Power-Constrained Contrast Enhancement for Emissive Displays Based on Histogram Equalization

Abstract

A power-constrained contrast-enhancement algorithm for emissive displays based on histogram equalization (HE) is proposed in this paper. We first propose a log-based histogram modification scheme to reduce overstretching artifacts of the conventional HE technique. Then, we develop a power-consumption model for emissive displays and formulate an objective function that consists of the histogram-equalizing term and the power term. By minimizing the objective function based on the convex optimization theory, the proposed algorithm achieves contrast enhancement and power saving simultaneously. Moreover, we extend the proposed algorithm to enhance video sequences, as well as still images. Simulation results demonstrate that the proposed algorithm can reduce power consumption significantly while improving image contrast and perceptual quality.

Technologies based on energy savings for OLED devices

“…It is used to enhance power consumption by reducing it while viewing the most improved photo in terms of brightness and details on an OLED display [15]. This display's total dissipated power (TDP) that has N pixels is expressed according to [4,19,20] as follows:…”

“…In terms of video displaying, an experiment was applied for two movies which are 'The Shawshank Redemption' and 'Avatar' [26]. An average luminance with the value of R in the ACE network was employed for the frame of the input video.…”

“…As shown in Figure 6, the optical comparison is made between four methods, three of them are conventional and the fourth one is the proposed method. In Figure 6, (a) is the input image, (b) is HPCCE [4], (c) is Chang et al [37], (d) is Chondro et al [5], and (e) is the proposed method [15]. By comparing the produced images, we can easily notice that the proposed method has the best result by preserving the details of the image and improving the contrast for the fixed value of (R).…”

“…Also, transparent OLED display (TOLED) was presented lately, as many companies started to merge it in their goods like military products, vehicle construction, and other industries [2]. To decrease the power consumption in OLED displays, some methods were made in terms of hardware enhancement and image processing [3,4,5]. This review paper talks about the next methods, Unsupervised PCCE Technique, Region Of Interest (ROI) Extraction & Region Of Noninterest (NON-ROI) Dimming, A Web Browser For Mobile OLED Displays; Chameleon, and Darkening OLED Display Partially, that were used to achieve the desired goal.…”

Method of Improved Fuzzy Contrast Combined Adaptive Threshold in NSCT for Medical Image Enhancement

“…Numerous approaches for modifying histogram based contrast enhancement have been proposed in order to limit the level of enhancement. These modifications include automatic image equalization using Gaussian mixture modeling [3], power-constrained contrast enhancement based on histogram equalization [4], and entropy maximization histogram modification for image enhancement [5]. The retinex theory was originally proposed by Land and is based on the human visual system [6].…”