In this paper, we present a six-band camera system and its application. This camera system was developed to recognize road environments on the basis of spectral information. The camera system has a commercial camera, a custom camera to capture three-band near infrared images and a custom mirror to reflect near infrared light. We present the architecture of a six-band camera system developed to measure reflectance characteristics on the basis of spectral information. We confirmed the effectiveness of our system by detecting the human skin both indoors and outdoors.
An ultra-high speed and very high sensitivity video camera is developed. The highest frame rate reaches 16,000,000 frames per second (16Mfps). The full well capacity is 22,000 e- at the frame rate up to 4 Mfps and 8,000 e- at the 16Mfps. The pixel count is 165 kpixels (362×456 = 165,072). The total number of consecutive frames is 117 and is doubled to 234 by the interlaced imaging operation. When the on-chip CCM (Charge Carrier Multiplier) is activated, signals of 7 e- can be detected.
We propose a visible light road-to-vehicle communication system at intersections as an ITS(Intelligent Transport System) technique. In this system, the communication between a vehicle and an LED traffic light is conducted using an LED traffic light as a transmitter and an on-vehicle high-speed camera as a receiver. The LEDs in the transmitter emit light at high frequency, and those emitted light is captured by the high-speed camera for communication. Here, the luminance value of the LEDs in the transmitter should be captured in consecutive frames to achieve communication. For this purpose, first the transmitter should be found, and then it should be tracked in consecutive frames while the vehicle is moving by processing the images from the high-speed camera. In this paper, we propose new algorithms for finding and tracking the transmitter, which result in increased communication speed and data rate compared to the previous methods. Experiments using appropriate images showed the effectiveness of the proposals.
We describe a color silicon retina system that has robust color detection regardless of changes in illumination color. The present model for color constancy is based on Land's retinex theory. In our model, an input image is divided into red, green, and blue channels, and received by silicon retinas that have a logarithmic response. In each channel, the received image is filtered with a Laplacian-Gaussian spatial filter. Opposite color responses, namely red-green and yellow-blue, are then calculated. We verified the color constancy of the proposed system with a simulation.
To realize a high-resolution two-dimensional integrated magnetic sensor, the process rule was changed from 0.35 to 0.18 μm. The fabricated magnetic sensor was an n-type Hall sensor that uses an inversion layer under the gate oxide of the MOSFET. The decided sensor area size was 6.6 × 6.6μm2. The Hall sensors were arrayed in 32 × 32 pixels. The average sensitivity of the fabricated magnetic sensors was 34.6mV/(mA·T), and this value was the same as that of fabricated magnetic sensors in the 0.35μm standard CMOS process. No degradation of sensitivity was introduced to a magnetic sensor fabricated in 0.18 μm process rule. From the result of two-dimensional integrated magnetic sensor, two-dimensional magnetic flux distribution was successfully measured from the 1-mm diameter Nd-Fe-B rare-earth permanent magnet. By changing the position of the probe that measures Hall voltage, the sensitivity of magnetic sensors was increased by 17%.
Performance of a polarization-analyzing CMOS image sensor was improved by two kinds of technical approach. Based on the whole-angle on-chip polarizer approach, a polarization-analyzing CMOS image sensor with multiple polarization-analyzing pixel array sets was designed Using 0.35μm standard CMOS technology. The accuracy of polarization analysis was improved to σ=0.0022 deg. A performance improvement of the on-chip polarizer was also demonstrated by a new photosensor designed with 65 nm standard CMOS technology.
We propose a method of virtual bokeh reconstruction by using only multiple differently-focused images acquired with a single system of lenses. First, we analyzed our previously proposed 3-D blurring filter that combines scene information and the acquired multiple differently-focused images to decompose the filter into ray-sets, each of which goes through a certain point on the lens. A new 2-D filter based on dimension reduction was then designed to allow the ray-sets to be reconstructed without the need to estimate the scene. A weighted composition of them provides free shapes of bokeh, i.e., the desired features of lenses and irises. Virtual bokeh reconstruction was simulated by utilizing synthetic multiple differently-focused images with a number of shapes of bokeh. The criteria for appropriate bokeh for image acquisition were also clarified. Finally, we show experimental results of virtual bokeh reconstruction from real images.
In Horn and Schunck (HS)'s optical flow method, a weighting parameter α of a motion smoothness constraint plays an important role in determining the estimation accuracy of optical flow. However, conventional methods to optimize the α have been based on an empirical selection or cross-validation, where a global optimization is done at a high computational cost. Thus, a more efficient optimization method is needed. We first assume that real images can be approximated by a two dimensional sinusoidal wave function based on an example of a previously used texture analysis. Two image features of amplitude (the standard deviation of image brightness) and wave number using the sinusoidal wave function are used to analyze and model the relationship between the optimal α and two image features. From the analyzed model, the optimal α can be used to locally minimize the estimation error of optical flow. Because the two simple image features of given real images are used, the optimal α can be efficiently estimated. Experimental results with the estimation accuracy of optical flow show that our proposed method outperforms conventional optical flow ones.
In this study, we discuss how to best use alumni networks for entrepreneurial and incubation processes of university spin-offs capitalizing on technology seeds. On the basis of previous studies, findings and theories, we hypothesized that alumni networks would be successful platforms through which mentors could support, advise, guide, and/or supervise entrepreneurs. To prove this claim, we conducted (1) a survey of incubation offices and alumni liaison offices in universities across Japan and (2) case studies of three advanced mentor organizations operated as alumni networks. The findings validated the hypothesis and further identified (1) the crucial characteristics of alumni networks for university spin-off development and (2) that a common premise and objective for the alumni network and the heterogeneity of its members, realized by including a certain percentage of alumni from other universities, is indispensable for a successful mentor platform.
There are two types of hologram, an amplitude modulation and a phase modulation ones. Recently, not only amplitude modulation ones but also phase modulation ones have been used in liquid crystal displays. We constructed an electro-holography system with a phase modulation type liquid crystal display and compared it to a system using current amplitude electro-holography. In the amplitude hologram, the reconstructed image darkens because the contrast of the hologram is low when the gray level is increased. It lightens most when binary. However, the phase hologram with high diffraction efficiency has produced an excellent result. The reconstructed image is bright even if the gray level is increased, and all the information of the liquid crystal display can be used at 256 gray levels.