Content-adaptive compression encoding

• US 6,477,201 B1
• Filed: 05/22/1998
• Issued: 11/05/2002
• Est. Priority Date: 05/22/1998
• Status: Expired due to Term

• Current Assignee: MediaTek, Inc.
• Original Assignee: Sarnoff Corporation (SRI International, Inc.)
• Inventors: Reitmeier, Glenn Arthur, Tinker, Michael, Stiller, Thomas Michael, Wine, Charles Martin
• Primary Examiner(s): BRITTON, HOWARD W
• Application Number:
  US09/083,451
• Time in Patent Office: 1,628 Days
• Field of Search: 375/240, 375/240.08, 382/243
• US Class Current: 375/240.08
• CPC Class Codes: H04N 19/117 Filters, e.g. for pre-processing or post-processing sub-band filter banks H04N19/635
• CPC Class Codes: H04N 19/124 Quantisation
• CPC Class Codes: H04N 19/14 Coding unit complexity, e.g. amount of activity or edge presence estimation H04N19/146 takes precedence
• CPC Class Codes: H04N 19/154 Measured or subjectively estimated visual quality after decoding, e.g. measurement of distortion use of rate-distortion criteria H04N19/147
• CPC Class Codes: H04N 19/17 the unit being an image region, e.g. an object
• CPC Class Codes: H04N 19/172 the region being a picture, frame or field
• CPC Class Codes: H04N 19/20 using video object coding
• CPC Class Codes: H04N 19/537 Motion estimation other than block-based
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 19/80 Details of filtering operations specially adapted for video compression, e.g. for pixel interpolation H04N19/635, H04N19/86 take precedence
• CPC Class Codes: H04N 19/85 using pre-processing or post-processing specially adapted for video compression

Abstract

A subjective evaluator delineates regions of an information space to be encoded in a qualitatively preferential or non-preferential manner such that the encoded information space comprises one or more of normal, emphasized or de-emphasized information content.

Claims

1. A method for selectively encoding an information stream, said Information stream comprising a plurality of information frames, said method comprising the steps of:

(a) generating, in response to a subjective evaluation of the contents of an information frame, a mask indicative of a desired encoding quality adjustment for one or more information regions within said information frame;

(b) associating each of said one or more information regions with respective encoding quality adjustment indicia; and

(c) encoding said information frame in accordance with said encoding quality adjustment indicia.

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

(d) adapting said mask to a subsequent information frame.

3. The method of claim 2, wherein said step of adapting comprises the steps of:

comparing said information frame and said subsequent information frame to produce difference information;

extracting, from said difference information, inter-frame motion indicia of information sub-regions within each of said information regions; and

warping, according to said extracted inter-frame motion indicia, said mask.

4. The method of claim 1, wherein:

said information stream comprises a video information stream; and

said mask comprises a graphical overlay.

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

calculating an inter-frame flow descriptor relating an information frame mask geometry to a subsequent information frame mask geometry; and

warping, according to said calculated inter-frame flow descriptor, said mask.

6. The method of claim 5, wherein said inter-frame flow descriptor comprises an optical flow descriptor.

7. The method of claim 5, wherein said inter-frame flow descriptor comprises a motion vector descriptor.

8. The method of claim 5, wherein said inter-frame flow descriptor comprises a frequency band flow descriptor.

9. The method of claim 1, wherein said mask utilizes color to delineate information regions having a different desired encoding quality.

10. The method of claim 9, wherein a first color is indicative of an information region to be qualitatively enhanced, and a second is indicative of an information region to be qualitatively degraded.

11. The method of claim 10, wherein qualitative information enhancement is provided by preferential bit allocation during an encoding step.

12. The method of claim 10, wherein qualitative information degradation is provided by at least one of information sub-sampling prior to an encoding step and non-preferential bit allocation during said encoding step.

13. The method of claim 1, wherein said desired encoding quality is attained using at least one of a bit allocation, regional filtering and sub-regional filtering method.

14. A computer readable media storing a computer program which, when executed by a computer, implements a method for selectively encoding an information stream, said information stream comprising a plurality of information frames, said method comprising the steps of:

(a) generating, in response to a subjective evaluation of the contents of an information frame, a mask indicative of a desired encoding quality adjustment for one or more information regions within said information frame;

(b) associating each of said one or more information regions with respective encoding quality adjustment indicia; and

(c) encoding said information frame in accordance with said encoding quality adjustment indicia.

15. The computer readable media of claim 14, wherein the method implemented by said stored computer program comprises the step of:

(d) adapting said mask to a subsequent information frame.

16. The computer readable media of claim 15, wherein said step of adapting comprises the steps of:

comparing said information frame and said subsequent information frame to produce difference information;

extracting, from said difference information, inter-frame motion indicia of information sub-regions within each of said information regions; and

warping, according to said extracted inter-frame motion indicia, said mask.

17. An apparatus for selectively encoding an information stream comprising a plurality of information frames, said apparatus comprising:

a subjective evaluator, coupled to receive said information stream, for subjectively evaluating at least one information frame and generating therefrom a signal indicative of a region of said information frame to be encoded according to a non-standard encoding preference;

a mask generator, coupled to receive said information stream and coupled to said subjective evaluator, for generating a mask delineating said region of said information frame to be encoded according to a non-standard encoding preference; and

an encoder, coupled to receive said information stream and coupled to said mask generator, for encoding said information stream, wherein said region of said information frame to be encoded according to a non-standard encoding preference is encoded according to said non-standard encoding preference.

18. The apparatus of claim 17, wherein said non-standard encoding preference comprises one of a qualitative encoding enhancement or qualitative encoding degradation preference.

19. The apparatus of claim 17, further comprising:

a region association and flow calculator, coupled to receive said information stream and coupled to said mask generator, for associating information elements within said region of said information frame delineated by said mask with information elements of a successive information frame, and producing an output signal indicative of an inter-frame information flow.

20. The apparatus of claim 19, wherein:

said mask generator is coupled to said region association and flow calculator, and is responsive to said indicia of inter-frame information flow to warp said mask to conform to said inter-frame information flow.