Granted Patent B2

US 7,053,960 · App. 10/266,827 · Granted May 30, 2006

Abstract

Claims (56)

1. A method for adjusting image contrast comprising:

receiving a television signal;

determining a format of the television signal;

outputting in conjunction with the television signal a reference level that is substantially equal to a luminance level representing a black color in a first format responsive to the determining that the television signal has the first format; and

outputting in conjunction with the television signal a reference level that is substantially equal to a luminance level representing a black color in a second format responsive to the determining that the television signal has the second format.

2. The method of claim 1 , wherein the reference level is a reference black level.

3. The method of claim 1 , wherein the reference level is a blanking level.

4. The method of claim 1 , wherein the first format is a standard definition format and the second format is a high definition format.

5. The method of claim 1 , wherein the first format is an NTSC format and the second format is a high definition format.

6. The method of claim 1 , further comprising:

responsive to the determining that the television signal has the first format, amplifying the television signal in order to cause a difference in luminance levels between a luminance level of a signal portion representing a white color and a luminance level of a signal portion representing a black color to be substantially equal to a difference in luminance levels between a black color level and a white color level in the second format.

7. The method of claim 1 , wherein the luminance level representing a black color in the first format is 16 on a scale of 16 to 235.

8. The method of claim 1 , wherein the level representing a black color in the second format is 0 on a scale of 0 to 255.

9. A system for adjusting image contrast comprising:

a processor; and

memory containing software that is configured to be executed by the processor and that is programmed to cause the processor to:

determine a format for a television signal;

cause a reference level that is substantially equal to a luminance level representing a black color in a first format to be output in conjunction with the television signal responsive to the determining that the television signal has the first format; and

cause a reference level that is substantially equal to a luminance level representing a black color in a second format to be output in conjunction with the television signal responsive to the determining that the television signal has the second format.

10. The system of claim 9 , wherein the reference level is a reference black level.

11. The system of claim 9 , wherein the reference level is a blanking level.

12. The system of claim 9 , wherein the first format is a standard definition format and the second format is a high definition format.

13. The system of claim 9 , wherein the first format is an NTSC format and the second format is a high definition format.

14. The system of claim 9 , wherein the software is further programmed to cause the processor to:

responsive to the determining that the television signal has the first format, cause the television signal to be modified such that a difference in luminance levels between a signal portion representing a white color and a signal portion representing a black color is substantially equal to a difference in luminance levels between a black color level and a white color level in the second format.

15. The system of claim 9 , wherein the level representing a black color in the first format is 16 on a scale of 16 to 235.

16. The system of claim 9 , wherein the level representing a black color in the second format is 0 on a scale of 0 to 255.

17. A method for adjusting image contrast comprising:

determining a format of a television signal;

responsive to the determining that the television signal has a first format, adding a voltage offset to the television signal in order to substantially align portions of the television signal representing a black color with a reference level.

18. The method of claim 17 , wherein the reference level is a reference black level.

19. The method of claim 17 , wherein the reference level is a blanking level.

20. The method of claim 17 , wherein the first format is an NTSC format.

21. The method of claim 17 , further comprising:

responsive to the determining that the television signal has the first format, amplifying the television signal in order to cause a difference in luminance levels between a signal portion representing a white color and a signal portion representing a black color to be substantially equal to a difference in luminance levels between a black color level and a white color level in a second format.

22. The method of claim 17 , wherein the level representing a black color in the first format is 16 on a scale of 16 to 235.

23. A system for adjusting image contrast comprising:

a processor; and

memory containing software that is configured to be executed by the processor and that is programmed to cause the processor to:

determine a format for a television signal; and

responsive to the determining that the television signal has a first format, add a voltage offset to the television signal in order to substantially align portions of the television signal representing a black color with a reference level.

24. The system of claim 23 , wherein the reference level is a reference black level.

25. The system of claim 23 , wherein the reference level is a blanking level.

26. The system of claim 23 , wherein the first format is an NTSC format.

27. The system of claim 23 , wherein the software is further programmed to cause the processor to:

responsive to the determining that the television signal has the first format, cause the television signal to be modified such that a difference in luminance levels between a signal portion representing a white color and a signal portion representing a black color is substantially equal to a difference in luminance levels between a black color level and a white color level in a second format.

28. The system of claim 23 , wherein the level representing a black color in the first format is 16 on a scale of 16 to 235.

29. A method for adjusting image contrast comprising:

determining a format of a television signal;

outputting in conjunction with the television signal a reference level that is substantially equal to a luminance level representing a black color in a first format responsive to the determining that the television signal has the first format;

outputting in conjunction with the television signal a reference level that is substantially equal to a luminance level representing a black color in a second fonnat responsive to the determining that the television signal has the second format; and

responsive to the determining that the television signal has the first format, amplifying the television signal in order to cause a difference in luminance levels between a signal portion representing a white color and a signal portion representing a black color to be substantially equal to a difference in luminance levels between a black color level and a white color level in the second format;

wherein the reference level is a reference black level;

wherein the first format is an NTSC format and the second format is a high definition format;

wherein the level representing a black color in the first format is 16 on a scale of 16 to 235; and

wherein the level representing a black color in the second format is 0 on a scale of 0 to 255.

Assignments (11)