We propose a method to increase the viewing resolution of an autostereoscopic display without increasing the density of
microlenses. 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.
We developed a mobile-size integral videography (IV) display that reproduces 60 ray directions. IV is an autostereoscopic
video image technique based on integral photography (IP). The IV display consists of a 2-D display
and a microlens array. The maximal spatial frequency (MSF) and the number of rays appear to be the most
important factors in producing realistic autostereoscopic images. Lens pitch usually determines the MSF of IV
displays. The lens pitch and pixel density of the 2-D display determine the number of rays it reproduces. There
is a trade-off between the lens pitch and the pixel density. The shape of an elemental image determines the shape
of the area of view.
We developed an IV display based on the above correlationship. The IV display consists of a 5-inch 900-dpi
liquid crystal display (LCD) and a microlens array. The IV display has 60 ray directions with 4 vertical rays and
a maximum of 18 horizontal rays. We optimized the color filter on the LCD to reproduce 60 rays. The resolution
of the display is 256x192, and the viewing angle is 30 degrees. These parameters are sufficient for mobile game
use. Users can interact with the IV display by using a control pad.
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.
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 manipulator's position on the volume data of MRI and could obtain the cross-section images of MRI at the manipulator's 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 manipulator's 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.