Abstract: An image processing system includes: image capture apparatuses 10P and 10Q for capturing images of an object T; a light emitting apparatus 20 having a plurality of light emitting units L1 through L8 and a controller 21 for controlling on/off of the light emitting units L1 through L8; and an image processing apparatus 30 capable of performing image processing. The image processing apparatus 30 extracts feature points on the basis of an optical image formed on the object T by light emitted from the light emitting apparatus 20, correlates feature points on a plurality of images with each other, and calculates positions and orientations of the image capture apparatuses 10P and 10Q on the basis of the correlated feature points. With the image processing apparatus, image processing system and the image processing method using them, extraction of feature points from images and correlation of them can be easily performed.