Kohji Mitani

Real-Time Integral Imaging Based on Extremely High Resolution Video System

The authors discuss practical problems, focusing, and accuracy of lens arrays involved in constructing integral imaging systems. In general, it is recommended to set the focusing for the object during capture to infinity. The positional error of the elemental lens arrangement significantly affects the image quality when the image is reconstructed near the observer. An experimental system in consideration of the practical problems that uses an extremely high resolution video system is described. Some pictures obtained by the system show the specific characteristics of this spatial imaging type of system.

Ultrahigh-Definition Video System with 4000 Scanning Lines

An ultrahigh-definition video system is considered to be a prospective candidate for future broadcasting services providing a high sensation of reality. This paper will discuss the design considerations in the construction of an experimental ultrahigh-definition video system with 4000 scanning lines. The scanning parameters were determined based on the relationship between the sensation of reality and the viewing angle. The camera system was developed based on the four-CCD (charge-coupled device) image-acquisition technology: two 2.5-in. 8M-pixel CCDs are used for green, and one each for red and blue. The four-CCD beamsplitting system incorporates two-dimensional pixel offset to form a Bayer color-sampling pattern with the CCDs. A 4000-scanning-line display system was also developed. It is similar to the imaging system, which uses four 8M-pixel LCDs to realize a 4000-scanning-line system, one each for red and blue, and two for green with diagonal pixel offset. The viewing angle is more than 100° horizontally, at a standard viewing position of 3 m from a 320-in. (7 x 4 m) screen.

An 8k×4k Ultrahigh-Definition Color Video Camera with 8M-Pixel CMOS Imager

An ultrahigh-definition color video camera that uses new 1.25-in. 8M-pixel CMOS digital imagers and diagonal pixel shifting in a 4-pickup system has been developed. The camera head weighs less than 40 kg. A 5x zoom lens and a signal processing system incorporating a function for realtime lateral chromatic aberration correction was also developed. This function makes it possible to suppress optically generated color shifts across the entire zooming range. Moreover, opticalmultiplexing transmission equipment and a camera control unit were created. This camera has a limiting resolution of more than 3200 TV lines. The signal-to-noise ratio (SNR) on an HDTV video, which is extracted 1/16 from 8k x 4k pixels video for the reason of SNR measurement device, was about 45 dB. The sensitivity was 2000 lux at F2.8 with a dynamic range of 200%.

8K Extremely-High-Resolution Camera Systems

Research and development of ultrahigh-definition imaging systems that go beyond high-definition television (HDTV) have converged in the field of “4K” and “8K” imaging systems. The 4K imaging systems are used for digital cinema, while the 8K systems have been developed for use in next-generation TV broadcasting systems. The latter at 60 frames/s represents the highest pixel count and frame rate of any system, which includes their transmission design. In this paper, we will present an overview of two “8K” camera systems. One achieves a full resolution of 8K using three 33-Mpixel image sensors. The other is a more compact and practical camera system that uses four 8-Mpixel image sensors. We will also describe the camera functions, evaluation results, and views for future developments.

Experimental ultrahigh-definition color camera system with three 8M-pixel CCDs

An experimental ultrahigh-definition color camera system with twice the horizontal and vertical resolution of HDTV has been developed. It uses three 8M-pixel (4046 x 2048 active pixels) CCDs and performs progressive scanning at 60 frames/sec, so its data rate is eight times that of an HDTV signal. Eight parallel HD-SDIs are used as the output signal interface for data transmission, enabling the use of various types of HDTV equipment. This paper describes the goal of the study, the structure of the 8M-pixel CCD, and the specifications of the camera system.

Future prospects of HDTV : Technical trends toward 1080p

HDTV is flourishing in Japan and the U.S., and many other countries including those in Europe are planning to start their own services. Europe is now designing the route map to deploying HDTV. The recent progress in related technologies has accelerated the spread of HDTV throughout the world. In particular, the prospects for the picture format of 1080/50p, 60p are growing. This paper will try to give further insights on the prospects of HDTV. First, it will discuss the visual experience that HDTV gives the viewers in relation to his/her viewing environment. Then it will examine the trends toward 1080/50p, 60p from various perspectives, including flat panel displays, production equipment, coding technologies, HDTV television sets, higher resolution technologies beyond HD, and the trends of rival media.

Experimental color video capturing equipment with three 33-megapixel CMOS image sensors

We have been developing an ultra high definition television (UHDTV) system with a 7,680 horizontal by 4,320 vertical pixel resolution and a 60 Hz frame rate. This system, which is called Super Hi-vision (SHV), is expected to serve the next generation of broadcasting services. We have just completed the worlds first imaging equipment that is capable of capturing video at a full SHV resolution. In designing this equipment, we decided to develop three new devices, taking into account the camera performance and the ease of implementation. First, we developed a 33-megapixel CMOS image sensor. Its pixel size of 3.8 &mgr;m sq. retained the dynamic range of the sensor above 60 dB even with a 3-transistor pixel structure. Second, a fixed focal length lens was developed to create an adequate MTF right up to the limiting resolution of the sensor. Third, we developed a signal-processing device capable of handling 72 Gbps signals and cascading boards to expand the process. SHV images with a modulation of 20% at the Nyquist frequency were obtained by using these three key technologies.

Technical Development toward Implementation of Ultra High-Definition TV System

An extremely high-resolution image system called the Ultra High Definition TV (UHDTV) system, with more than 4000 scanning lines is being developed by the Japan Broadcasting Corp. (NHK). This system provides audio and video with an acute sense of reality so that viewers feel as if they are actually at the site of the filming. UHDTV cameras, projectors, disk recorders, and three-dimensional sound systems have already been developed. UHDTV programs were demonstrated at the 2005 World Exposition, Aichi, Japan, and the system worked successfully there during the six-month run. This paper presents two aspects of the newly developed UHDTV transmission systems: an optical transmission system with dense wavelength division multiplexing (DWDM) technology for contribution, and a codec system based on MPEG-2 for program distribution. A live transmission of uncompressed material with a 260-km single-mode fiber was also performed. For program distribution, some experiments were conducted at bit rates of 200 to 640 Mbits/sec via experimental satellite transponders or IP networks. These transmission experiments demonstrate the feasibility of using UHDTV in future broadcasting.

A Lateral Chromatic Aberration Correction System for Ultrahigh-definition Color Video Camera

We have developed color camera for an 8k x 4k-pixel ultrahigh-definition video system, which is called Super Hi- Vision, with a 5x zoom lens and a signal-processing system incorporating a function for real-time lateral chromatic aberration correction. The chromatic aberration of the lens degrades color image resolution. So in order to develop a compact zoom lens consistent with ultrahigh-resolution characteristics, we incorporated a real-time correction function in the signal-processing system. The signal-processing system has eight memory tables to store the correction data at eight focal length points on the blue and red channels. When the focal length data is inputted from the lens control units, the relevant correction data are interpolated from two of eights correction data tables. This system performs geometrical conversion on both channels using this correction data. This paper describes that the correction function can successfully reduce the lateral chromatic aberration, to an amount small enough to ensure the desired image resolution was achieved over the entire range of the lens in real time.

Four-chip CCD camera for HDTV

In an effort to realize a compact HDTV camera with high performance, we have developed a prototype equipped with four 2/3-inch CCDs. A smaller image format is preferable for downsizing TV cameras. However, this causes shrinkage of the unit pixel size and inevitably makes it more difficult to produce an image-pickup device with required HDTV qualities, especially sensitivity, and dynamic range. We have overcome this problem by using CCD imagers with high performance but with a relatively small number of pixels and by increasing the number of CCD chips used in a camera to secure the necessary spatial sampling points for HDTV. In the newly developed color-separating system of the camera, two of the four CCDs are assigned for the green (G) light component and one each for red (R) and blue (B). We succeeded in improving the resolution by introducing spatial pixel offset imaging. This new method has two major advantages: it prevents resolution degradation caused by chromatic aberration and improves the resolution of colored signals over a wide range.