Recently, we have reached to the era using many videos by various image display devices. In particular, since an opportunity of viewing a content in a large size display or a mobile device has been increased, it has become one of the important problems to prevent visually induced motion sickness (VIMS). Although various methods to cope this issue had been studied, most of them were not practical. For example, to employ biological signals as a signal analysis approach to detect VIMS is difficult to suppress a cost and to reduce weight in a general home TV or a mobile device with a biological signal measurement device. In employing global motion vectors, it is also difficult to shorten processing time of estimating motion information, because they are employed as an image processing approach. Therefore in this study, in order to decrease an adverse effect on a human body due to VIMS, the author focuses on screen shake (SS) as VIMS, and proposes a determination method of SS in consideration of high-speed processing. The histogram is calculated by using motion vectors which are obtained by a simple block matching method. After that, histograms of two types are employed as a motion analysis (MA). First type is a histogram of motion direction, and second type is a histogram of motion magnitude. In addition, a frequency analysis (FA) is performed in horizontal directions, i.e., right and left direction. Thereby, it is possible to extract a change point of motion information caused by SS. The proposed method (PM) finally uses the combination processing of MA of each histogram and FA to enhance accuracy. Generating pseudo swing images according to five kinds of shake type (stype), the simulation experiments are carried out to evaluate PM. As the results, the results of accuracy ratio are 1.000 in stype 1 and 2, it is greater than 0.714 in stype 3, and it is greater than 0.573 except for s2 sequence in stype 4. However, the results of 0.202–0.366 obtained in stype 5 are lower than in the other stypes, and consequently there is a problem in a slow pseudo swing. By the experimental results, it was revealed that the pseudo motions affected the values of the degree of similarity and PM could simply determine the state of SS. Next, the result of 5.53 × 10 ^-4 sec. per frame in PM was obtained as the evaluation result in the processing time. Hence, it was found that PM can realize a real-time processing. Moreover, it was revealed that PM is more practical than the conventional method, in which newly obtained motion vectors in spatial domain are used, since PM can use coded motion vectors. In the further study, an evaluation by using practical images, and an evaluation of the swing in vertical direction or 2D swing direction will be required.

A capturing system with multispectral filter array (MSFA) technology is proposed for shortening the capture time and reducing costs. Therein, a mosaicked image captured using an MSFA is demosaicked to reconstruct multispectral images (MSIs). Joint optimization of the spectral sensitivity of the MSFAs and demosaicking is considered, and pathology-specific multispectral imaging is proposed. This optimizes the MSFA and the demosaicking matrix by minimizing the reconstruction error between the training data of a hematoxylin and eosin-stained pathological tissue and a demosaicked MSI using a cost function. Initially, the spectral sensitivity of the filter array is set randomly and the mosaicked image is obtained from the training data. Subsequently, a reconstructed image is obtained using Wiener estimation. To minimize the reconstruction error, the spectral sensitivity of the filter array and the Wiener estimation matrix are optimized iteratively through an interior-point approach. The effectiveness of the proposed MSFA and demosaicking is demonstrated by comparing the recovered spectrum and RGB image with those obtained using a conventional method.

We propose a visual analysis approach for exploring the compositional process of composers in the Spectral School, with a particular focus on its sub-processes of sound analysis and synthesis. Spectral music has been one of the significant trends in contemporary music since the 1970s. Composers in the Spectral School use the acoustic properties of sounds as the basis of their compositional materials. One of the representative software systems they use is AudioSculpt, developed by IRCAM. We develop an accompanying system with AudioSculpt to manage the history of creating sounds with spectral analysis of sound materials. The salient feature of our system lies in its tessellated spectrogram space whose axes represent the elapsed time of the sound and the progress of composition. On the pixel-oriented, spatial substrate, the system makes it possible for users to analyze the compositional processes by using dedicated interactive manipulations. The present system can also be regarded as an initial attempt at managing the provenance of time-series events in the music visualization field. Our approach is intended to pave the way for composers and musicologists to analyze, develop, and share the compositional methodologies.

Lighting phenomena in participating media play important roles in many scenes. For its realistic rendering, it is necessary to simulate multiple light scattering in the media. This paper proposes an efficient and reasonably accurate method simulating multiply scattered light emitted from spot or beam light sources. This method utilizes the narrow beam theory, which analytically approximates multiple scattering phenomena for concentrated beam light sources. Although its naive straight-forward application does not allow satisfactory image synthesis, we successfully adopted the theory into a ray-marching scheme and obtained much improved results. Further, we discussed sampling issues to reduce aliasing artifacts and proposed an adaptive sampling scheme and an analytic filtering method. The method was successfully applied to shaft-of-light rendering.

When two different colors are switched at high speed, it becomes impossible for a human to distinguish them, and the color resulting from the mixing of two original colors can be perceived. If color mixing by switching is used to display an image on a liquid crystal display (LCD), the colors of the image perceived and the one captured from the LCD will be different. Thus, this display method can prevent illegal photography of images on the LCD. The objective of this study is to develop a method to display a desired color by switching two colors on an LCD. However, there are cases where flickering occurs. If the LCD can increase the switching speed, flickering will decrease. Furthermore, if flickering occurs even if the switching speed increases, it is necessary to clarify the range of brightness difference that can switch two colors without flickering. In this study, we examined whether flickering was observed using three types of switching speeds and combining nine types of grayscale images. The results show that flickering is reduced by a switching speed of 144 Hz, and combining two dark or light grayscales in the range of gradation level 127 or less makes it possible to switch without flickering. This result is useful in the design of two switching colors for displaying the desired colors.