Method and apparatus for adjusting the quality of digital media

• US 6,760,442 B1
• Filed: 12/18/1998
• Issued: 07/06/2004
• Est. Priority Date: 12/18/1998
• Status: Expired due to Term

• Current Assignee: Oracle America, Inc. (Oracle Corporation)
• Original Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: Scott, Glenn C.
• Primary Examiner(s): Meislahn, Douglas J.
• Application Number:
  US09/216,280
• Time in Patent Office: 2,027 Days
• Field of Search: 380/268, 380/201
• US Class Current: 380/268
• CPC Class Codes: H04N 21/23476 by partially encrypting, e.g. encrypting the ending portion of a movie
• CPC Class Codes: H04N 21/44055 by partially decrypting, e.g. decrypting a video stream that has been partially encrypted
• CPC Class Codes: H04N 7/1675 Providing digital key or authorisation information for generation or regeneration of the scrambling sequence pseudo-random number generators in general G06F7/58

Abstract

A method and system are disclosed for adjusting the resolution or performance of digital media in a reversible manner. A mask component having a length of a predetermined number of bits is extracted from a high-resolution ordinal component of digital data having an initial state. Another non-ordered, randomly generated second component having the same predetermined number of bits is received. A logic operation using the mask component and the second, non-ordered component is performed thereby deriving a third component also having the same predetermined number of bits. The high-resolution ordinal component of digital data is altered using the derived third component, thereby adjusting the initial state of the high-resolution ordinal component to a secondary state that can be reverted to its initial state by virtue of the logic operation being reversible given the correct, corresponding operands.

Claims

1. A method of adjusting resolution of digital data having a first resolution, the method comprising:

extracting a first portion having a length of a first predetermined number of least significant bits from a first component of the digital data, the first component having a primary state, the predetermined number being based upon a desired level of resolution adjustment of the digital data;

receiving a second component of non-ordered digital data having a length of the first predetermined number of least significant bits;

performing a first logic operation using the first portion and the second component thereby deriving a third component having a length of the first predetermined number of least significant bits; and

altering the first component of the digital data using the third component whereby the primary state of the first component is adjusted to a secondary state and as a result of the altering the resolution of digital data is adjusted to a second resolution that is different from the first resolution.

2. The method of claim 1, further comprising re-altering the first component by performing a second logic operation on all or fewer than the first predetermined number of bits in the third component and a fourth component of non-ordered data having a length equal to or less than the first predetermined number of bits, whereby the secondary state of the first component is adjusted to be closer to the primary state and as a result of the re-altering the resolution of data is re-adjusted from the second resolution to be closer to the first resolution.

3. A method as recited in claim 1 wherein the first component of digital data is part of a transient data stream.

4. A method as recited in claim 3 wherein the transient data stream contains ordered data.

5. A method as recited in claim 1 further comprising generating the second component of non-ordered digital data from a first pseudo random number generator.

6. A method as recited in claim 5 further comprising using a first seed value in the first pseudo-random number generator to generate a first sequence of pseudo-random numbers from which the second component of non-ordered digital data is extracted.

7. A method as recited in claim 1 wherein performing a first logic operation further comprises performing an exclusive OR operation between the bits in the first portion and the bits in the second component.

8. A method as recited in claim 2, wherein performing a second logic operation further comprises performing an exclusive OR operation between the bits in the third component and the bits in the fourth component of non-ordered data.

9. A method as recited in claim 8 further comprising generating the fourth component of non-ordered data from a second pseudo-random number generator.

10. A method as recited in claim 9, further comprising using a second seed in the second pseudo-random number generator to generate a second sequence of pseudo-random numbers from which the fourth component is extracted.

11. A method as recited in claim 8 wherein performing an exclusive OR operation further comprises using fewer than the first predetermined number of least significant bits in the third component and fewer than the first predetermined number of bits in the fourth component of non-ordered data.

12. A method as recited in claim 1 wherein altering the first component of the digital data further comprises replacing the first portion with the third component.

13. A method as recited in claim 12 wherein the bits in the first portion of the first component, the first component having a plurality of bits, are the least significant bits of the plurality of bits of the first component.

14. A system for adjusting resolution of digital data having a first resolution, the system comprising:

a bit segment extractor for extracting a first portion from a first component of the digital data wherein the first portion has a length of a first predetermined number of least significant bits and the first component has a primary state, the predetermined number being based upon a desired level of resolution adjustment of the digital data;

a data generator for creating a second component of non-ordered digital data having a length of the first predetermined number of least significant bits;

an arithmetic logic unit for performing a first logic operation using the first portion and the second component wherein a third component is derived having a length of the first predetermined number of least significant bits; and

a data component manipulator for altering the first component of the digital data using the third component wherein the primary state of the first component is adjusted to a secondary state, thereby adjusting the resolution of digital data from the first resolution to a second resolution that is different than the first resolution.

15. A system as recited in claim 14 wherein the arithmetic logic unit performs an exclusive OR operation between the bits in the first portion and the bits in the second component.

16. A system as recited in claim 14 further comprising:

a receiving arithmetic logic unit for performing a second logic operation on all or fewer than the first predetermined number of least significant bits in the third component and a fourth component of non-ordered data having a length equal to or less than the first predetermined number of least significant bits; and

a receiving data component manipulator for re-altering the first component wherein the secondary state of the first component is adjusted to be closer to the primary state.

17. A system as recited in claim 16 wherein the receiving arithmetic logic unit performs an exclusive OR operation between the bits in the third component and the bits in the fourth component of non-ordered data.

18. A system as recited in claim 17 further comprising:

a second pseudo-random number generator for generating the fourth component of non-ordered data.

19. A system as recited in claim 14 wherein the data component manipulator for altering the first component of the digital data replaces the first portion with the third component.

20. A system as recited in claim 14 further comprising:

a first pseudo-random number generator for generating the second component of non-ordered digital data.

21. A system for adjusting the quality of digital media having a plurality of bits;

the system comprising;

a random number generator for generating a random number; and

a data bit manipulator for altering an original portion of the plurality of bits in the digital media using the random number, the original portion comprising a predetermined number of least significant bits, the predetermined number being based upon a desired level of quality adjustment of the digital media, wherein an exclusive OR operator using as operands the random number and the original portion of the plurality of bits derives an altered segment, and wherein the original portion of the plurality of bits is replaced with the altered segment thereby adjusting the quality of the digital media.

22. A system as recited in claim 21 further comprising:

a receiving data bit manipulator for altering the altered segment of the plurality of bits in the digital media using the random number, wherein a secondary exclusive OR operator using as operands the random number and the altered segment derives the original portion of the plurality of bits, and wherein the altered segment is replaced with the original portion of the plurality of bits thereby readjusting the quality of the digital media.

23. A system as recited in claim 22 wherein the secondary exclusive OR operator accepts as operands a random number segment having a specific number of bits of the random number and a subsegment of the altered segment, the subsegment having the specific number of bits.

24. A computer readable medium containing programmed instructions arranged to adjust resolution of digital data having a first resolution, the computer readable medium including programmed instructions for:

extracting a first portion having a length of a first predetermined number of least significant bits from a first component of the digital data, the first component having a primary state, the predetermined number being based upon a desired level of resolution adjustment of the digital data;

receiving a second component of non-ordered digital data having a length of the first predetermined number of least significant bits;

performing a first logic operation using the first portion and the second component thereby deriving a third component having a length of the first predetermined number of least significant bits; and

altering the first component of the digital data using the third component whereby the primary state of the first component is adjusted to a secondary state and as a result of the altering the resolution of digital data is adjusted from the first resolution to a second resolution that is different than the first resolution.

25. A computer readable medium as recited in claim 24 further comprising programmed instructions for:

re-altering the first component by performing a second logic operation on all or fewer than the first predetermined number of least significant bits in the third component and a fourth component of non-ordered data having a length equal to or less than the first predetermined number of least significant bits whereby the secondary state of the first component is adjusted to be closer to the primary state.

26. A computer readable medium as recited in claim 25 wherein the programmed instructions for performing a second logic operation further comprises programmed instructions for performing an exclusive OR operation between the bits in the third component and the bits in the fourth component of non-ordered data.

27. A computer readable medium as recited in claim 26 further comprising programmed instructions for generating the fourth component of non-ordered data from a second pseudo-random number generator.

28. A computer readable medium as recited in claim 26 wherein the programmed instructions for performing an exclusive OR operation further comprises programmed instructions for using fewer than the first predetermined number of least significant bits in the third component and fewer than the first predetermined number of least significant bits in the fourth component of non-ordered data.

29. A computer readable medium as recited in claim 24 wherein the programmed instructions for altering the first component of the digital data further comprises programmed instructions for replacing the first portion with the third component.

30. A computer readable medium as recited in claim 24 further comprising programmed instructions for generating the second component of non-ordered digital data from a first pseudo-random number generator.

31. A computer readable medium as recited in claim 24 further comprising programmed instructions for using a first seed value with the first pseudo-random number generator to generate a first sequence of pseudo-random numbers from which the second component of non-ordered digital data is extracted.

32. A computer readable medium as recited in claim 24 wherein the programmed instructions for performing a first logic operation further comprises programmed instructions for performing an exclusive OR operation between the bits in the first portion and the bits in the second component.

33. A computer data signal embodied in a carrier wave and representing sequences of instructions arranged to adjust resolution of digital data having a first resolution, the sequence of instructions comprising:

extracting a first portion having a length of a first predetermined number of least significant bits from a first component of the digital data, the first component having a primary state, the predetermined number being based upon a desired level of resolution adjustment of the digital data;

receiving a second component of non-ordered digital data having a length of the first predetermined number of least significant bits;

performing a first logic operation using the first portion and the second component thereby deriving a third component having a length of the first predetermined number of least significant bits; and

altering the first component of the digital data using the third component whereby the primary state of the first component is adjusted to a secondary state and as a result the resolution of digital data is adjusted from a first resolution to a second resolution.

34. A computer data signal embodied in a carrier wave as recited in claim 33 further comprising sequences of instructions for:

re-altering the first component by performing a second logic operation on all or fewer than the first predetermined number of bits in the third component and a fourth component of non-ordered data having a length equal to or less than the first predetermined number of bits whereby the secondary state of the first component is adjusted to be closer to the primary state.