An Adaptive Global LED Backlight Dimming for Contrast Enhancement and Power Reduction

Abstract

The paper proposes a global backlight dimming algorithm for CR enhancement and power reduction. S-shaped function is involved to help improve CR. Both the backlight dimming level and the turning point grayscale of the s-shaped curve are determined by the histogram of the input image. The pixels with the grayscales more than the turning point are compensated to become brighter and the pixels less than turning point become darker. The simulation results show that the proposed dimming algorithm can improve CR by average 34.95% and reduce power consumption by 11.30%.

An Optimized Backlight Local Dimming Algorithm for Edge-Lit LED Backlight LCDs

“…Also, the user-defined brightness of the device was set to 1.0. To evaluate performance, we calculated the average power consumption for the test image set after backlight local dimming as follows: (18) where is the number of images in the test image set and is the power of the -th LED at the -th image. Also, we calculated the average PSNR for the test image set to compare the distortion to the previous methods and this can be expressed as follows: (19) where denotes the mean square error (MSE) value at the -th image.…”

“…Existing backlight dimming algorithms can be grouped into global and local dimming approaches. First, the global dimming approaches [14]- [18] set the power of all the LEDs to the same value. They used a histogram of luminance values [14]- [17] and low-level features such as the average and maximum luminance pixel values [18].…”

Research and Evaluation of Local Dimming Algorithm for LED Backlight LCD Display

“…The maximum value in all G avg-block (i, j) is named as G max-block and minimum value is G min-block , the contrast ratio is shown in the Eq. 3.…”

“…The dynamic dimming is defined as the dynamic control of the backlight luminance according to the display images. It is helpful to decrease the power consumption and improve the contrast ratio [3]. The dynamic dimming technology is divided into global dimming and local dimming.…”

Image-classification-based global dimming algorithm for LED backlights in LCDs

“…The luminance of a BLU is constant, which means the power is consumed even displaying a completely dark image. Backlight dimming technologies can help improve the 2 problems [1][2][3][4][5][6][7][8][9][10][11][12].…”