Image processing device capable of measuring characteristic of subject for photography

An image processing apparatus is provided to determine an exact end line of a pictured subject which is not elliptical. An image processing apparatus(200) is mounted to a machine vision based system to generate and output various information with regard to the size of a subject pictured. A video data binary-coding unit(210) binary-codes image data by a preset method. A subject detection unit(220) detects pixels(subject pixels) to make the subject by analyzing binary image data. An index information generating unit(230) classifies the subject pixels having connectivity among the extracted subject pixels and assigns identification information to each subject.