50.3: A Video‐Capable Algorithm for Local Dimming RGB Backlight

Abstract

We present an algorithm for efficient calculation of local dimming RGB LED-Backlight to save power consumption. The algorithm was implemented in hardware to support Full-HD resolution at a low HWcost. It showed clipping-free and video-capable results.

Evaluation of LCD local‐dimming‐backlight system

“…These initially determined that brightness levels can not be imposed to the backlight directly because the brightness of the bright-image area may be insufficient after the light under the bright-image area is diffused to neighboring block areas. So, a backlight optimization algorithm 5,11 is necessary after the initial backlight calculation. In the backlight optimization step, spatial and temporal filters may also be introduced to remove some visual artifacts.…”

“…Several backlight local-dimming systems and algorithms have been reported in the literature. [1][2][3][4][5][6][7][8][9][10][11] These backlight dimming systems have similar goals to reduce the power consumption and increase the static contrast, and each of them claimed their performance on contrast enhancement and power reduction. The problem is that it is difficult to compare these local-dimming systems by their claimed results.…”

P‐56: Application of the SSC Local Dimming Algorithm for an Edge‐Lit TV

“…Since the HW-cost of SSC is proportional to the number of pixels [3] it is worth to reduce the total number of pixels by condensing a cell of (s·t) image pixels to one concentrated pixel. The Clipping Allowance Factor (CAF) which is calculated as function of the maximum gray value of the cell and their average -together with a set of threshold valuesdetermines the concentrated pixel's gray value.…”

“…Because of the unique quality of our already published SSC Algorithm ( [2], [3]) -we approach the local dimming problem in physical direction: calculating a luminance for the LCDs pixels based upon the light spread function (LSF) and the brightness of the LEDs -we are able to determine the LED brightness for any thinkable arrangement of the light sources [5]. The SSC method is to be adapted for the edge-lit structure.…”

67.2: Compensation Methods for Local‐Dimming Backlights with RGB‐LED

“…Recently, in Liquid Crystal Display (LCD) TV industries, the models integrated with a local-dimming backlight system has been increasing their popularity along the tendency of image quality and low power consumption [1][2][3][4][5][6][7]. Optical design is various in each backlight system such that it is necessary to have larger numbers of controllable segmented blocks and narrower luminance distribution of one segmented block to demonstrate the effects of power saving and contrast improvement achieved by local-dimming control.…”