Chang-Mo Yang

Simulation of Blur in Transmitted Image through Transparent Plastic for Transparent OLEDs

Transparent displays have received attention as next-generation displays. When attached to transparent displays, transparent plastics can control transmission of incident lights. They can extend the use of transparent displays to various applications. The transmitted image of the background through the transparent plastic appears blurred due to the light diffusion. Major factors affecting this blurriness include the haze and background distance. In this paper, the degree of blurriness in the transmitted image is modelled by the Gaussian blur kernel. With a small set of measurements from the black-and-white patch, the standard deviations of the Gaussian blur kernel and luminance transition curves can be determined for all of the combinations of the haze and background distance. Experimental results indicate that the proposed method accurately estimates the degree of blurriness.

Content-Dependent Reduction of Static Color Breakup on Field Sequential Color LCDs

Field sequential color (FSC) LCDs form color images by sequentially displaying subfield images. Because color filter attenuating light transmission is not required, FSC LCDs can reduce power consumption considerably. However, their sequential display scheme results in undesirable color artifacts that degrade the perceived image quality. This paper proposes a new content-dependent static color breakup (CBU) reduction method for FSC LCDs with 240-Hz frame rate. In addition, two performance indices are defined to examine the effectiveness of the backlight color selections. Experimental results indicate that the proposed method effectively reduces the visibility of static CBU.

A camera-based color calibration of tiled display systems under various illumination environments

ABSTRACT Tiled display systems are widely utilized for digital signage application exceeding the size of a single flat-panel display. Smoothly varying spatial non-uniformity in luminance and color may cause visible difference in the boundary of two adjacent sub-displays. It is necessary to suppress such visible artifacts. Tiled display systems can be installed under various illumination environments and require routine color calibration to compensate for temporal change in display characteristics. This paper presents a simple and cost-effective color calibration method for tiled display systems. Consumer-level digital camera is utilized as a measuring device after the proposed vignetting correction was applied. Experimental results indicate that the proposed color calibration method for tiled display system is quite effective in suppressing the visible artifacts across two adjacent sub-displays.