19.1: OLED Power Reduction Algorithm Using Gray‐level Mapping Conversion

Abstract

This paper presents a new OLED power reduction algorithm. It computes the optimal power reduction level by modifying the gray-level mapping curve between input and output signals based on the image quality metric. Therefore, it does not need any circuit modification or additional circuits for the power reduction.

Peripheral Dimming: A New Low-Power Technology for OLED Display Based on Gaze Tracking

“…In this section, we compare the proposed method with previous studies, PCCE [11] and two BS [8], [13] methods. The PCCE is one of the most widespread CE techniques, and the two BS techniques presented in [8] and [13] reduce the brightness by modulating the Y (YCbCr) and L* (CIELAB) components, respectively. Because the three methods commonly have a similar approach that reduces the brightness, we chose them for comparison.…”

“…11(f)-11(h) show the distribution of ΔL*. The white, red, green, and blue colored distributions indicate the proposed and previous methods of [11], [8], and [13], respectively. On one hand, in the case of the proposed method, it is observed that a majority of the ΔL* values are zero and are distributed near zero.…”

“…This means that power consumption could be reduced by limiting the luminance. By using this characteristic, hardware-based [5]- [7] and software-based [8]- [17] low-power techniques have been studied. Shin et al [5] proposed a dynamic voltage scaling technique that dynamically changes the supply voltage of an OLED panel to limit the maximum luminance.…”

“…Generally, there is a trade-off between the saved power and image quality, which is a part of the quality of experience (QoE). Some research groups have attempted to optimize the power-saving condition based on the objective image quality assessment (IQA) [8]- [12]. Brightness scaling (BS), which modifies brightness by remapping the gray-level curve, is a typical power-saving solution [8]- [10].…”

“…Some research groups have attempted to optimize the power-saving condition based on the objective image quality assessment (IQA) [8]- [12]. Brightness scaling (BS), which modifies brightness by remapping the gray-level curve, is a typical power-saving solution [8]- [10]. Although the contrast ratio of the image would be reduced in these techniques owing to the decrease in the peak luminance, they minimize image quality degradation by determining the most efficient condition based on the objective IQA.…”