Daisuke Murayama

Arbitrary view generation for eye-contact communication using projective transformations

Eye-contact plays an important role for human communications in the sense that it can convey unspoken information. However, it is highly difficult to realize eye-contact in teleconferencing systems because of camera configurations. Conventional methods to overcome this difficulty mainly resorted to space-consuming optical devices such as half mirrors. In this paper, we propose an alternative algorithmic approach to achieve eye-contact by techniques of arbitrary view generation and projective transformations. Experimental results show that the synthesized arbitrary viewpoint images enable the eye-contact favorably.

Resource Transfer Channel Allocation Algorithm using Spectrum Suppression and Division Transmission in SATCOM Systems

To provide traffic channels to more earth stations with the limited bandwidth and power of a SATCOM system, this study proposes a novel channel allocation algorithm that partially transfers the bandwidth and power of existing traffic channels to a new traffic channel. To flexibly control transferred bandwidth and power and to effectively use dispersed unused bandwidth, the proposed algorithm is based on a spectrum suppression transmission technique and a spectrum division transmission technique. Simulation results show that the proposed algorithm as much as doubles the number of traffic channels in a SATCOM system compared with the conventional algorithm that fixes channel bandwidth and power during the communication period.

Virtual view image synthesis for eye-contact in TV conversation system

Eye-contact plays an important role for human communications in the sense that it can convey unspoken information. However, it is highly difficult to realize eye-contact in teleconferencing systems because of camera configurations. Conventional methods to overcome this difficulty mainly resorted to space-consuming optical devices such as half mirrors. In this paper, we propose an alternative approach to achieve eye-contact by techniques of arbitrary view image synthesis. In our method, multiple images captured by real cameras are converted to the virtual viewpoint (the center of the display) by homography, and evaluation of matching errors among these projected images provides the depth map and the virtual image. Furthermore, we also propose a simpler version of this method by using a single camera to save the computational costs, in which the only one real image is transformed to the virtual viewpoint based on the hypothesis that the subject is located at a predetermined distance. In this simple implementation, eye regions are separately generated by comparison with pre-captured frontal face images. Experimental results of both the methods show that the synthesized virtual images enable the eye-contact favorably.