Abstract
In the digital particle analysis by image processing, errors generate in the measurement of the perimeter in case a figure whose size is relatively small in the frame of the whole image. These errors are caused by the size and the orientation of the figure, and are unavoidable in some cases with the usual method. The new method, called the "Three Pixels Vector Method" has been developed. The above errors can be reduced remarkably by this new method. The principle and the ability of.this method, together with the other usual methods, are described in this report.
