System and method for modulating backlight
First Claim
1. A system for modulating backlight, comprising:
- a light source module providing backlight for a display panel and forming a plurality of illumination areas corresponding to a display area of the display panel, wherein the illumination areas are adjacent to each other and substantially cover the display area;
an image mapping unit performing a transformation on an image displayed on the display panel to convert a RGB color model of the image to another color model independent of an image processing device to acquire an original brightness factor for each pixel of the image;
a histogram analysis unit summing up the amount of total pixels of each illumination area and calculating the amount of accumulated pixels in each illumination area reaching a preset ratio to acquire a reference brightness for each illumination area;
a backlight dimming unit calculating a backlight dimming ratio and a mapping calibration curve of each illumination area according to the reference brightness of each illumination area, wherein the backlight dimming ratio BD(n) of the nth illumination area satisfies the following criterion;
BD(n)=Var+[ABL_(n)/(ABLMAX/(1−
Var))],where Var is a variable larger than 0 and smaller than 1, ABL_(n) is the reference brightness of the nth illumination area and ABLMAX is the maximum reference brightness;
when the light source module comprises Na light sources to divide the display area into (Na+1) illumination areas, if each illumination area is distributed with Np scan lines, the slope of the mapping calibration curve of all the Np scan lines in the first illumination area is the inverse of the backlight dimming ratio of the first light source, the slope of the mapping calibration curve of all the Np scan lines in the (Na+1)th illumination area is the inverse of the backlight dimming ratio of the Nath light source and the slope S(m,n) of the mapping calibration curve of the mth scan lines in the nth illumination area of the 2nd to (Na)th illumination areas satisfies the following criterion;
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Abstract
A backlight modulation system includes a light source module, an image mapping unit, a histogram analysis unit, a backlight dimming unit, and an image reconstruction unit. An active display area of a panel is divided into multiple illumination areas. The image mapping unit performs an RGB-to-YUV transformation to acquire an original brightness factor for each pixel. The histogram analysis unit sums up the amount of pixels reaching a preset ratio in each illumination area to acquire reference brightness for each illumination area. The backlight dimming unit calculates out a dimming ratio and a reset brightness model according to the reference brightness. The image reconstruction unit resets original brightness factor of each pixel into an output brightness factor according to the reset brightness model, and outputs an image for an illumination area according to the output brightness factor and input image data.
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Citations
16 Claims
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1. A system for modulating backlight, comprising:
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a light source module providing backlight for a display panel and forming a plurality of illumination areas corresponding to a display area of the display panel, wherein the illumination areas are adjacent to each other and substantially cover the display area; an image mapping unit performing a transformation on an image displayed on the display panel to convert a RGB color model of the image to another color model independent of an image processing device to acquire an original brightness factor for each pixel of the image; a histogram analysis unit summing up the amount of total pixels of each illumination area and calculating the amount of accumulated pixels in each illumination area reaching a preset ratio to acquire a reference brightness for each illumination area; a backlight dimming unit calculating a backlight dimming ratio and a mapping calibration curve of each illumination area according to the reference brightness of each illumination area, wherein the backlight dimming ratio BD(n) of the nth illumination area satisfies the following criterion;
BD(n)=Var+[ABL_(n)/(ABLMAX/(1−
Var))],where Var is a variable larger than 0 and smaller than 1, ABL_(n) is the reference brightness of the nth illumination area and ABLMAX is the maximum reference brightness;
when the light source module comprises Na light sources to divide the display area into (Na+1) illumination areas, if each illumination area is distributed with Np scan lines, the slope of the mapping calibration curve of all the Np scan lines in the first illumination area is the inverse of the backlight dimming ratio of the first light source, the slope of the mapping calibration curve of all the Np scan lines in the (Na+1)th illumination area is the inverse of the backlight dimming ratio of the Nath light source and the slope S(m,n) of the mapping calibration curve of the mth scan lines in the nth illumination area of the 2nd to (Na)th illumination areas satisfies the following criterion; - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method for modulating backlight, comprising:
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forming a plurality of illumination areas corresponding to a display area of a display panel, wherein the illumination areas are adjacent to each other and substantially cover the display area; transforming a RGB color model of an image to be displayed on the display panel into another color model independent of an image processing device to acquire an original brightness factor for each pixel; summing up the amount of total pixels of each illumination area and calculating the amount of accumulated pixels in each illumination area reaching a preset ratio to acquire a reference brightness for each illumination area; calculating out a backlight dimming ratio and a reset brightness model for each illumination area according to the reference brightness of each illumination area; resetting the original brightness factor of each pixel into an output brightness factor according to the reset brightness model; and outputting an image for the corresponding illumination area according to the output brightness factor and input image data, wherein the backlight dimming ratio BD(n) of the nth illumination area satisfies the following criterion;
BD(n)=Var+[ABL_(n)/(ABLMAX/(1−
Var))],where Var is a variable larger than 0 and smaller than 1, ABL_(n) is the reference brightness of the nth illumination area and ABLMAX is the maximum reference brightness;
the light source module comprises Na light sources to divide the display area into (Na+1) illumination areas, if each illumination area is distributed with Np scan lines, the slope of the mapping calibration curve of all the Np scan lines in the first illumination area is the inverse of the backlight dimming ratio of the first light source, the slope of the mapping calibration curve of all the Np scan lines in the (N2+1)th illumination area is the inverse of the backlight dimming ratio of the Nath light source and the slope S(m,n) of the mapping calibration curve of the mth scan lines in the nth illumination area of the 2nd to (Na)th illumination areas satisfies the following criterion; - View Dependent Claims (12, 13, 14, 15, 16)
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Specification