VIDEO SIGNAL PROCESSING DEVICE, VIDEO SIGNAL PROCESSING METHOD, VIDEO SIGNAL PROCESSING PROGRAM, INTEGRATED CIRCUIT, AND VIDEO SIGNAL DISPLAY DEVICE

• US 20080174605A1
• Filed: 01/22/2008
• Published: 07/24/2008
• Est. Priority Date: 01/23/2007
• Status: Active Grant

• Current Assignee: Sovereign Peak Ventures, LLC (Dominion Harbor Enterprises, LLC)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Toji, Bumpei, Kiuchi, Shinya, Hirashima, Tsuyoshi
• Granted Patent: US 8,049,764 B2
• Time in Patent Office: Days
• US Class Current: 345/531
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/22 using controlled light sources
• CPC Class Codes: G09G 5/10 Intensity circuits
• CPC Class Codes: H04N 5/20 Circuitry for controlling amplitude response

Abstract

On the display screen of a video signal display device, when the emission amount is monotonically lowered toward the screen periphery from a certain point (screen center), if there are a plurality of regions that viewers notice easily (such as faces), then correction by monotically decreasing the emission amount cannot always raise the signal level in the regions that are noticed, and it may not be possible to obtain a sufficient sense of brightness. In the video signal processing device, a multiple object detection portion detects a plurality of objects that are included in a unit image, and a correction gain is calculated such that when the unit image is displayed on the display device, a point on the display screen at which an emission amount that is lower than the emission amount on the display screen at a point that is substantially in the center between any two objects is in a region between the points substantially in the center of the two objects, and the input video signal is corrected with that correction gain. Thus, it is possible to maintain a sense of brightness about a plurality of objects on the display screen that are readily noticed by viewers, while suppressing power usage by the display device that displays the video signal.

Claims

1. A video signal processing device for creating a display video signal to be displayed on a light-adjustable display device, comprising:

a multiple object detection portion operable to detect a plurality of objects that are included in a unit image that is formed by an input video signal;

a correction gain calculation portion operable to calculate a correction gain such that when the unit image is displayed on the display device, a point on a display screen at which an emission amount that is lower than the emission amount on the display screen at a point that is substantially in the center between any two objects is in a region between the points substantially in the center of the two objects; and

a signal level correction portion operable to correct the input video signal in accordance with the correction gain and output the result to the display device as the display video signal.

2. The video signal processing device according to claim 1,

wherein the correction gain calculation portion includes a same number of slope gain creation portions, which are operable to calculate a slope gain for each object that has been calculated by the multiple object detection portion, as a maximum number of detectable objects, and a slope gain joining portion operable to join the slope gain of each object to create a single correction gain.

3. The video signal processing device according to claim 2,

wherein the slope gain creation portions are corresponded with the order of detection of the objects that are detected by the multiple object detection portion.

4. The video signal processing device according to claim 2,

wherein the slope gain creation portions are corresponded in order with the size of the objects that are detected by the multiple object detection portion.

5. The video signal processing device according to claim 2,

wherein the maximum number of detectable objects is a number that is set in advance.

6. The video signal processing device according to claim 2,

wherein the slope gain joining portion takes the smallest slope gain of each object as the correction gain;

and

wherein the signal level correction portion corrects the input video signal by a factor of (1−

(the correction gain)).

7. The video signal processing device according to claim 2,

wherein each slope gain creation portion has a distance calculation portion operable to calculate, for each pixel making up the unit image, a distance between the object and the pixel, and a gain calculation portion operable to calculate the slope gain in accordance with the distance that has been calculated by the distance calculate portion.

8. The video signal processing device according to claim 7,

wherein the gain calculation portions calculate the slope gain such that the slope gain increases the greater the distance from the substantial center point of the object.

9. The video signal processing device according to claim 8,

wherein the gain calculation portions calculate the slope gain through a Gaussian function.

10. The video signal processing device according to claim 2,

wherein each slope gain creation portion further comprises an object distance calculation portion that is corresponded to the object that has been detected by the multiple object detection portion, and that is operable to calculate a total object distance that is a sum of the distance between the corresponded object and the objects other than the corresponded object;

and

wherein the gain calculation portions calculate the slope gain based on the total object distance.

11. The video signal processing device according to claim 2,

wherein the slope gain creation portions calculate the slope gain in accordance with a property of the object.

12. The video signal processing device according to claim 11,

wherein the property of the object is at least one of the number of detected objects, the size of the object, and the distance from the center of the display screen to the substantially center point of the object.

13. The video signal processing device according to claim 2, further comprising:

a default slope gain creation portion, which includes a central distance calculation portion that is operable to calculate, for each pixel making up the unit image, the distance between the pixel and the display screen center, and a gain calculation portion that is operable to calculate the slope gain in accordance with the distance that is calculated by the central distance calculation portion;

wherein the slope gain joining portion, in a case where not even one object has been detected by the multiple object detection portion, regards the slope gain that has been calculated by the default slope gain creation portion as the correction gain, and in a case where an object has been detected by the multiple object detection portion, joins the slope gain that has been detected by the default slope gain creation portion and the slope gain that has been detected by the slope gain creation portion to create a single correction gain.

14. The video signal processing device according to claim 13,

wherein the slope gain joining portion regards the slope gain that has been calculated by the default slope gain creation portion as the correction gain in a case where the number of objects detected by the multiple object detection portion is equal to or greater than a fixed value.

15. The video signal processing device according to claim 2, further comprising:

a characteristic amount extraction portion that is operable to extract a characteristic amount in the unit image;

wherein the gain calculation portion calculates the slope gain in accordance with the characteristic amount.

16. A video signal display device, comprising the video signal processing device according to claim 1, and a display device operable to display a video signal that is output from the video signal processing device.

17. The video signal processing device according to claim 16,

wherein the display device is a self-emitting type display device that has a power limit portion that is operable to limit the power consumed by the display device when an average picture level of the video signal is equal to or greater than a predetermined value.

18. A video signal processing method of creating a display video signal to be displayed on a light-adjustable display device, comprising:

detecting a plurality of objects that are included in a unit image that is formed by an input video signal;

calculating a correction gain such that when the unit image is displayed on the display device, a point on a display screen at which an emission amount that is lower than the emission amount on the display screen at a point that is substantially in the center between any two objects is in a region between the points substantially in the center of the two objects; and

correcting the input video signal in accordance with the correction gain and outputting the result to the display device as the display video signal.

19. A computer-readable storage medium on which is stored a video signal processing program for creating a display video signal to be displayed on a light-adjustable display device, comprising causing a computer to function as:

a multiple object detection portion operable to detect a plurality of objects that are included in a unit image that is formed by an input video signal;

a correction gain calculation portion operable to calculate a correction gain such that when the unit image is displayed on the display device, a point on a display screen at which an emission amount that is lower than the emission amount on the display screen at a point that is substantially in the center between any two objects is in a region between the points substantially in the center of the two objects; and

a signal level correction portion operable to correct the input video signal in accordance with the correction gain and output the result to the display device as the display video signal.

20. An integrated circuit for creating a display video signal to be displayed on a light-adjustable display device, comprising:

a multiple object detection portion operable to detect a plurality of objects that are included in a unit image that is formed by an input video signal;

a correction gain calculation portion operable to calculate a correction gain such that when the unit image is displayed on the display device, a point on a display screen at which an emission amount that is lower than the emission amount on the display screen at a point that is substantially in the center between any two objects is in a region between the points substantially in the center of the two objects; and

a signal level correction portion operable to correct the input video signal in accordance with the correction gain and output the result to the display device as the display video signal.