Method and apparatus for generating white component and controlling the brightness in display devices

The following is based on Korean Patent Application No. 99-43481 filed Oct. 8, 1999, herein incorporated by reference. A method and apparatus for generating a white signal component and for controlling the brightness of an image are provided. In the above method and apparatus, the brightness increases of Red, Green and Blue, the saturations of which are not decreased from an input image are calculated using a vector, and the minimum value of such increases is utilized as the input value for the white component. Further, by adding brightness control components of RGB color to the input RGB signals, brightness increases in the direction of the original colors instead of the achromatic one are possible, which is the way the white component is added so as to increase the luminance of color display devices representing a color using a color filter such a flat panel display. Accordingly, a color saturation of the image is not decreased even with addition of the achromatic color a component. In other words, in converting a signal from the three colors such as RGB into the four colors inclusive of white component, the present invention is capable of increasing the brightness without reduction of saturation as well as extracting the white component in an easy and efficient way, which enhances the performance of image processing apparatuses such as color display devices and the like.