IMAGE PROCESSING METHOD FOR DISPLAY APPARATUS AND IMAGE PROCESSING APPARATUS

• US 20140285477A1
• Filed: 03/24/2014
• Published: 09/25/2014
• Est. Priority Date: 03/25/2013
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Cho, Byoungchul, Gong, Namyong, Park, Sangjae
• Granted Patent: US 9,520,075 B2
• Time in Patent Office: Days
• US Class Current: 345/207
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2340/06 Colour space transformation
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 2360/145 the light originating from the display screen
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 5/02 characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 5/06 using colour palettes, e.g. look-up tables
• CPC Class Codes: G09G 5/10 Intensity circuits

Abstract

An image processing method and apparatus using the image processing method are provided. The apparatus comprises a processor configured to scale color values of input image data, thereby simulating the optical characteristics of paper. The simulation takes into consideration varying ambient light conditions around the display to imitate the optical characteristics of physical paper in the same ambient light conditions.

Claims

1. A method for simulating paper-like images on a display, comprising;

measuring one or more ambient light characteristics from one or more sensors;

determining maximum brightness values for red, green and blue (RGB) sub-pixels of a display pixel based on a light reflectance rate of a paper type and the ambient light characteristics;

determining minimum brightness values for the RGB sub-pixels of the display pixel based on a light reflectance rate of an ink type and the ambient light characteristics;

scaling red, green and blue (RGB) color values of image data associated with the sub-pixels of each of the display pixels in reference to the maximum brightness values and the minimum brightness values; and

activating each of the display pixels using the scaled RGB color values of the image data.

2. The method of claim 1, wherein the maximum brightness values and the minimum brightness values for the RGB sub-pixels are generated by:

converting the one or more ambient light characteristics into a normalized set of RGB color values of ambient light;

applying the light reflectance rate of the paper type to each of the normalized RGB color values of the ambient light; and

applying the light reflectance rate of the ink type to each of the normalized RGB color values of the ambient light.

3. The method of claim 1, wherein the ambient light characteristics include an illuminance of the ambient light, and wherein the scaled RGB color values of the image data are compensated with a preset value for the display to maintain a minimal luminance when the illuminance of the ambient light is below a threshold value.

4. The method of claim 1, further comprising:

receiving application information indicative of a type of display content; and

activating each of the display pixels using the scaled RGB color values of the image data when the type of display content is a text oriented content.

5. The method of claim 4, wherein the application information includes information indicative of a size and a location of the display content when the type of display content is the text oriented content, and wherein each of the display pixels in a part of the display corresponding to the text oriented content is activated with the scaled RGB color values.

6. The method of claim 1, wherein scaling the color values of the image data is performed based on the following equation (7), equation (8) and equation (9):

7. The method of claim 1, wherein the ambient light characteristics include intensity of RGB in the ambient light, and wherein scaling the color values of the image data is performed based on a look up table (LUT) including a range of scaled RGB values corresponding to a range of the intensity of RGB in the ambient light.

8. The method of claim 7, wherein the intensity of RGB is calculated based on an illumination value and a color temperature value of the ambient light measured by said one or more sensors.

9. The method of claim 1, further comprising:

adjusting the red, the green and the blue color values of image data associated with the sub-pixels of each of the display pixels based on texture of the paper type.

10. The method of claim 1, wherein the one or more ambient light characteristics includes an illumination value and a color temperature value of the ambient light, and wherein the illumination value and the color temperature value are estimated based on the current time and the current weather condition at the current position of the display.

11. A display, comprising;

a plurality of display pixels, each of the pixels having red, green and blue (RGB) sub-pixels;

one or more sensors for measuring one or more ambient light characteristics; and

a processor configured to;

determine maximum brightness values for the RGB sub-pixels of the display pixel based on a light reflectance rate of a paper type and the measured ambient light characteristics;

determine minimum brightness values for the RGB sub-pixels of the display pixel based on a light reflectance rate of an ink type and the ambient light characteristics;

scale red, green and blue (RGB) color values of image data associated with the respective RGB sub-pixels of each of the display pixels in reference to the maximum brightness values and the minimum brightness values; and

activate each of the display pixels using the scaled RGB color values of the image data.

12. The display of claim 11, wherein processor is configured to convert the one or more ambient light characteristics into a normalized set of RGB color values, and to apply the light reflectance rate of the paper type to each of the normalized RGB color values of the ambient light to calculate the maximum brightness values, and to apply the light reflectance rate of the ink type to each of the normalized RGB color values of the ambient light to calculate the minimum brightness values for the RGB sub-pixels.

13. The display of claim 11, wherein the processor is configured to receive application information indicative of a type of display content, and to activate each of the display pixels using the scaled RGB color values of the image data when the type of display content is a text oriented content.

14. The display of claim 13, wherein the processor is configured to identify a size and a location of the display content when the type of display content is the text oriented content, and to activate each of the display pixels in a part of the display corresponding to the text oriented content with the scaled RGB color values.

15. The display of claim 11, wherein the processor is configured to scale the color values of the image data according to the following equation (7), equation (8) and equation (9):

16. The display of claim 11, wherein said one or more sensors are configured to measure intensity of RGB in the ambient light, and wherein the processor is configured to scale the color values of the image data using a look up table (LUT) including a range of scaled RGB values corresponding to a range of the intensity of RGB in the ambient light.

17. The display of claim 16, wherein the processor is configured to convert the measured intensity of RGB in the ambient light by said one or more sensors to be applicable to the LUT.

18. The display of claim 11, wherein the processor is configured to further adjust the scaled RGB color values based on a texture of the paper type.

19. The display of claim 11, wherein the processor is configured to estimate an illumination value and a color temperature value based on the current time and the current weather condition at the current position of the display, and to determine maximum and minimum brightness values for the RGB sub-pixels based on the estimated illumination value and the estimated color temperature value of the ambient light.

20. A semiconductor chip, configured to adaptively adjust image data based on red, green and blue (RGB) color values that are scaled in reference to maximum brightness values and minimum brightness values for red, green and blue (RGB) sub-pixels, wherein the maximum brightness values and the minimum brightness values based on one or more ambient light characteristics with respect to a light reflectance rate of a paper type and an ink type, respectively.