Image compensation method applied to display and associated control circuit
A control circuit applied to a display includes an adjustment parameter generating circuit, an adjustment circuit, a compensation circuit, an image detail compensating circuit and an output circuit. The adjustment parameter generating circuit determines an adjustment parameter according to a backlight intensity corresponding to a pixel in a frame. The adjustment circuit adjusts a pixel value of the pixel according to the adjustment parameter to generate an adjusted pixel value. The compensation circuit compensates the adjusted pixel value according to a compensation curve go generate a compensated pixel value. The compensation curve includes a non-linear segment. The image detail compensating circuit generates a detail compensation value according to an edge factor of the pixel. The output circuit adjusts the compensated pixel value according to the detail compensation value to generate an output pixel value of the pixel.
1. A control circuit, applied to a display, comprising:
an adjustment parameter generating circuit, determining an adjustment parameter according to a backlight intensity corresponding to a pixel in a frame; wherein:
when the adjustment parameter is greater than a predetermined value, the compensation circuit compensates the adjusted pixel value according to a first curve corresponding to the secondary-curve part of the compensation curve; and
when the adjustment parameter is smaller than the predetermined value, the compensation circuit compensates the adjusted pixel value according to a second curve corresponding to the secondary-curve part of the compensation curve;
an adjustment circuit, adjusting a pixel value of the pixel according to the adjustment parameter to generate an adjusted pixel value; and
a compensation circuit, compensating the adjusted pixel value according to a compensation curve to generate a compensated pixel value for transmission of the compensated pixel value to the display to display the pixel;
wherein, the compensation curve comprises a straight-line part and a secondary-curve part.
2. The control circuit according to claim 1 , wherein
when the pixel value is between 0 to (α*m), the compensation circuit compensates the adjusted pixel value according to the straight-line part of the compensation curve; when the pixel value is between (α*m) to 1 and (1/m) is greater than (2−α), the compensation circuit compensates the adjusted pixel value according to a first curve corresponding to the secondary-curve part of the compensation curve; and
when the pixel value is between (α*m) to 1 and (1/m) is smaller than (2−α), the compensation circuit compensates the adjusted pixel value according to a second curve corresponding to the secondary-curve part of the compensation curve, m is the adjustment parameter, α is a predetermined value, and α and m are real numbers.
3. The control circuit according to claim 1 , wherein the compensation circuit uses
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as an equation of the first curve, and uses
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as an equation of the second curve, where x is the pixel value of the pixel, and α and m are real numbers.