and second lines of video are members of said list stored in said lookup table respectively;

said third condition determination means comprises an assembly of a first and a second incrementor and value equivalency lookup table pair receiving said first and second lines of video, said first incrementor and value equivalency lookup table pair outputting a logic one for said n1 condition signal if digital video data of said first line of video incremented by the incrementor of said first pair equals corresponding digital video data of said second line of video in accordance to said value equivalency lookup table of said first pair, said second incrementor and value equivalency lookup table pair outputting a logic one for said n2 condition signal if digital video data of said second line of video incremented by the incrementor of said second pair equals corresponding digital video data of said second line of video in accordance to the value equivalency table of said second pair;

said fourth condition determination means comprises an assembly of a first AND gate coupled to said XOR gate, said potential quantization error lookup table, and said first incrementor and value equivalency lookup table pair receiving said pid, l1, l2 and n1 condition signals, a second AND gate coupled to said XOR gate, said potential quantization error lookup table, and said second incrementor and value equivalency lookup table pair receiving said pid, l1, l2 and n2 condition signals, and an OR gate coupled to said first and second AND gates, said first AND gate outputting a logic one for a seventh condition signal (qe1) if said pid, l1, l2, and n1 condition signals comprise all logic ones, said second AND gate outputting a logic one for an eighth condition signal (qe2) if said pid, l1, l2, and n2 condition signals comprise all logic ones, said OR gate receiving said qe1 and qe2 condition signals and outputting a logic one for said QE condition signal if at least one of said qe1 and qe2 condition signal comprises a logic one.

4. The apparatus as set forth in claim 1, wherein,

said dimension of pixel adjacency is a vertical dimension of pixel adjacency,

said first condition determination means determines whether digital video data of a current line and a line delayed video have identical pixel values, said current line and line delayed video being synchronized in said vertical dimension of pixel adjacency;

said second condition determination means determines whether corresponding digital video data of said current line and line delayed video are members of said list of data_-- in values of said digital video data shifting/modifying function that cause quantization errors;

said third condition determination means determines whether corresponding digital video data of said current line and line delayed video are numerically adjacent to each other; and

said fourth condition determination means determines if quantization errors of numerically adjacent values exist for corresponding digital video data of said current line and line delayed video based on the determination results of said first, second and third condition determination means.

5. The apparatus as set forth in claim 1, wherein,

said dimension of pixel adjacency is a horizontal dimension of pixel adjacency,

said first condition determination means determines whether digital video data of a current line and a pixel delayed video have identical pixel values, said current line and pixel delayed video being synchronized in said horizontal dimension of pixel adjacency;

said second condition determination means determines whether corresponding digital video data of said current line and pixel delayed video are members of said list of data_-- in values of said digital video data shifting/modifying function that cause quantization errors;

said third condition determination means determines whether corresponding digital video data of said current line and pixel delayed video are numerically adjacent to each other; and

said fourth condition determination means determines if quantization errors of numerically adjacent values exist for corresponding digital video data of said current line and pixel delayed video based on the determination results of said first, second and third condition determination means.

6. The apparatus as set forth in claim 1, wherein,

said dimension of pixel adjacency is a temporal dimension of pixel adjacency,

said first condition determination means determines whether digital video data of a current line and a frame delayed video have identical pixel values, said current line and frame delayed video being synchronized in said temporal dimension of pixel adjacency;

said second condition determination means determines whether corresponding digital video data of said current line and frame delayed video are members of said list of data_-- in values of said digital video data shifting/modifying function that cause quantization errors;

said third condition determination means determines whether corresponding digital video data of said current line and frame delayed video are numerically adjacent to each other; and

said fourth condition determination means determines if quantization errors of numerically adjacent values exist for corresponding digital video data of said current line and frame delayed video based on the determination results of said first, second and third condition determination means.

36. The apparatus as set forth in claim 1, wherein, said apparatus further comprises:

e) compensation corrector means coupled to said fourth condition determination means for conditionally modifying said determinations made by said fourth condition determination means to prevent successive dynamic companding of input values (data_-- in) of said first and second lines of video to identical output values (data_-- out) said determinations made by said fourth condition determination means being used to selectively generate dynamic companding values for said digital video data of said first line of video.

37. The apparatus as set forth in claim 36, wherein,

said fourth condition determination means enables a quantization error detection condition signal (DRE) for said first line of video whenever determining said quantization errors of numerically adjacent values existed for corresponding digital video data of said first and second lines of video;

said digital video system further comprises a dynamic companding value generator coupled to said fourth condition determination means for selectively generating dynamic companding values (DCVs) for digital video data of said first line of video based on said DRE condition signal, a first frame memory coupled to said compensation corrector means for storing prior compensated quantization error detection indicator values (DRE'"'"'s) of said second line of video, and a second frame memory coupled to said dynamic companding value generator for storing prior selectively dynamic companded data_-- out values of said second line of video;

said compensation corrector means being further coupled to said dynamic companding value generator and said second frame of memory receives said DRE condition signal and DCVs of said first line of video, and said DRE'"'"'s and said selectively dynamic companded data_-- out values of said second line of video, determines if a plurality of compensation conditions exist based on said received DRE condition signal, DCVs, DRE'"'"'s, and selectively dynamic companded data_-- out values, and modifies said DRE condition signal based on said compensation condition determination results.

38. The apparatus as set forth in claim 37, wherein,

said compensation corrector modifies said DRE condition signal if

(e.c1) said DRE condition signal is enabled for a current pixel of said first line of video, and

(e.c2) said DRE'"'"' of the adjacent pixel in said second line of video is also enabled, and

(e.c3) said DCV of the adjacent pixel in said second line of video is the same as the DCV of said current pixel of said first line of video;

said compensation corrector modifies said DRE condition signal by disabling said enabled DRE condition signal.

7. In a digital video system comprising a plurality of digitized lines of video, a method for detecting quantization errors of numerically adjacent values of digital video data of adjacent pixels in a dimension of pixel adjacency, said method comprising the steps of:

a) determining whether digital video data of a first and a second line of video have identical pixel values, said first and second lines of video being synchronized in said dimension of pixel adjacency;

b) determining whether corresponding digital video data of said first and second lines of video are members of a list of input values (data_-- in) of a digital video data shifting/modifying function that cause quantization errors;

c) determining whether corresponding digital video data of said first and second lines of video are numerically adjacent to each other; and

d) determining if quantization errors of numerically adjacent values exist for corresponding digital video data of said first and second lines of video based on the determination results of said steps a) through c).

8. The method as set forth in claim 7, wherein,

said step a) comprises the steps of receiving said first and second lines of video, determining whether digital video data of said first and second lines of video have identical pixel values, and outputting a logic one for a first condition signal (pid) if said digital video data of said first and second lines of video are determined as having different pixel values;

said step b) comprises the steps of receiving said first and second lines of video, determining whether corresponding digital video data of said first and second lines of video are members of said list of data_-- in values of said digital video data shifting/modifying function that cause quantization errors, and outputting a logic one for a second condition signal (l1) and a logic one for a third condition signal (l2) if said corresponding digital video data of said first and second lines of video are determined to be members of said list respectively;

said step c) comprises the steps of receiving said first and second lines of video, determining whether corresponding digital video data of said first and second lines of video are numerically adjacent to each other, and outputting a logic one for a fourth and a fifth condition signal (n1 and n2) if said corresponding digital video data of said first and second lines of video are determined to be numerically adjacent to each other;

said step d) comprises the steps of receiving said pid, l1, l2, n1 and n2 condition signals, determining if all condition signals comprise logic ones in at least one combination of said pid, l1, l2 condition signals and a selected one of said n1 and n2 condition signals, and outputting a logic one for a sixth condition signal (QE) if all condition signals are determined to comprise logic ones for at least one combination of said pid, l1, l2 condition signals and a selected one of said n1 and n2 condition signals, indicating a quantization error of numerically adjacent values is detected for adjacent pixels in said dimension of pixel adjacency.

9. The method as set forth in claim 8, wherein,

said pid condition signal in said step a) is outputed by performing an XOR operation on pixel values of said first and second lines of video;

said l1 and l2 condition signals in said step b) are outputed by looking up corresponding digital video data of said first and second lines of video in a potential quantization error lookup table storing said list of data_-- in values of said digital video data shifting/modifying function that cause quantization errors;

said n1 and n2 condition signals of said step c) are outputed by incrementing digital video data of said first and second lines of video, and looking up said incremented digital video data of said first and second lines of video with their corresponding pre-increment digital video data of said second and first lines of video in value equivalency lookup tables;

said QE condition signal in said step d) is outputed by performing an 0R operation on a seventh and a eighth condition signal (qe1 and qe2), said qe1 condition signal being outputed by performing an AND operation on said pid, l1, l2 and n1 condition signals, said qe2 condition signal being outputed by performing an AND operation on said pid, l1, l2 and n2 condition signals.

10. The method as set forth in claim 7, wherein,

said dimension of pixel adjacency is a vertical dimension of pixel adjacency,

said step a) comprises the steps of determining whether digital video data of a current line and a line delayed video have identical pixel values, said current line and line delayed video being synchronized in said vertical dimension of pixel adjacency;

said step b) comprises the steps of determining whether corresponding digital video data of said current line and line delayed video are members of said list of data_-- in values of said digital video data shifting/modifying function that cause quantization errors;

said step c) comprises the steps of determining whether corresponding digital video data of said current line and line delayed video are numerically adjacent to each other; and

said step d) comprises the steps of determining if quantization errors of numerically adjacent values exist for corresponding digital video data of said current line and line delayed video based on the determination results of said steps a) through c).

11. The method as set forth in claim 7, wherein,

said dimension of pixel adjacency is a horizontal dimension of pixel adjacency,

said step a) comprises the steps of determining whether digital video data of a current line and a pixel delayed video have identical pixel values, said current line and pixel delayed video being synchronized in said horizontal dimension of pixel adjacency;

said step b) comprises the steps of determining whether corresponding digital video data of said current line and pixel delayed video are members of said list of data_-- in values of said digital video data shifting/modifying function that cause quantization errors;

said step c) comprises the steps of determining whether corresponding digital video data of said current line and pixel delayed video are numerically adjacent to each other; and

said step d) comprises the steps of determining if quantization errors of numerically adjacent values exist for corresponding digital video data of said current line and pixel delayed video based on the determination results of said steps a) through c).

12. The method as set forth in claim 7, wherein,

said dimension of pixel adjacency is a temporal dimension of pixel adjacency,

said step a) comprises the steps of determining whether digital video data of a current line and a frame delayed video have identical pixel values, said current line and frame delayed video being synchronized in said temporal dimension of pixel adjacency;

said step b) comprises the steps of determining whether corresponding digital video data of said current line and frame delayed line video are members of said list of data_-- in values of said digital video data shifting/modifying function that cause quantization errors;

said step c) comprises the steps of determining whether corresponding digital video data of said current line and frame delayed video are numerically adjacent to each other; and

said step d) comprises the steps of determining if quantization errors of numerically adjacent values exist for corresponding digital video data of said current line and frame delayed video based on the determination results of said steps a) through c).

13. The method as set forth in claim 7, wherein, said method further comprises the step of:

e) conditionally modifying said determinations made in said step d) to prevent successive dynamic companding of data_-- in values of said first and second lines of video to identical data_-- out values, said determinations made in said step d) being used to selectively generate dynamic companding values for said digital video data of said first line of video.

14. The method as set forth in claim 13, wherein,

said step d) comprises enabling a quantization error detection condition signal (DRE) for said first line of video whenever determining said quantization errors of numerically adjacent values existed for corresponding digital video data of said first and second lines of video;

said step e) comprises receiving said DRE condition signal of said first line of video, selectively generated dynamic companding values (DCVs) for digital video data of said first line of video based on said DRE condition signal, prior compensated quantization error detection indicator values (DRE'"'"'s) of said second line of video, and prior selectively dynamic companded data_-- out values of said second line of video, determining if a plurality of compensation conditions exist based on said received DRE condition signal, DCVs, DRE'"'"'s, and selectively dynamic companded data_-- out values, and modifying said DRE condition signal based on said compensation condition determination results.

15. The method as set forth in claim 14, wherein,

said DRE condition signal is modified in said step e) if

(e.c1) said DRE condition signal is enabled for a current pixel of said first line of video, and

(e.c2) said DRE'"'"' of the adjacent pixel in said second line of video is also enabled, and

(e.c3) said DCV of the adjacent pixel in said second line of video is the same as the DCV of said current pixel of said first line of video;

said DRE condition signal modification in said step e) comprises disabling said enabled DRE condition signal.

16. In a digital video system comprising a plurality of digitized lines of video, an apparatus for detecting quantization errors of numerically adjacent values of digital video data of adjacent pixels in a first and a second dimension of pixel adjacency, said apparatus comprising:

a) first detection means for detecting quantization errors of numerically adjacent values of digital video data of a first and a second line of video in said first dimension of pixel adjacency, said first and second lines of video being synchronized in said first dimension of pixel adjacency;

b) second detection means for detecting quantization errors of numerically adjacent values of digital video data of said first and a third line of video in said second dimension of pixel adjacency, said first and third lines of video being synchronized in said second dimension of pixel adjacency; and

c) third detection means coupled to said first and second detection means for detecting quantization errors of numerically adjacent values of corresponding digital video data of said first and second lines of video, and said first and third lines of video, based on the detection results of said first and second detection means.

17. The apparatus as set forth in claim 16, wherein,

said first detection means receives digital video data of said first and second lines of video, detects quantization errors of numerically adjacent values of corresponding digital video data of said first and second lines of video, and outputs a logic one for a first condition signal (QE1);

said second detection means receives digital video data of said first and third lines of video, detects quantization errors of numerically adjacent values of corresponding digital video data of said first and third lines of video, and outputs a logic one for a second condition signal (QE2); and

said third detection means receives said QE1 and QE2 condition signals, determines if at least one of said QE1 and QE2 condition signals comprises a logic one, and outputs an enabled third condition signal (DRE) if at least one of said QE1 and QE2 condition signals is determined to comprise a logic one, indicating a quantization error of numerically adjacent values is detected in adjacent pixels of said first and second dimensions of pixel adjacency.

18. The apparatus as set forth in claim 17, wherein, said third detection means comprises an OR gate receiving said QE1 and QE2 condition signals, and outputting said DRE condition signal.

19. The apparatus as set forth in claim 16, wherein,

said first and second dimensions of pixel adjacency are vertical and horizontal dimensions of pixel adjacency;

said first detection means detects quantization errors of numerically adjacent values of digital video data of a current line and a line delayed video in said vertical dimension of pixel adjacency, said current line and line delayed video being synchronized in said vertical dimension of pixel adjacency;

said second detection means detects quantization errors of numerically adjacent values of digital video data of said current line and a pixel delayed video in said horizontal dimension of pixel adjacency, said current line and pixel delayed video being synchronized in said horizontal dimension of pixel adjacency; and

said third detection means detects quantization errors of numerically adjacent values of corresponding digital video data of said current line and line delayed video, and said current line and pixel delayed video, based on the detection results of said first and second detection means.

20. The apparatus as set forth in claim 16, wherein,

said first and second dimensions of pixel adjacency are vertical and temporal dimensions of pixel adjacency;

said first detection means detects quantization errors of numerically adjacent values of digital video data of a current line and a line delayed video in said vertical dimension of pixel adjacency, said current line and line delayed video being synchronized in said vertical dimension of pixel adjacency;

said second detection means detects quantization errors of numerically adjacent values of digital video data of said current line and a frame delayed video in said temporal dimension of pixel adjacency, said current line and frame delayed video being synchronized in said temporal dimension of pixel adjacency; and

said third detection means detects quantization errors of numerically adjacent values of corresponding digital video data of said current line and line delayed video, and said current line and frame delayed video, based on the detection results of said first and second detection means.

21. The apparatus as set forth in claim 16, wherein,

said first and second dimensions of pixel adjacency are horizontal and temporal dimensions of pixel adjacency;

said first detection means detects quantization errors of numerically adjacent values of digital video data of a current line and a pixel delayed video in said horizontal dimension of pixel adjacency, said current line and pixel delayed video being synchronized in said horizontal dimension of pixel adjacency;

said second detection means detects quantization errors of numerically adjacent values of digital video data of said current line and a frame delayed video in said temporal dimension of pixel adjacency, said current line and frame delayed video being synchronized in said temporal dimension of pixel adjacency; and

said third detection means detects quantization errors of numerically adjacent values of corresponding digital video data of said current line and pixel delayed video, and said current line and frame delayed video, based on the detection results of said first and second detection means.

22. The apparatus as set forth in claim 16, wherein, said apparatus further comprises:

d) compensation corrector means coupled to said third detection means for conditionally modifying said detections made by said third detection means to prevent successive dynamic companding of input values (data_-- in) of said first and second lines of video, and said first and third lines of video, to identical output values (data_-- out) values, said detections made by said third detection means being used to selectively generate dynamic companding values for said digital video data of said first line of video.

23. The apparatus as set forth in claim 22, wherein,

said third detection means enables a quantization error detection condition signal (DRE) for said first line of video whenever detecting said quantization errors of numerically adjacent values existed for corresponding digital video data of said first and second lines of video, and said first and third lines of video;

said digital video system further comprises a dynamic companding value generator coupled to said third detection means for selectively generating dynamic companding values (DCVs) for digital video data of said first line of video based on said DRE condition signal, a first frame memory coupled to said compensation corrector means for storing prior compensated quantization error detection indicator values (DRE'"'"'s) of said second and third lines of video, and a second frame memory coupled to said dynamic companding value generator for storing prior selectively dynamic companded data_-- out values of said second and third lines of video;

said compensation corrector means being further coupled to said dynamic companding value generator and said second frame of memory receives said DRE condition signal and DCVs of said first line of video, and said DRE'"'"'s and said selectively dynamic companded data_-- out values of said second and third lines of video, determines if a plurality of compensation conditions exist based on said received DRE condition signal, DCVs, DRE'"'"'s, and selectively dynamic companded data_-- out values, and modifies said DRE condition signal based on said compensation condition determination results.

24. The apparatus as set forth in claim 23, wherein,

said compensation corrector modifies said DRE condition signal if

(d.c1) said DRE condition signal is enabled for a current pixel of said first line of video, and

(d.c2) said DRE'"'"' of at least one of the adjacent pixels in said second and third lines of video is also enabled, and

(d.c3) said DCV of the adjacent pixel is the same as the DCV of said current pixel of said first line of video for at least one of the cases where the DRE'"'"' of the adjacent pixel is also enabled;

said compensation corrector modifies said DRE condition signal by disabling said enabled DRE condition signal.

25. In a digital video system comprising a plurality of digitized lines of video, a method for detecting quantization errors of numerically adjacent values of digital video data of adjacent pixels in a first and a second dimension of pixel adjacency, said method comprising the steps of:

a) detecting quantization errors of numerically adjacent values of digital video data of a first and a second line of video in said first dimension of pixel adjacency, said first and second lines of video being synchronized in said first dimension of pixel adjacency;

b) detecting quantization errors of numerically adjacent values of digital video data of said first and a third line of video in said second dimension of pixel adjacency, said first and third lines of video being synchronized in said second dimension of pixel adjacency; and

c) detecting quantization errors of numerically adjacent values of corresponding digital video data of said first and second lines of video, and said first and third lines of video, based on the detection results of said first and second detection means.

26. The method as set forth in claim 25, wherein,

said step a) comprises the steps of receiving digital video data of said first and second lines of video, detecting quantization errors of numerically adjacent values of corresponding digital video data of said first and second lines of video, and outputting a logic one for a first condition signal (QE1);

said step b) comprises the steps of receiving digital video data of said first and third lines of video, detecting quantization errors of numerically adjacent values of corresponding digital video data of said first and third lines of video, and outputting a logic one for a second condition signal (QE2); and

said step c) comprises the steps of receiving said QE1 and QE2 condition signals, determining if at least one of said QE1 and QE2 condition signals comprises a logic one, and outputting an enabled third condition signal (DRE) if at least one of said QE1 and QE2 condition signals is determined to comprise a logic one, indicating a quantization error of numerically adjacent values is detected in adjacent pixels of said first and second dimensions of pixel adjacency.

27. The method as set forth in claim 26, wherein, said DRE condition signal in said step c) is outputed by performing an OR operation on said QE1 and QE2 condition signals.

28. The method as set forth in claim 25, wherein,

said first and second dimensions of pixel adjacency are vertical and horizontal dimensions of pixel adjacency;

said step a) comprises the steps of detecting quantization errors of numerically adjacent values of digital video data of a current line and a line delayed video in said vertical dimension of pixel adjacency, said current line and line delayed video being synchronized in said vertical dimension of pixel adjacency;

said step b) comprises the steps of detecting quantization errors of numerically adjacent values of digital video data of said current line and a pixel delayed video in said horizontal dimension of pixel adjacency, said current line and pixel delayed video being synchronized in said horizontal dimension of pixel adjacency; and

said step c) comprises the steps of detecting quantization errors of numerically adjacent values of corresponding digital video data of said current line and line delayed video, and said current line and pixel delayed video, based on the detection results of said steps a) and b).

29. The method as set forth in claim 25, wherein,

said first and second dimensions of pixel adjacency are vertical and temporal dimensions of pixel adjacency;

said step a) comprises the steps of detecting quantization errors of numerically adjacent values of digital video data of a current line and a line delayed video in said vertical dimension of pixel adjacency, said current line and line delayed video being synchronized in said vertical dimension of pixel adjacency;

said step b) comprises the steps of detecting quantization errors of numerically adjacent values of digital video data of said current line and a frame delayed video in said temporal dimension of pixel adjacency, said current line and frame delayed video being synchronized in said temporal dimension of pixel adjacency; and

said step c) comprises the steps of detecting quantization errors of numerically adjacent values of corresponding digital video data of said current line and line delayed video, and said current line and frame delayed line video, based on the detection results of said steps a) and b).

30. The method as set forth in claim 25, wherein,

said first and second dimensions of pixel adjacency are horizontal and temporal dimensions of pixel adjacency;

said step a) comprises the steps of detecting quantization errors of numerically adjacent values of digital video data of a current line and a pixel delayed video in said horizontal dimension of pixel adjacency, said current line and pixel delayed video being synchronized in said horizontal dimension of pixel adjacency;

said step b) comprises the steps of detecting quantization errors of numerically adjacent values of digital video data of said current line and a frame delayed video in said temporal dimension of pixel adjacency, said current line and frame delayed video being synchronized in said temporal dimension of pixel adjacency; and

said step c) comprises the steps of detecting quantization errors of numerically adjacent values of corresponding digital video data of said current line and pixel delayed video, and said current line and frame delayed video based on the detection results of said steps a) and b).

31. The method as set forth in claim 25, wherein, said method further comprises the step of:

d) conditionally modifying said detections in said step c) to prevent successive dynamic companding of input values (data_-- in) of said first and second lines of video to identical output values (data_-- out) said detections in said step c) being used to selectively generate dynamic companding values for said digital video data of said first line of video.

32. The method as set forth in claim 31, wherein,

said step c) comprises enabling a quantization error detection condition signal (DRE) for said first line of video whenever determining said quantization errors of numerically adjacent values existed for corresponding digital video data of said first and second lines of video, and said first and third lines of video;

said step d) comprises receiving said DRE condition signal of said first line of video, selectively generated dynamic companding values (DCVs) for digital video data of said first line of video based on said DRE condition signal, prior compensated quantization error detection indicator values (DRE'"'"'s) of said second and third lines of video, and prior selectively dynamic companded data_-- out values of said second and third lines of video, determining if a plurality of compensation conditions exist based on said received DRE condition signal, DCVs, DRE'"'"'s, and selectively dynamic companded data_-- out values, and modifying said DRE condition signal based on said compensation condition determination results.

33. The method as set forth in claim 32, wherein,

said DRE condition signal is modified in said step d) if

(d.c1) said DRE condition signal is enabled for a current pixel of said first line of video, and

(d.c2) said DRE'"'"' of the adjacent pixel in at least one of said second and third lines of video is also enabled, and

(d.c3) said DCV of the adjacent pixel is the same as the DCV of said current pixel of said first line of video for at least one of the cases where the DRE'"'"' of the adjacent pixel is also enabled;

said DRE condition signal modification in said step d) comprises disabling said enabled DRE condition signal.

34. In a digital video system comprising a plurality of digitized lines of video, an apparatus for detecting video conditions caused by video operations performed on numerically related values of digital video data of related pixels in a dimension of pixel relationship, said apparatus comprising:

a) first condition determination means for determining whether digital video data of a first and a second line of video are numerically related to each other in value in a first predetermined manner, said first and second lines of video being synchronized in said dimension of pixel relationship;

b) second condition determination means for determining whether corresponding digital video data of said first and second lines of video are members of a list of digital video data upon which when said video operations are performed, cause said video conditions;

c) third condition determination means for determining whether corresponding digital video data of said first and second lines of video are numerically related to each other in values in a second predetermined manner; and

d) fourth condition determination means coupled to said first, second and third condition determination means for determining if video conditions caused by video operations performed on numerically related values exist for corresponding digital video data of said first and second lines of video based on the determination results of said first, second and third condition determination means.

35. In a digital video system comprising a plurality of digitized lines of video, a method for detecting video conditions caused by video operations performed on numerically related values of digital video data of related pixels in a dimension of pixel relationship, said method comprising the steps of:

a) determining whether digital video data of a first and a second line of video are numerically related to each other in value in a first predetermined manner, said first and second lines of video being synchronized in said dimension of pixel relationship;

b) determining whether corresponding digital video data of said first and second lines of video are members of a list of digital video data upon which when said video operations are performed, cause said video conditions;

c) third condition determination means for determining whether corresponding digital video data of said first and second lines of video are numerically related to each other in value in a second predetermined manner; and

d) fourth condition determination means coupled to said first, second and third condition determination means for determining if video conditions caused by video operations performed on numerically related values exist for corresponding digital video data of said first and second lines of video based on the determination results of said first, second and third condition determination means.