Patent ID: 7944430

Claim:
A method for adjusting backlight brightness in an image display device having a number of backlights arranged as an M×N, 2-dimensional array, the method comprising: a full search step determining the brightness adjustment value for each of the M×N image blocks corresponding to the number of backlights arranged as a M×N, 2-dimensional array, 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; 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 adjusting brightness of the backlights in accordance with the brightness adjustment value for each reference block and surrounding blocks thereof as determined by the partial search step; wherein the full search step is performed for only the first input frame and the frame inputted during each preset period; wherein the partial search step is performed for all other inputted frames; wherein the number of blocks adjusted for brightness determined in the partial search step is less than the number of blocks adjusted for brightness as determined in the full search step.