Systems and methods to determine a contrast and a brightness adjusted system tone reproduction curve

• US 6,753,987 B1
• Filed: 02/25/2000
• Issued: 06/22/2004
• Est. Priority Date: 02/25/2000
• Status: Expired due to Term

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Tse, Francis, Fisher, Julie A., Loverde, Regina M., Farnung, Charles E., Nagarajan, Ramesh, Huedepohl, Ralph H.
• Primary Examiner(s): Wallerson, Mark
• Assistant Examiner(s): Lett, Thomas J.
• Application Number:
  US09/512,888
• Time in Patent Office: 1,579 Days
• Field of Search: 345/600, 345/150, 345/153, 345/147, 345/154, 345/589, 345/603, 348/179, 348/655, 358/504, 358/518, 358/448, 358/520, 358/519, 358/1.9, 358/515, 358/517, 358/537, 358/452, 382/167
• US Class Current: 358/518
• CPC Class Codes: H04N 1/407 Control or modification of tonal gradation or of extreme levels, e.g. background level

Abstract

Contrast and brightness adjustments can be made to a system tone reproduction curve. These contrast and brightness adjustments can be made, for example, by user, via a user input device, or alternatively, automatically detected, based on an image analysis routine. By determining one or more generic tone reproduction curves, and interpolating these tone reproduction curves with the system tone reproduction curve, a new, adjusted tone reproduction curve is produced. This allows for a determination of the adjusted system tone reproduction curve as opposed to calculating and restoring the families of system tone reproduction curves adjusted for all the possible combinations of contrast and brightness.

Claims

1. A system that determines a contrast and a brightness adjusted tone reproduction curve comprising:

an input device that receives at least one of contrast and brightness information;

at least one tone reproduction curve determination device that determines at least one of a contrast tone reproduction curve and a brightness tone reproduction curve; and

a tone reproduction curve adjusting device that adjusts a tone reproduction curve based on the at least one determined contrast and brightness tone reproduction curves and determines an image processing tone reproduction curve.

2. The system of claim 1, further comprising a coordinate determination device that aligns the adjusted tone reproduction curve and a system tone reproduction curve.

3. The system of claim 1, further comprising a cascading device that cascades the adjusted tone reproduction curve with a system tone reproduction curve.

4. The system of claim 1, further comprising a tone reproduction curve smoothing device that smoothes the adjusted tone reproduction curve.

5. The system of claim 1, further comprising an image processing device that determines an image processing tone reproduction curve based on the adjusted tone reproduction curve and an output tone reproduction curve.

6. The system of claim 5, wherein the image processing device manipulates an image based on the image processing tone reproduction curve.

7. A method for determining a contrast and a brightness adjusted tone reproduction curve comprising:

receiving at least one of contrast and brightness information;

determining at least one of a contrast tone reproduction curve and a brightness tone reproduction curve; and

adjusting a tone reproduction curve based on the at least one determined contrast and brightness tone reproduction curves and determining an image processing tone reproduction curve.

8. The method of claim 7, further comprising aligning the adjusted tone reproduction curve and a system tone reproduction curve.

9. The method of claim 7, further comprising cascading the adjusted tone reproduction curve with a system tone reproduction curve.

10. The method of claim 7, further comprising smoothing the adjusted tone reproduction curve.

11. The method of claim 7, further comprising determining an image processing tone reproduction curve based on the adjusted tone reproduction curve and an output tone reproduction curve.

12. The method of claim 11, wherein the image processing device manipulates an image based on the image processing tone reproduction curve.

13. An information storage medium comprising information that determines a contrast and a brightness adjusted tone reproduction curve comprising:

information that receives at least one of contrast and brightness information;

information that determines at least one of a contrast tone reproduction curve and a brightness tone reproduction curve; and

information that adjusts a tone reproduction curve based on the at least one determined contrast and brightness tone reproduction curves and determines an image processing tone reproduction curve.