Methods and systems for enhancing display characteristics with ambient illumination input

• US 7,839,406 B2
• Filed: 03/08/2006
• Issued: 11/23/2010
• Est. Priority Date: 03/08/2006
• Status: Expired due to Fees

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Laboratories of America Incorporated (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Kerofsky, Louis Joseph
• Primary Examiner(s): Amini; Javid A
• Application Number:
  US11/371,466
• Publication Number:
  US 20070211049A1
• Time in Patent Office: 1,721 Days
• Field of Search: 345/426, 345/473
• US Class Current: 345/473
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2320/0653 Controlling or limiting the speed of brightness adjustment of the illumination source
• CPC Class Codes: G09G 2320/066 for control of contrast
• CPC Class Codes: G09G 2320/0673 for control of gamma adjustment, e.g. selecting another gamma curve
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 3/28 using luminous gas-discharge panels, e.g. plasma panels
• CPC Class Codes: G09G 3/32 semiconductive, e.g. using light-emitting diodes [LED]
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336

Abstract

Embodiments of the present invention comprise systems, methods and devices for adjusting image code values for enhanced image display.

Claims

1. A method for adjusting image characteristics, said method comprising:

a. receiving an input image;

b. receiving ambient illumination data;

c. determining a reduced source light illumination level for an image display device source light, said reduced source light illumination level being based on said ambient illumination data, wherein said reduced source light illumination level is less than a full brightness level;

d. calculating a tone scale adjustment model based on said reduced source light illumination level;

wherein said tone scale adjustment model fully compensates said input image for said reduced source light illumination level only for input image code values below a maximum fidelity point and partially compensates for said reduced source light illumination level with a roll-off curve only for input image code values above said maximum fidelity point and wherein said calculating is performed by a processor and a memory; and

e. applying said tone scale adjustment model to said input image.

2. A method as described in claim 1 wherein said tone scale adjustment model is also based on said input image.

3. A method for adjusting image characteristics, said method comprising:

a. receiving an input image;

b. receiving ambient illumination data;

c. determining a reduced source light illumination level for an image display device source light, said reduced source light illumination level being based on said ambient illumination data, wherein said reduced source light illumination level is less than a full-brightness level;

d. said tone scale adjustment model comprises filtering said input image to create a high-pass image and a low-pass image;

e. applying a first constant positive gain multiplier greater than one only to all code values in said high pass image;

f. applying a second constant gain multiplier greater than one only to all code values in said low-pass image that have values lower than a maximum fidelity point (MFP), wherein said second constant gain multiplier compensates said low-pass image code values for said reduced source light illumination level, wherein said applying a second constant gain multiplier is performed by a processor and a memory; and

g. applying a roll-off curve only to all code values in said low-pass image that have values greater than said MFP.

4. A system for adjusting image characteristics, said system comprising:

a. an image receiver for receiving an input image;

b. an ambient data receiver for receiving ambient illumination data;

c. a source light processor for determining a reduced source light illumination level for an image display device source light, said reduced source light illumination level being based on said ambient illumination data, wherein said reduced source light illumination level is less than a full brightness illumination level;

d. a tone scale generator for calculating a tone scale adjustment model based on said reduced source light illumination level, wherein said tone scale adjustment model fully compensates code values in said input image that are below a maximum fidelity point for said reduced source light illumination level and said tone scale adjustment model only partially compensates code values in said input image that are above said maximum fidelity point for said reduced source light illumination level using a roll-off curve; and

e. a first image processor for applying said tone scale adjustment model to said input image.

5. A system as described in claim 4 further comprising a filter for filtering said input image, thereby creating a high-pass image and a low-pass image;

a second image processor for applying a constant positive gain multiplier greater than one to said high pass image; and

wherein said applying said tone scale adjustment model comprises applying said tone scale adjustment model only to said low-pass image.

6. A system as described in claim 4 wherein said tone scale adjustment model is also based on said input image.