IMAGE DISPLAY DEVICE CAPABLE OF SUPPORTING BRIGHTNESS ENHANCEMENT AND POWER CONTROL AND METHOD THEREOF

• US 20120169797A1
• Filed: 03/12/2012
• Published: 07/05/2012
• Est. Priority Date: 08/26/2005
• Status: Active Grant

• Current Assignee: Chang-Yeong Kim, In-Ji Kim, Seong-Deok Lee, Won-Hee Choe
• Original Assignee: Chang-Yeong Kim, In-Ji Kim, Seong-Deok Lee, Won-Hee Choe
• Inventors: CHOE, Won-hee, Kim, In-Ji, Lee, Seong-deok, Kim, Chang-Yeong
• Granted Patent: US 8,625,894 B2
• Time in Patent Office: Days
• US Class Current: 345/690
• CPC Class Codes: G06T 5/40 using histogram techniques
• CPC Class Codes: G06T 5/92 based on global image properties
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• 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 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336

Abstract

An image display device capable of supporting brightness enhancement and power control and a method thereof, in which the brightness and contrast are enhanced and the power of a light source is controlled in accordance with the image characteristic. In the image display method, a parameter representative of an input image is calculated from a histogram of the input image, a model corresponding to the input image is selected from a plurality of representative models by analyzing the parameter, and then a brightness controlling function matched with the selected model is selected. The size of each component of a pixel constituting the input image is controlled using the brightness controlling function, and the output image of the pixel whose component size has been controlled is displayed.

Claims

1. A method of displaying an image, comprising:

controlling the size of each component of a pixel constituting an input image;

calculating a brightness of the input image and a brightness of an output image of the pixel whose size has been controlled;

calculating a power decrease ratio that can offset a luminance difference between the brightness of the input image and the brightness of the output image; and

displaying the output image based on a light source driven by a power decreased by the power decrease ratio.

2. The method of claim 1, wherein the pixel is composed of red (R), green (G), and blue (B) components.

3. The method of claim 2, wherein the brightness is an average value of gray scale pixel values, which are expressed as averages of the components, through the whole image.

4. The method of claim 3, wherein the calculating the power decrease ratio includes:

calculating a difference between a luminance value corresponding to the brightness of the input image and a luminance value corresponding to the brightness of the output image; and

determining a power required to make the difference equal to a difference between a luminance value corresponding to an initial power and a luminance value corresponding to the power.

5. The method of claim 4, wherein the correlation between the brightness and the luminance value is determined by gamma characteristics of an image display device, and the correlation between the power and the luminance value is determined by power characteristics of the device.

6. A method of displaying an image, comprising:

receiving an input image;

receiving a power decrease ratio from a user;

calculating a brightness of an output image corresponding to the input image, which can offset a luminance decrease ratio decreased depending on the power decrease ratio;

controlling the size of each component of a pixel constituting the input image in accordance with the brightness of the output image; and

displaying the output image of the pixel whose component size has been controlled, based on a light source driven by a power decreased by the power decrease ratio.

7. The method of claim 6, wherein the pixel is composed of red (R), green (G), and blue (B) components.

8. The method of claim 6, wherein the brightness is an average value of gray scale pixel values, which are displayed as averages of the components, through the whole image.

9. The method of claim 6, wherein the calculating the brightness includes:

obtaining a difference between a luminance value corresponding an initial power and a luminance value corresponding to the power decreased from the initial power by the power decrease ratio; and

calculating a brightness of the output image to make the difference equal to a difference between a luminance value corresponding to the brightness of the input image and a luminance value corresponding to the brightness of the output image.

10. The method of claim 6, wherein a correlation between the power and the luminance value is determined by power characteristics of an image display device, and a correlation between the brightness and the luminance value is determined by gamma characteristics of the device.

11. The method of claim 6, wherein the controlling the size of each component includes:

determining a gain K from the brightness of the output image; and

controlling the size of each component in accordance with the determined gain.

12. The method of claim 11, wherein the determining the gain includes:

subtracting the brightness of the input image from the brightness of the output image;

obtaining an average for the input image after substituting a brightness of each pixel constituting the input image for a brightness controlling function; and

dividing the subtracted result by the obtained average.

13. An image display device comprising:

a pixel controller controlling the size of each component of a pixel constituting an input image and calculating a brightness of the input image and a brightness of an output image of the pixel whose size has been controlled;

a power controller calculating a power decrease ratio that can offset a luminance difference between the brightness of the input image and the brightness of the output image;

a light source unit driven by a power decreased by the power decrease ratio; and

an image output unit displaying the output image based on a light source provided from the light source unit.

14. An image display device comprising:

an image input unit receiving an input image;

a power controller receiving a power decrease ratio from a user and calculating a brightness of an output image corresponding to the input image, which can offset a luminance decrease ratio decreased depending on the power decrease ratio;

a pixel controller controlling the size of each component of a pixel constituting the input image in accordance with the brightness of the output image;

a light source unit driven by a power decreased by the power decrease ratio; and

an image output unit displaying the output image of the pixel whose component size has been controlled, based on a light source from the light source unit.