Mitsuharu Yamada

3D-measuring-modeling-system based on digital camera and PC to be applied to the wide area of industrial measurement

We have developed 3D-Measuring-Modelling System, which can be applied to any object from small to large size, using a note PC and digital cameras. This time, especially in view of its application to the area of industrial measurement, we have endeavored to attain higher accuracy in 3D measurement (from former 0.26mm to present below 0.1mm) as well as the further simplification of the measuring operation. For this purpose we have developed a scale bar and other peripheral devices and we assessed the resulted accuracy. Therefore, today we should like to report on the new system thus developed and its accuracy assessment, as well as its various application examples in automobile measurement.

Human Body Measurement by Digital Photogrammetry System

We have developed an automatic system of all around 3D measurement comprised of special digital cameras and projector in a unit, which can measure human body all around with high precision. It has a calibration box which we use, prior to photographing, to determine the exterior orientation parameters of the cameras so that 3D measurement can be performed automatically as soon as the photographing unit is set up against an object. For stereo-matching we created a robust matching system and integrated it into an all-automatic system.

Modeling stereo measurement error by considering camera vibration

Camera vibration in recorded video is a problem with both handheld and stationary devices that vibrate due to wind and other external forces. To facilitate the development of a robust stereo system that is immune to such camera vibration, this study aims to study establishes an error model for a stereo measurement system by considering camera vibration. In stereo measurements, we approximate the distribution of measurement error in images as a uniform distribution. Given this approximation, parameters of the distribution of measurement error are mean value μ and standard deviation σ, whereas amplitude A and frequency F are parameters of camera vibration. To verify the relationship between these parameters, we performed experiments using a vibration testing system. Results indicated that the vibration did not affect the mean value μ. We also found a positive correlation between standard deviation σ and amplitude A as well as a negative correlation between standard deviation σ and frequency F. Based on these findings, we estimate the parameters of measurement error by the camera vibration parameters and establish our proposed error model.