Presentation of a Three-Dimensional Image by Rotating Pepper’s Ghost

Abstract

In this research, we present a three-dimensional image of a Pepper’s Ghost, and simultaneously observed from multiple angles by rotating it. Pepper’s Ghost is a technique used to produce aerial images by combining the image reflected on a transparent plate with the background. A three-dimensional image is presented at the center of the rotation by rotating the transparent plate and displaying the image according to its orientation. The proposed system consists of a display placed on its side, transparent plate with a privacy filter attached to it, and motor. The top and bottom of the pyramid-shaped transparent plate, which is often used for the Pepper’s Ghost exhibit, are switched to show a three-dimensional image. A PI-controlled motor is used to rotate the transparent plate and facilitate observation from multiple angles by following the images. Because the horizontal viewing angle of Pepper’s Ghost exceeds 45 degrees, the image of the neighboring surface will appear to leak when the surfaces are adjacent. Therefore, we used a privacy filter to reduce the leakage of images from neighboring surfaces. We use a 240-fps display as the video playback device and present several images on a rotating the pyramid-shaped transparent plate.

Experimental results indicate a trade-off between the clarity of the 3D image and eye strain depending on the rotation speed.