Recently, people, who consume digital video or image, require more realistic digital contents. That's why HDR (High Dynamic Range) device is getting popular. HDR device captures and generates high dynamic range contents and display it to make the consumer feel more realistic. But, we have still problem, how to express legacy contents, which were captured and generated by LDR (Low Dynamic Range) devices, more realistic for LDR mobile display. In this paper, we propose a new method to express LDR contents more realistic in the mobile device. We proposed to increase peak-luminance for OLED using "Loading Effect" phenomenon. Analyzing visually important regions in the contents based on human visual perception, the luminance in those regions can be controlled easily. HDR contents can be converted more realistic in OLED display by proposed method.