Marketech International Corporation

Quanta Computer Incorporated

Tsan-Hung Tsai

Yi-Chia Shan

Hsu-Pin Kao

Hsu-Chia Kao

Yi-Sheng Yu

Kai-Hsiang Hsu

Yu-Wen Huang

This invention provides a system and method for image signal contrast extension and overflow compensation. The system includes contrast extension and overflow compensation look-up tables, an image gray level boundary determining unit, a contrast extension unit, an overflow judging unit, and an overflow compensation unit. The image gray level boundary determining unit defines a maximum and a minimum among the gray levels of the pixels of an image signal and calculates the difference. The contrast extension unit selects corresponding parameter from the contrast extension table for contrast extension of a given image pixel. The overflow judging unit judges whether the pixels are overflowed. The overflow compensation unit compensates the pixel. When a pixel is overflowed, the overflow compensation unit selects, according to the gray level of the pixel, a corresponding overflow compensation parameter to reduce the gray level to overcome the problem of overflow.

System and method for contrast extension adjustment and overflow compensation of image signal

The invention provides a hue adjusting device. When one color axis including different hues is being adjusted by the user, the hue adjusting device will rotate each of the different hue angles in different rotation angles. Accordingly, the color of an image adjusted by the invention will be smoother than the prior art. Namely, the image quality can be improved.

Hue adjusting device

A method for adjusting an image on the basis of characteristics of a display system is provided. The image includes M horizontal lines. Each of the M horizontal lines respectively includes N pixels. Each pixel has an original gray level. A look-up table previously stores a plurality of conversion coefficients related to the characteristics of the display system. The method first calculates an ith loading according to the N original gray levels of the N pixels in the ith horizontal line. Based on the ith loading, an ith conversion coefficient corresponding to the ith loading is selected from the plurality of conversion coefficients in the look-up table. The method respectively multiplies the N original gray levels of the N pixels in the ith horizontal line by the ith conversion coefficient to generate N new gray levels for the N pixels in the ith horizontal line, whereby the image is adjusted.

Apparatus and method for adjusting image on the basis of characteristics of display system

The invention discloses an apparatus for adjusting the brightness of the iimage of an inputted image sequence in a display system. The image sequence includes a plurality of images which each consists of a plurality of pixels. The apparatus includes a first calculating module for calculating a current brightness ratio, a second calculating module for calculating an averaged brightness ratio, a judging module for outputting one selected from the current brightness ratio or the averaged brightness ratio as an outputted brightness ratio, a determining module for storing a plurality of brightness ratios and the corresponding gains and for determining the gain corresponding to the outputted brightness ratio, and an adjusting module for multiplying the gray scale level of each pixel of the iimage by the gain corresponding to the outputted brightness ratio respectively, so as to adjust the brightness of the iimage.

Apparatus and method for adjusting brightness

The invention discloses a hue dividing and judging device including a memory unit, a calculation module, and a judgment module. The memory unit is used for storing a look-up table, and the look-up table records N boundaries, wherein the N boundaries includes j+1 operative boundaries for defining j color areas. The calculation module is used for calculating the hue of each pixel of an input image. According to the look-up table, the judgment module is used for judging where the hue of each pixel falls within two of the operative boundaries, so as to judge that the hue of the pixel of the input image falls into which one of the color areas. Accordingly, if there are more operative boundaries recorded in the look-up table, the hue will be divided into more color areas, and the user will have more choices for adjusting the color of the input image.

Hue diving and judging device

The present invention discloses a method and an apparatus for applying a dynamic contrast expansion technique to plasma display panels through performing a gamma conversion for the inputted image to convert the relationship of the brightness and gray level of the inputted image into a linear relation, performing a subtraction for the gray level value of the image to maintain the image at its smallest color deviation, analyzing the image property histogram to compute the maximum gray level and the minimum gray level required for carrying out the image contrast expansion and obtaining an image contrast expansion gain, and adopting an average of several previously inputted image contrast expansion gains and a current image contrast expansion gain as the contrast expansion gain used in the actual contrast expansion gain formula, so as to compute a new outputted gray level value after the image contrast expansion is performed.

Method and apparatus for dynamic image contrast expansion

The present invention provides a method to automatically regulate brightness of liquid crystal displays (LCDs), which resolves the overload and easy fatigue of human eyes and poor image contrast due to high brightness of the conventional LCD. The present invention includes use of four parts, including an image brightness regulating unit, an image brightness ratio computation and output controlling unit, an ambient light detection and brightness adaptation regulating unit and an image gray level expanding unit. The image signals of an LCD are processed in such a manner to enable automatic control of optical flux of LCD TV by regulating the gray level of output images. Also, optical flux of LCD TV can be automatically controlled with the change of images and ambient light, thus alleviating overburdening of human eyes and improving the contrast and comfort of images for a better visual effect.

Method to automatically regulate brightness of liquid crystal displays

A method for adjusting a target gray level of a target pixel based on a spatial mask is provided. The target pixel is surrounded with N adjacent pixels; each of the N adjacent pixels respectively has an adjacent gray level. The method first multiplies the target gray level with a sharpness index to generate an amplified target gray level and respectively multiplies each of the adjacent gray level with an adjacent index to generate N modified adjacent gray levels. Then, the amplified target gray level and the N modified adjacent gray levels are added up to generate a first gray level sum. The method multiplies the first gray level sum with a multiplying parameter to generate a second gray level sum. At last, the method divides the second gray level sum by a dividing parameter to generate an adjusted gray level for the target pixel.

Apparatus and method for adjusting sharpness of image

The method to reduce image sticking in a plasma display panel (PDP) includes four steps. There is converting a relationship between gray level and brightness of an input signal into a linear relation by a converter. Next, there is recording an image with a static image detector at time t using a frame buffer, and after a period of time &#x394;t, comparing the image at time t with the image at time t+&#x394;t, thereby identifying static or dynamic images in the pixel. Then, there is recording a gain of every pixel by a brightness regulator using an image gains memory buffer zone, the gain being regulated according to detection results of the static image detector. Finally, there is improving gray level performance of output images by a gray level promoter and brightness converter. Thus, method actively detects static pixels and reduces brightness in the static region for minimized image sticking.

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Sanchong, Taiwan

Tsan-Hung Tsai