Michio Oikawa

41.2: Autostereoscopic Display Based on Enhanced Integral Photography Using Overlaid Multiple Projectors

We constructed an autostereoscopic display based on enhanced IP using overlaid multiple projectors. The display provides autostereoscopic images whose resolution is greater than SVGA in an 800 by 400 mm area. Tilting the display surface increases the depth of the autostereoscopic images. We also constructed equipment for calibrating the display.

Full-parallax autostereoscopic display with scalable lateral resolution using overlaid multiple projection

— A method to increase the viewing resolution of an autostereoscopic display without increasing the density of microlenses is proposed. Multiple projectors are used for the projection images to be focused and overlaid on a common plane in the air behind the microlens array. The multiple overlaid projection images yield multiple light spots inside the region of each elemental lenslet of the microlens array. This feature provides scalable high-resolution images by increasing the number of projectors. Based on the proposed method, a prototype display that includes 15 projectors was designed and built. 3-D images were successfully reproduced on the prototype display with full parallax and a wide viewing angle of 70°.

Intra-operative guidance with real-time information of open MRI and manipulators using coordinate-integration module

Assuming the surgery under open magnetic resonance imaging (MRI) equipment with manipulators, we developed the coordinate-integration module and the real-time functions that could display the manipulators position on the volume data of MRI and could obtain the cross-section images of MRI at the manipulators position. The small field of view from an endoscope is the problem in most of the minimally invasive surgeries with manipulators. Therefore, we propose an endoscopic surgery with manipulators under open MRI equipment. The coordinate-conversion parameters were calculated in the coordinate-integration module by calibration with an optical tracking system and markers. The delay of the manipulator-position display on the volume data was approximately within 0.5 second though it depended on the amount of the volume data. We could also obtain the cross-section images of MRI at the manipulators position using the information from the coordinate-integration module. With these functions, we can cope with the change of the organ shape during surgery with the guidance based on the individual information. Furthermore, we can use the manipulator as an MRI probe to define cross-section position like an ultrasonic probe.

A non-uniform SEM contour sampling technique for OPC model calibration

OPC model calibration techniques that use SEM contours are a major reason for the modern day improved fitting efficiency in complex mask design compared to conventional CD-based calibration. However, contour-based calibration has a high computational cost and requires a lot of memory. To overcome this problem, in conventional contour-based calibration, the SEM contour is sampled uniformly at intervals of several nanometers. However, such sparse uniform sampling significantly increases deviations from real CD values, which are measured by CD-SEM. We also have to consider the shape errors of 2D patterns. In general, the calibration of 2D patterns requires higher frequency sampling of the SEM contour than 1D patterns do. To achieve accurate calibration results, and while considering the varied shapes of calibration patterns, it is necessary to set precise sampling intervals of the SEM contour. In response to these problems, we have developed a SEM contour sampling technique in which contours are sampled at a non-uniform rate with arbitrary mask shapes within the allowable sampling error. Experimental results showed that the sampling error rate was decreased to sub-nm when we reduced the number of contour points.

Interactive autostereoscopic display with 60 ray directions

We need to design some parameters to determine the specifications of the IP display. The parameters are lens pitch, pixel density of 2D display, lens focus, lens layout, color filter layout of the display, and so on. We think that the maximal spatial frequency and the number of rays are the most important properties needed to produce realistic autostereoscopic images. Therefore, we must decide which parameters to use to increase the number of rays and the maximal spatial frequency. The lens pitch usually determines the maximal spatial frequency of the IP displays. Whereas, the lens pitch and the pixel density of the 2D display determine the number of rays for IP displays. As there is a trade-off between the lens pitch and the pixel density, we must first decide minimum resolution of the IP display, and then decide the lens pitch and the pixel density of the 2D display.

Integral videography of high-density light field with spherical layout camera array

We propose a spherical layout for a camera array system when shooting images for use in Integral Videography (IV). IV is an autostereoscopic video image technique based on Integral Photography (IP) and is one of the preferred autostereoscopic techniques for displaying images. There are many studies on autostereoscopic displays based on this technique indicating its potential advantages. Other camera arrays have been studied, but their purpose addressed other issues, such as acquiring high-resolution images, capturing a light field, creating contents for non-IV-based autostereoscopic displays and so on. Moreover, IV displays images with high stereoscopic resolution when objects are displayed close to the display. As a consequence, we have to capture high-resolution images in close vicinity to the display. We constructed the spherical layout for the camera array system using 30 cameras arranged in a 6 by 5 array. Each camera had an angular difference of 6 degrees, and we set the cameras to the direction of the sphere center. These cameras can synchronously capture movies. The resolution of the cameras is a 640 by 480. With this system, we determined the effectiveness of the proposed layout of cameras and actually captured IP images, and displayed real autostereoscopic images.

50.1: Invited Paper: Sample Applications Suitable for Features of Integral Videography

I will discuss the features and suitable application for the Integral Videography (IV) display that we developed comparing with two other types of autostereoscopic displays. I will also describe two sample applications that utilize the natural and intuitive 3D expression of the display.

Multiperspective rendering for anime-like exaggeration of joint models

In this paper, representing view-dependent deformation of the perspective effect with a multi-perspective approach is discussed. Traditional hand-drawn animation often constructs a more flexible and impressive depiction than that of computer graphics. Among deformations in handmade drawing, anime has traditionally used deformed depictions that are used to exaggerate the effect of perspective in order to exaggerate the posture of a figure into stylish and dramatic distortions. However, in terms of 3D geometry, the depiction may contain a few contradictions between each part of the body and the background.

Analysis for reproduced light field of 3D displays

A method has been developed for analyzing the characteristics of light fields reproduced by 3D displays and for determining the maximum depth of images on a 3D display. Use of this method will enable identification of which type of 3D display is best for certain applications and will facilitate the design 3D displays.

Multiple multiperspective rendering for autostereoscopic displays

Autostereoscopic displays, which do not require special glasses or lighting conditions but use selector screen methods such as parallax barriers, lenticular sheets, and lens arrays, show attractive 3D scenes. However these methods sometimes fail to separate each image because of a lack of display resolution or insufficient lens quality. This disarrangement is more highly visible especially at the viewing areas more distant from the actual display plane, where binocular disparity causes much discrepancy of images. Currently, most graphic designers manage to develop scenes by using heuristic procedures in accordance with the limitations of each display system.