Patent ID: 9595229
Date: 2017-03-14
CPC Classifications: G09G

Claim:
1. A local dimming method comprising: segmenting an input image into N×M (N and M are positive integer greater than n) blocks; determining representative values of the blocks, which define average luminance of the respective blocks; analyzing the input image; setting a spatial filter mask having a size of n×n (n is a positive integer greater than 3 and equal to or smaller than 10), the spatial filter mask having variable coefficients; changing the variable coefficients of the spatial filter to increase the number and value of coefficients greater than 0 in the spatial filter mask when the input image is determined as a darker image than a previous frame image or a reference image, and to decrease the number and value of coefficients greater than 0 in the spatial filter mask when the input image is determined as a brighter image than the previous frame image or the reference image, the value of coefficients greater than 0 for the brighter image forming a size of k×k and being completely surrounded by value of coefficients equal to 0, wherein k is smaller than n; and multiplying the block representative values by the variable coefficients of the spatial filter mask that have been changed to determine a dimming value for each block, wherein the value of each of the coefficients for the darker image is larger than the value of each of the coefficients for the brighter image in corresponding positions.