Subject area extracting method and image pick up apparatus using the same

摘要

An image pickup apparatus comprises a space-frequency characteristic pattern irradiating section which irradiates a visible light which has passed through an optical filter having a predetermined space-frequency characteristic to the target object; a camera; a difference image generating section which generates a difference image between a first and a second image each picked up by the camera when the visible light is irradiated or not irradiated from the space-frequency characteristic pattern irradiating section; a space-frequency domain transforming section which transforms the generated difference image to a space-frequency domain to acquire a space-frequency characteristic of each pixel of the difference image; a space-frequency pattern collating section which collates the space-frequency characteristic of each acquired pixel with the space-frequency characteristic of the optical filter; and a subject image generating section which generates a subject image from which the subject area has been extracted based on a result of collation.