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An automatic computer analysis system for interferometric patterns is developed. A digital interferogram is stored on disk memory, and fringe skeletons of the interferogram are extracted, based on the two-dimensional gray level fringe peak detection method. Extracted fringe skeletons are thinned, and then their fringe orders are determined, during which process the fringe pattern is visually inspected. The least-square interpolation method is applied to determine the fractional fringe orders of pixels between fringe skeletons. All the procedures of analyzing fringe data, except for the fringe order determination, are automatically performed. A man-machine interactive method with a light pen is used to inform the determined fringe orders to the computer. A representative example of the fringe pattern analysis is presented.

Orientation and density of trabecular pattern observed in a bone is closely related to its mechanical properties and deseases of a bone are appeared as changes of orientation and/or density distrbution of its trabecular patterns. They have been treated from a qualitative point of view so far because quantitative analysis method has not be established. In this paper, the authors proposed and investigated some quantitative analysis methods of density and orientation of trabecular patterns observed in a bone. These methods can give an index for evaluating orientation of trabecular pattern quantitatively and have been applied to analyze trabecular pattern observed in a head of femur and their availabilities are confirmed. Key Words: Index of pattern orientation, Trabecular pattern, Pattern density, Quantitative analysis© (1982) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

3-D position determination is the most important function for robot systems in order to recognize an object and its circumstances. Semiconductor position sensitive device ( PSD ) is used widely for image position detection in 3-D position sensing systems. In order to increase the relative resolution of image position detection, a hybrid type position sensitive device (R-HPSD) has invented. Auxiliary output terminals are added between the output terminals of ordinary type PSD so that any continuous intervals between the selected output terminal pair can operates entirely the same as the ordinary type PSD. Relative resolution of image position detection for full sensing area can be incresed extremely without any serious sacrifice of the simplicity in implementation and high speed operation. Only the switching circuit for output terminal selection is required and the operation time becomes somewhat longer than twice of that in the ordinary type PSD. This makes us possible to extend new approarches for 3-D position dtermination in the field of robotics.

A new type of range sensing method adopting a mirror tunnel optics and based on the principle of triangulation have been developped. A mirror tunnel is placed between an observation lens and an object to be measured; a bright spot or a shadow grating is projected on to the object through the observation lens; the bright spot or the shadow grating is observed through the observation lens after reflection with the mirror tunnel; range information can be determined based on the principle of trianguration. The width of an optical system can be reduced to remarkably smaller than the effective base line of the triangulation, and it may be suitable to miniaturize a range sensing system such as an optical stylus, a proximity sensor, a miniaturized moire topography system and so on.

Optical position measuring methods can provide an effective tool for non-contact measurement of shape, deformation, movement and so forth. Many of them are based on the trianguration in the wide sense. In order to remove the correspondence problem in the triangulation, light beam projecting method has been used widely. In the light beam projecting method, surface of an object to be measured is swept by a bright spot and image positions of the bright spot are detected by the several mark position detecting apparatuses. Then the 3-D position of a bright spot is determined based on the principle of triangulation. In this method, the measuring accuracy of 3-D position is influenced considerably by the detecting accuracy of image position on the observation plane.

A high precision mark position sensing method for image position sensing detector (PSD) with kaleido scopic mirror tunnel (KM-PSM) is introduced. To increase the image position detecting precision of a sensor element itself, hybrid ( analogue and digital ) type position sensitive device (R-HPSD) is invented. In order to realize high precision and miniaturized 3-D position measuring system, 1-D mark direction sensing method (PM-DSM) which consist of a 1-D image position sensing element, a cylindrical lens and a parallel mirror tunnel is proposed. Furtheremore, an optical range sensing method (RORS) which is suitable to realize a miniaturized optical range sensing probe based on the triangulation, is proposed. In addition, an optical range sensing probe for advanced 3-D coordinates measuring machine is considered.

Transparency and volume perception are important issues in 3-D object perception. We report here a new visual effect in 3-D illusory object perception with binocular viewing, named `pantomime effect', and introduce a new framework of the effect based on three types of `sustaining cues'. We also compare sustaining cues with occlusion cues. In addition, the perception of transparent and volumetrical objects was verified by the experiments using another illusory probe stimulus. It was also found that side sustaining cues played an essential role in volume perception, and the transparency in pantomime effect was different from that in multilayer transparent planes depicted by a random dot stereogram.

A new type of moiré and its application to topography are discussed. moiré fringes are generated by observing a grating projected on an object under test with a scanning imaging device. The general equations of the projection-type moiré topography are given. By controlling the phase, the pitch, or the direction of the virtual grating corresponding to the scanning lines of the imaging device, the automatic sign determination of the contour lines is accomplished. By the use of a high precision flying spot scanner with CRT(DD-tube) and a minicomputer system, an experimental measurement system is developed. Very significant is the fact that a contour line system and a sectional shape of the object are automatically reconstructed and displayed on a color TV monitor.