PURPOSE: To make the image of a particle into binary and highly precisely conduct the center-of-gravity calculation without having no influence of brightness level by determining the binary level of the particle image in proportion to the maximum picture element value of a picture element.
CONSTITUTION: The particle of titanium oxide is mixed into a fluid in a vessel 2, and the scattered light or fluorescent light in a light surface 1A is photographed by a camera 3 from the direction orthogonal to a sheet and recorded in a picture recording device 4 by interlace system. Then, the recorded information is reproduced in the device 4, and picture-recorded in a frame memory 7 connected to a computer 6 so that the frame information has the same arrangement as the horizontal and vertical element numbers of the camera. The information recorded in the memory 7 is processed by the computer 6, the first time information is taken out, the memory information corresponding to the field information is left, and the information not corresponding to the field information is erased. The memory content corresponding to the information erased from the left information is interpolated. Then, the light density distribution is calculated from this information and made into binary at 1/4 of the maximum density, and the moment is calculated from this result to calculate the center of gravity of the particle.
NAMIENO TSUTOMU
MAZAWA MASATO
SAKANO YOICHI
IGUCHI MASAYA
MAEDA AKIHIRO
MITANI SHIYOUJI KK