5-Frame Cycle Based FI-FRC Pixel Dithering Algorithm For TFT-LCD

FRC pixel dithering algorithm was widely used in LCDs as one of color enhancement technologies. For a LCD, the higher bit width input display data means more colors can be expressed. But the bit width of display driver IC is usually limited. The pixel dithering can make LCD display the enough colors as expected with less bit width driver ICs.There are two method to implement dithering algorithm, FRC and Hi-FRC technology,. The former can display total 253 steps grays scale with 6-bit driver IC system,while the latter one can achieve totally 256 steps grays scale display output. Unfortunately , the gray scale shade become unsmooth and FRC induced display antifacts performance will be worsen after Hi-FRC algorithm was applied.The papers would like study the mechanism of above problems and innovate a new algorithm to resolve these problems. The new algorithm is named with Fi-FRC pixel dithering algorithm, which use 5-frame to complete an algorithm cycle. The mathematical models and necessary analysis was hired to verify the reasonableness and possibility of the algorithm. Furthermore, we design the algorithm with HDL and implement it into FPGA to check the actual display performance. As the result of experiments, we have a conclusion that Fi-FRC algorithm is a qualified dithering method to improve both gray scale shade performance and FRC antifacts performance.