Method and apparatus for adjusting backlight brightness

Abstract

A method for adjusting backlight brightness for an image display device whose backlights are arranged in an M×N, 2-dimensional array, and an apparatus for realizing this are provided. The method comprises a full search step determining the brightness adjustment value for each of the M×N image blocks corresponding to the backlights for the entire input image and selecting a reference block; a partial search step determining the brightness adjustment value for the selected reference block and surrounding blocks thereof for the image frame inputted following the full search step and reselecting a reference block based on the brightness adjustment value of the previous reference block and surrounding blocks thereof; and an adjustment step adjusting brightness of the backlights in accordance with the brightness adjustment value for each block as determined by the full search step and/or partial search step. In accordance with the present invention, it is possible to increase the speed of image analysis for a display that uses backlights. Likewise, controlling the backlight using the characteristics of the analyzed image enables reducing power consumption and increasing the contrast ratio by applying backlight brightness according to the characteristics of the image.