Chang-Shuo Wu

Challenge of 3D LCD Displays

A multiview autostereoscopic LCD display with a localized 2D/3D switching function is developed based on the actively switchable parallax barrier technology. This switchable barrier comprises of an electro-optically switchable liquid crystal (LC) and a microretarder. Polymer dispersed liquid crystal (PDLC) with switchable clear and diffusing states and twisted nematic liquid crystal (TNLC) with polarization switching function are used as switching devices. The microretarder is prepared by self-developed multibeam laser scanning process, which is clean, friendly to the environment, and easy for scale up and mass production. The influence factors on the image qualities of 3D displays based on LCD panel technology are analyzed and discussed. Some solutions have proposed to solve the commercial application issues.

A high-resolution autostereoscopic display system with a wide viewing angle using an LCOS projector array

— This study develops an autostereoscopic display based on a multiple miniature projector array to provide a scalable solution for a high-resolution 3-D display with large viewing freedom. To minimize distortion and dispersion, and to maximize the modulation transfer function (MTF) of the projection image to optimize 3-D image quality, a dedicated projection lens and an accurate six-axis adjusting platform for the miniature projector were designed and fabricated. Image-blending technology based on a lookup table was adopted to combine images from 30 miniature projectors into a seamless single image. The result was a 35-in. autostereoscopic display with 60 views ata 30° viewing angle, 90° FOV, and large range of viewing distance. The proposed system exhibits very smooth motion parallax when viewers move around in front of it.

Evaluation of an Eye Tracking Technology for 3D Display Applications

Due to the bandwidth constraints of multi-view autostereoscopic display that severely restrict number of views simultaneously displayed without degrading resolution or increasing display cost unacceptably. The alternative way is the eye tracking technology, which can fluently rendering and accurately projecting the stereo video to the viewer. In order to render stereo content with respect to users view points and to optically project the content onto the left and right eyes of the user accurately, the real-time viewer tracking technique that allows the user to move around freely when watching the autostereoscopic display is developed in this study. It comprises the face detection by using multiple eigenspaces of various lighting conditions, fast block matching for tracking four motion parameters of the users face region. The Edge Orientation Histogram (EOH) on Real AdaBoost to improve the performance of original AdaBoost algorithm using Haar feature in OpenCV library developed by Intel is also applied in this study. Since performance of the viewer tracking autostereoscopic display is still influenced under variant environmental conditions, the robustness and efficiency of the viewer-tracking system are evaluated in this study.

Development of an autostereoscopic display system using projectors array

An autostereoscopic display using multiple miniature projectors array was developed to realize a 3D display system with both high resolution and large number of views. It is found that image distortion of the projection lens, alignment between the projector and the screen, and image blending among tiled images are the three critical technologies in such a system. This paper presents the researches intended to solve the problems and implement a 3D display with wide view angle and smooth parallax transition.

Study of a viewer tracking system with multiview 3D display

An autostereoscopic display provides users great enjoyment of stereo visualization without uncomfortable and inconvenient drawbacks of wearing stereo glasses. However, bandwidth constraints of current multi-view 3D display severely restrict the number of views that can be simultaneously displayed without degrading resolution or increasing display cost unacceptably. An alternative to multiple view presentation is that the position of observer can be measured by using viewer-tracking sensor. It is a very important module of the viewer-tracking component for fluently rendering and accurately projecting the stereo video. In order to render stereo content with respect to users view points and to optically project the content onto the left and right eyes of the user accurately, the real-time viewer tracking technique that allows the user to move around freely when watching the autostereoscopic display is developed in this study. It comprises the face detection by using multiple eigenspaces of various lighting conditions, fast block matching for tracking four motion parameters of the users face region. The Edge Orientation Histogram (EOH) on Real AdaBoost to improve the performance of original AdaBoost algorithm is also applied in this study. The AdaBoost algorithm using Haar feature in OpenCV library developed by Intel to detect human face and enhance the accuracy performance with rotating image. The frame rate of viewer tracking process can achieve up to 15 Hz. Since performance of the viewer tracking autostereoscopic display is still influenced under variant environmental conditions, the accuracy, robustness and efficiency of the viewer-tracking system are evaluated in this study.