When taking a photo of impressive scene, we sometimes feel significant discrepancy between the scene we perceived and that captured by the camera. One of the factors that cause this problem lies in the difference between the characteristic of human visual perception and that of the camera’s projection model. Human beings perceive scenes by enlarging an area of interest (AOI), whereas an ordinal camera captures the entire scene evenly. In addition, it is known that accurate size perception is more difficult in virtual scenes than in real scenes, thus it is not easy to share subjective impressions obtained in the virtual space effectively with others. In this paper, therefore, we propose Digitus View Finder (DVF), a system that automatically outputs images close to the scene the user perceives. The user is allowed to operate this system immersively, intuitively, and accurately using a gesture interface to identify their own AOI. The suggestive interface progressively improves the accuracy of scale factor by learning individual differences practically. The effectiveness of the DVF system was confirmed empirically through a user study.

For the maintenance and inspection of components, three-dimensional objects that have already been assembled often need to be disassembled and reassembled. When an assembled product has been disassembled and reassembled, the assembly drawing that generally accompanies the product is assisted to assemble. However, since assembly drawings are two-dimensional representations of information, they may not be able to depict all the detailed features of the components, and may have limitations in terms of what they can display. Furthermore, if the assembly drawing is lost or never existed in the first place, reproducing the assembly procedure can be difficult. Therefore, in this paper, we propose a method to assist the reassembly of components by recording and reproducing the order of disassembly. This method involves recording the disassembly procedure each time a component is disassembled, reproducing the assembly procedure by following the recorded order during reassembly, and presenting the procedure to the user.

An ordinary 3D object, when reflected in a mirror, reverses its orientation along the line perpendicular to the mirror surface. However, some objects defy this expectation due to an optical illusion. This paper concentrates on one such visual phenomenon, in which a 3D object looks like it is translated in a mirror reflection, instead of having a reversed orientation. We name this phenomenon the “translation illusion.”We consider mathematical conditions for this illusion, propose an algorithm for designing this class of 3D objects, show various examples, and discuss possible extensions for providing a new technique to create 3D artwork.