Region-based information compaction as for digital images

• US 20030202589A1
• Filed: 05/06/2003
• Published: 10/30/2003
• Est. Priority Date: 03/30/1998
• Status: Active Grant

• Current Assignee: DigiMedia Tech, LLC (IP Investments Group LLC)
• Original Assignee: Akikaze Technologies, LLC
• Inventors: Reitmeier, Glenn Arthur, Tinker, Michael
• Granted Patent: US 7,403,565 B2
• Time in Patent Office: Days
• US Class Current: 375/240.12
• CPC Class Codes: H04N 19/46 Embedding additional information in the video signal during the compression process H04N19/517, H04N19/68, H04N19/70 take precedence
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 19/85 using pre-processing or post-processing specially adapted for video compression
• CPC Class Codes: H04N 19/98 Adaptive-dynamic-range coding [ADRC]
• CPC Class Codes: H04N 21/234345 the reformatting operation being performed only on part of the stream, e.g. a region of the image or a time segment
• CPC Class Codes: H04N 21/23614 Multiplexing of additional data and video streams arrangements for simultaneous broadcast of plural pieces of information H04H20/28
• CPC Class Codes: H04N 21/4348 Demultiplexing of additional data and video streams
• CPC Class Codes: H04N 21/440245 the reformatting operation being performed only on part of the stream, e.g. a region of the image or a time segment

Abstract

A method and apparatus for preserving the dynamic range of a relatively high dynamic range information stream, illustratively a high resolution video signal, subjected to a relatively low dynamic range encoding and/or transport process(es). The invention subjects the relatively high dynamic range information stream to a segmentation and remapping process whereby each segment is remapped to the relatively low dynamic range appropriate to the encoding and/or transport process(es) utilized. An auxiliary information stream includes segment and associated remapping information such that the initial, relatively high dynamic range information stream may be recovered in a post-encoding (i.e. decoding) or post-transport (i.e., receiving) process.

Claims

1. A method for encoding an information frame, comprising the steps of:

dividing said information frame into a plurality of information regions, at least one of said information regions comprising at least one information parameter having associated with it a plurality of intra-region values bounded by upper and lower value limits defining a dynamic range of said information parameter;

determining, for each of said at least one information region, a respective maximal value and a minimal value of said at least one information parameter;

remapping, for each of said at least one information regions and according to a single manipulation of the respective determined maximal and minimal values, said respective plurality of intra-region values of said at least one information parameter; and

encoding each information region.

2. The encoding method of claim 1, wherein said steps of encoding and determining produce, respectively, an encoded information stream and an associated dynamic range enhancement stream, said encoding method further comprising the step of:

transport encoding said encoded information stream and said associated dynamic range enhancement stream to form a transport stream for subsequent transmission.

3. The encoding method of claim 2, wherein said step of transport encoding comprises the step of:

including, in a private data section of said transport stream, said dynamic range enhancement stream.

4. The encoding method of claim 2, wherein said step of transport encoding comprises the step of:

associating said encoded information stream and said associated dynamic range enhancement stream with respective packet identification (PID) values.

5. The encoding method of claim 2, wherein said step of transport encoding comprises the steps of:

incorporating, into a packetized stream, said encoded information stream; and

including, within a header portion of said packetized stream, said associated dynamic range enhancement stream.

6. The encoding method of claim 2, further comprising the steps of:

transport decoding said transport stream to recover said encoded information stream and said associated dynamic range enhancement stream;

decoding said recovered encoded information stream to recover said information regions; and

inverse remapping, according to said respective maximal and minimal values, each of said at least one information parameters of said at least one information regions having associated with it a plurality of respective remapped intra-region values.

7. The encoding method of claim 1, wherein:

said information frame comprises an image frame and said at least one information parameter comprises at least one of a luminance parameter and a chrominance parameter; and

said steps of encoding and determining produce, respectively, an encoded image stream and an associated dynamic range enhancement stream.

8. The encoding method of claim 7, wherein said encoding step comprises compression encoding, using one of an JPEG-like compression encoder and an MPEG-like compression encoder, said information regions forming said information frame.

9. The encoding method of claim 8, further comprising the step of:

transport encoding said encoded information stream and said associated dynamic range enhancement stream to form a transport stream for subsequent transmission.

10. The encoding method of claim 9, further comprising the steps of:

transport decoding said transport stream to recover said encoded information stream and said associated dynamic range enhancement stream;

compression decoding said received encoded information stream to recover said remapped information regions; and

inverse remapping, according to said respective maximal and minimal values, each of said at least one information parameters of said at least one information regions having associated with it a plurality of respective remapped intra-region values.

11. The encoding method of claim 8, wherein each information region is defined with respect to one of a picture, frame, field, slice, macroblock, block, pixel location, and motion vector.

12. The encoding method of claim 7, wherein said step of remapping is performed in accordance with the following linear equation:

TP=└

OP*(TR/OR)+0.5┘

where;

TP=Target Pixel;

OP=Original Pixel;

TR=Target Range; and

OR=original Range.

13. The encoding method of claim 7, wherein said step of remapping is performed in accordance with a non-linear function comprising one of a gamma correction function and a companding function.

14. The encoding method of claim 1, wherein said step of remapping is performed in accordance one of a linear remapping function and a non-linear remapping function.

15. The encoding method of claim 1, wherein said steps of defining, determining, remapping and encoding are repeated for each of a plurality of information frames.

16. The encoding method of claim 15, wherein:

said plurality of information frames comprise image frames, said at least one information parameter comprises at least one of a luminance parameter and a chrominance parameter; and

said steps of encoding and determining produce, respectively, an encoded image stream and an associated dynamic range enhancement stream.

17. The encoding method of claim 15, wherein said encoding step comprises compression encoding, using an MPEG-like compression encoder, each information frame of said information stream.

18. The encoding method of claim 17, further comprising the step of transport encoding said encoded information stream and said associated dynamic range enhancement stream to form a transport stream for subsequent transmission.

19. The encoding method of claim 18, further comprising the steps of:

transport decoding said transport stream to recover said encoded information stream and said associated dynamic range enhancement stream;

compression decoding said received encoded information stream to recover said remapped information regions; and

inverse remapping, according to said respective maximal and minimal values, each of said at least one information parameters of said at least one information regions having associated with it a plurality of respective remapped intra-region values.

20. The encoding method of claim 16, wherein each information region is defined with respect to one of a picture, frame, field, slice, macroblock, block, pixel location, and motion vector.

21. The encoding method of claim 16, wherein said step of remapping is performed in accordance with the following linear equation:

TP=└

OP*(TR/OR)+0.5┘

where;

TP=Target Pixel;

OP=Original Pixel;

TR=Target Range; and

OR=original Range.

22. The encoding method of claim 16, wherein said step of remapping is performed in accordance with a non-linear function comprising one of a gamma correction function and a companding function.

23. A method for decoding an encoded information frame represented by a plurality of encoded information regions within an encoded information stream, where at least one of said plurality of encoded information regions comprises at least one information parameter having associated with it a plurality of remapped intra-region values, said method comprising the steps of:

decoding each of said plurality of encoded information regions to form a corresponding plurality of decoded information regions, said decoded information regions representing a decoded information frame;

extracting, from a dynamic range enhancement stream associated with said encoded information stream, respective maximal and minimal values for each of said at least one information parameter having associated with it a plurality of remapped intra-region values; and

inverse remapping, according to a single manipulation of said respective maximal and minimal values, each of said at least one information parameter of said at least one information regions having associated with it a respective plurality of remapped intra-region values.

24. The decoding method of claim 23, wherein said encoded information stream and said dynamic range enhancement stream associated with said encoded information stream comprises respective portions of a transport stream, said decoding method further comprising the step of:

demultiplexing said transport stream to recover said encoded information stream and said dynamic range enhancement stream.

25. The decoding method of claim 24, wherein said step of demultiplexing comprises the step of:

retrieving, from a private data section of said transport stream, said dynamic range enhancement stream.

26. The decoding method of claim 24, wherein said step of demultiplexing comprises the step of:

retrieving, according to respective packet identification (PID) values, said encoded information stream and said associated dynamic range enhancement stream.

27. The decoding method of claim 24, wherein said step of demultiplexing comprises the step of:

retrieving, from a packetized stream associated with a predefined packet identification (PID) value, said encoded information stream, said encoded information stream; and

retrieving, from a header portion of said packetized stream associated with a predefined packet identification (PID) value, said associated dynamic range enhancement stream.

28. The decoding method of claim 25, wherein said decoded information frame comprises an image frame and said at least one information parameter comprises at least one of a luminance parameter and a chrominance parameter.

29. The decoding method of claim 28, wherein said decoding step comprises compression decoding, using an MPEG-like compression decoder, said encoded information frame of said information stream.

30. The decoding method of claim 28, wherein said step of inverse remapping is performed in accordance with the following linear equation:

TP=└

OP*(TR/OR)+0.5┘

where;

TP=Target Pixel;

OP=Original Pixel;

TR=Target Range; and

OR=original Range.

31. The decoding method of claim 28, wherein said step of inverse remapping is performed in accordance with a non-linear function comprising one of a gamma correction function and a companding function.

32. The decoding method of claim 28, wherein each information region is defined with respect to one of a picture, frame, field, slice, macroblock, block, pixel location, and motion vector.

33. The decoding method of claim 23, wherein said steps of decoding, extracting and inverse remapping are repeated for each of a plurality of information frames within said encoded information stream and said dynamic range enhancement stream associated with said encoded information stream.

34. The decoding method of claim 33, wherein:

said plurality of information frames comprise image frames, said at least one information parameter comprises at least one of a luminance parameter and a chrominance parameter.

35. The decoding method of claim 34, wherein said decoding step comprises compression decoding, using an MPEG-like compression decoder, said encoded information frame of said information stream.

36. The decoding method of claim 34, wherein said step of inverse remapping is performed in accordance with the following linear equation:

TP=└

OP*(TR/OR)+0.5┘

where;

TP=Target Pixel;

OP=Original Pixel;

TR=Target Range; and

OR=original Range.

37. The decoding method of claim 34, wherein said step of inverse remapping is performed in accordance with a non-linear function comprising one of a gamma correction function and a companding function.

38. The decoding method of claim 34, wherein each information region is defined with respect to one of a picture, frame, field, slice, macroblock, block, pixel location, and motion vector.

39. In an information processing system including an information processor tending to reduce the dynamic range of a relatively high dynamic range information element within an information stream processed therein, a method for substantially preserving the dynamic range of said relatively high dynamic range information element comprising the steps of:

segmenting said information stream into a plurality of information regions;

determining the value of each occurrence of said relatively high dynamic range information element within each of said respective information regions;

generating indicia of a range of said determined values within each of said respective information regions;

remapping, in accordance with the respective generated statistical indicia and the dynamic range of said dynamic range reducing process, the value of each occurrence of said relatively high dynamic range information element within each of said respective information regions to produce a remapped information stream; and

processing, according to said dynamic range reducing process, said remapped information stream to produce a dynamic range reduced information stream comprising a plurality of information regions including respective dynamic range reduced information elements.

40. The method of claim 39, further comprising the step of:

inverse remapping, in accordance with respective generated indicia, the value of each occurrence of said dynamic range reduced information elements within each of said information regions of said dynamic range reduced information stream, to produce an dynamic range restored information stream.

41. Apparatus for processing an information stream comprising a plurality of information frames, said apparatus comprising:

a regional map and scale unit, coupled to receive said information stream, for segmenting a received information frame into one or more information regions, and for remapping one or more relatively high dynamic range information parameters associated with each information region according to respective intra-region information parameter maxima and minima to produce a remapped information stream and an associated map region identification stream, said one or more remapped information parameters having a relatively low dynamic range; and

a compression encoder, coupled to said regional map and scale unit, for compression encoding said remapped information stream to produce a compression encoded information stream, wherein said regional map and scale unit imparts a transfer characteristic to said remapped information stream comprising at least one of a gamma correction characteristic, a companding characteristic, a redistribution characteristic, a linear characteristic, an arbitrary polynomial characteristic and a pre-determined function characteristic.

42. Apparatus for processing an information stream comprising a plurality of information frames, said apparatus comprising:

a regional map and scale unit, coupled to receive said information stream, for segmenting a received information frame into one or more information regions, and for remapping one or more relatively high dynamic range information parameters associated with each information region according to respective intra-region information parameter maxima and minima to produce a remapped information stream and an associated map region identification stream, said one or more remapped information parameters having a relatively low dynamic range; and

an compression encoder, coupled to said regional map and scale unit, for compression encoding said remapped information stream to produce a compression encoded information stream, wherein each information region is defined with respect to one of a picture, frame, field, slice, macroblock, block, pixel location, and motion vector.

43. An apparatus for decoding an encoded information frame represented by a plurality of encoded information regions within an encoded information stream, where at least one of said plurality of encoded information regions comprises at least one information parameter having associated with it a plurality of remapped intra-region values, said apparatus comprising:

a decoder, for decoding each of said plurality of encoded information regions to form a corresponding plurality of decoded information regions, said decoded information regions representing a decoded information frame; and

an inverse map and scale unit, for extracting, from a dynamic range enhancement stream associated with said encoded information stream, respective maximal and minimal values for each of said at least one information parameter having associated with it a plurality of remapped intra-region values;

said and inverse map and scale unit inverse remapping, according to a single manipulation of said respective maximal and minimal values, each of said at least one information parameter of said at least one information regions having associated with it a respective plurality of remapped intra-region values.

44. The apparatus of claim 43, wherein said encoded information stream and said dynamic range enhancement stream associated with said encoded information stream comprises respective portions of a transport stream, said apparatus further comprising:

a transport decoder and demultiplexer, for processing said transport stream to recover said encoded information stream and said dynamic range enhancement stream.

45. The apparatus of claim 44, wherein said transport decoder and demultiplexer retrieves, from a private data section of said transport stream, said dynamic range enhancement stream.

46. The apparatus of claim 44, wherein said transport decoder and demultiplexer retrieves, according to respective packet identification (PID) values, said encoded information stream and said associated dynamic range enhancement stream.

47. The apparatus of claim 44, wherein:

said transport decoder and demultiplexer retrieves, from a packetized stream associated with a predefined packet identification (PID) value, said encoded information stream, said encoded information stream; and

said transport decoder and demultiplexer retrieves, from a header portion of said packetized stream associated with a predefined packet identification (PID) value, said associated dynamic range enhancement stream.

48. The apparatus of claim 43, wherein:

said decoded information frame comprises an image frame and said at least one information parameter comprises at least one of a luminance parameter and a chrominance parameter; and

said compression decoder comprises an MPEG-like compression decoder.

49. The apparatus of claim 48, wherein:

said inverse map and scale unit performs said inverse remapping function in accordance with the following linear equation;

TP=└

OP*(TR/OR)+0.5┘

where;

TP=Target Pixel;

OP=Original Pixel;

TR=Target Range; and

OR=original Range.

50. The apparatus of claim 48, wherein:

said inverse map and scale unit performs said inverse remapping function in accordance with a non-linear function comprising one of a gamma correction function and a companding function.

51. The apparatus of claim 48, wherein each information region is defined with respect to one of a picture, frame, field, slice, macroblock, block, pixel location, and motion vector.

52. The apparatus of claim 43, wherein:

said encoded information stream and said dynamic range enhancement stream associated with said encoded information stream represent a plurality of encoded information frames; and

said apparatus processes each of said plurality of encoded information frames to produce a corresponding plurality of decoded information frames.

53. The apparatus of claim 52, wherein said plurality of decoded information frames comprise image frames and said at least one information parameter comprises at least one of a luminance parameter and a chrominance parameter;

and

said compression decoder comprises an MPEG-like compression decoder.

54. The apparatus of claim 53, wherein:

said inverse map and scale unit performs said inverse remapping function in accordance with the following linear equation;

TP=└

OP*(TR/OR)+0.5┘

where;

TP=Target Pixel;

OP=Original Pixel;

TR=Target Range; and

OR=original Range.

55. The apparatus of claim 53, wherein:

said inverse map and scale unit performs said inverse remapping function in accordance with a non-linear function comprising one of a gamma correction function and a companding function.

56. The apparatus of claim 53, wherein each information region is defined with respect to one of a picture, frame, field, slice, macroblock, block, pixel location, and motion vector.