Display apparatus and control method thereof

1. A display apparatus comprising:

a display;

a storage configured to store output luminance information of a plurality of grayscale values according to brightness information; and

a processor configured to:

obtain a plurality of grayscale adjustment curves based on the output luminance information stored in the storage,

obtain a plurality of calibration effects by applying each of the plurality of grayscale adjustment curves to an input image,

obtain a grayscale adjustment curve corresponding to a maximum calibration effect from among the plurality of calibration effects,

adjust a grayscale of each pixel of the input image based on the obtained grayscale adjustment curve to generate an output image, and

output the output image through the display,

wherein the plurality of calibration effects are based on a change in a dynamic range and a difference in perceived visual sensation.

2. The display apparatus of claim 1 , wherein the processor is further configured to:

obtain a first adjustment image by applying a first grayscale adjustment curve from among the plurality of grayscale adjustment curves to the input image,

obtain a second adjustment image by applying a second grayscale adjustment curve from among the plurality of grayscale adjustment curves to the input image,

obtain a first dynamic range according to a first predicted output luminance corresponding to brightness information of the first adjustment image,

obtain a second dynamic range according to a second predicted output luminance corresponding to brightness information of the second adjustment image,

obtain a first dynamic range change by comparing the first dynamic range and an input dynamic range of the input image, and

obtain a second dynamic range change by comparing the second dynamic range ranges and the input dynamic range of the input image.

3. The display apparatus of claim 2 , wherein the processor is further configured to:

calculate a first visual sensation difference based on the input image and the first grayscale adjustment curve,

calculate a second visual sensation difference based on the input image and the second grayscale adjustment curve,

obtain a first calibration effect based on the first visual sensation difference and the first dynamic range change,

obtain a second calibration effect based on the second visual sensation difference and the second dynamic range change, and

identify one from among the first calibration effect and the second calibration effect as the maximum calibration effect.

4. The display apparatus of claim 3 , wherein the processor is further configured to:

obtain the first calibration effect by applying a first weight to the first dynamic range change and a second weight to the first visual sensation difference, and

obtain the second calibration effect by applying the first weight to the second dynamic range change and the second weight to the second visual sensation difference.

5. The display apparatus of claim 1 , wherein the output luminance information of the plurality of grayscale values according to the brightness information of the input image indicates maximum output luminance information of each pixel according to the brightness information of the input image, and is calculated based on power consumption of the display apparatus.

6. The display apparatus of claim 1 , wherein the plurality of grayscale adjustment curves comprises a first tone mapping curve and a second tone mapping curve.

7. The display apparatus of claim 6 , wherein the first tone mapping curve and the second tone mapping curve are expressed by a following equation, and have different ω values:

t

i

=

255

×

(

i

255

)

(

1

+

ω

)

where i indicates a grayscale of a pixel included in the input image, ω is an adjustment value, and t i is a grayscale of an adjustment image.

8. The display apparatus of claim 1 , wherein the brightness information indicates an average picture level (APL) of grayscale values of each pixel of the input image.

9. The display apparatus of claim 1 , wherein the processor is further configured to output the output image through the display according to the adjusted grayscale of each pixel.

10. A control method of controlling a display apparatus, the control method comprising:

obtaining a plurality of grayscale adjustment curves based on output luminance information stored in a storage of the display apparatus;

obtaining a plurality of calibration effects by applying each of the plurality of grayscale adjustment curves to an input image;

obtaining a grayscale adjustment curve corresponding to a maximum calibration effect from among the plurality of calibration effects;

adjusting a grayscale of each pixel of the input image based on the obtained grayscale adjustment curve to generate an output image; and

outputting the output image,

wherein the plurality of calibration effects are based on a change in a dynamic range and a difference in perceived visual sensation.

11. The control method of claim 10 , wherein the obtaining the plurality of calibration effects further comprises:

obtaining a first adjustment image by applying a first grayscale adjustment curve from among the plurality of grayscale adjustment curves to the input image;

obtaining a second adjustment image by applying a second grayscale adjustment curve from among the plurality of grayscale adjustment curves to the input image;

obtaining a first dynamic range according to a first predicted output luminance corresponding to brightness information of the first adjustment image;

obtaining a second dynamic range according to a second predicted output luminance corresponding to brightness information of the second adjustment image;

obtaining a first dynamic range change by comparing the first dynamic range and an input dynamic range of the input image; and

obtaining a second dynamic range change by comparing the second dynamic range and the input dynamic range of the input image.

12. The control method of claim 11 , wherein the obtaining the plurality of calibration effects further comprises:

calculating a first visual sensation difference based on the input image and the first grayscale adjustment curve;

calculating a second visual sensation difference based on the input image and the second grayscale adjustment curve; and

obtaining a first calibration effect based on the first visual sensation difference and the first dynamic range change; and

obtaining a second calibration effect based on the second visual sensation difference and the second dynamic range change, and

wherein the obtaining the grayscale adjustment curve corresponding to the maximum calibration effect further comprises identifying one from among the first calibration effect and the second calibration effect as the maximum calibration effect.

13. The control method of claim 12 , wherein the obtaining the plurality of calibration effects comprises:

obtaining the first calibration effect by applying a first weight to the first dynamic range change and a second weight to the first visual sensation difference; and

obtaining the second calibration effect by applying the first weight to the second dynamic range change and the second weight to the second visual sensation difference.

14. The control method of claim 10 , wherein the output luminance information indicates maximum output luminance information of each pixel according to the brightness information of the input image, and is calculated based on power consumption of the display apparatus.

15. The control method of claim 10 , wherein the plurality of grayscale adjustment curves comprises a first tone mapping curve and a second tone mapping curve.

16. The control method of claim 15 , wherein the first tone mapping curve and the second tone mapping curve are expressed by a following equation, and have different ω values:

t

i

=

255

×

(

i

255

)

(

1

+

ω

)

where i indicates a grayscale of a pixel included in the input image, ω is an adjustment value, and t i is a grayscale of an adjustment image.

17. The control method of claim 10 , wherein the brightness information indicates an average picture level (APL) of grayscale values of each pixel of the input image.

18. The control method of claim 10 , wherein the outputting comprises outputting the output image according to the adjusted grayscale of each pixel.

19. A non-transitory computer-readable medium which stores computer instructions to control a display apparatus to perform an operation when executed by a processor of the display apparatus, the operation comprising:

obtaining a plurality of grayscale adjustment curves based on output luminance information;

obtaining a plurality of calibration effects by applying the plurality of grayscale adjustment curves to an input image;

obtaining a grayscale adjustment curve corresponding to a maximum calibration effect from among the plurality of calibration effects;

adjusting a grayscale of each pixel of the input image based on the obtained grayscale adjustment curve to generate an output image; and

controlling a display of the display apparatus to output the output image,

wherein the plurality of calibration effects are based on a change in a dynamic range and a difference in perceived visual sensation.