This invention provides an image processing apparatus and method, which embed a digital watermark having strong robustness against geometrical transformation/edit processes such as rotation, scaling, translation, and the like, and an image processing apparatus and method, which can accurately extract the embedded digital watermark even after the conversion/edit process such as rotation of an image or the like. A Fourier transformer (901) converts an image input from an image input unit (900) into amplitude component data, and phase component data. An envelope ring pattern generator (902) generates an embedding pattern of digital watermark information, which is expressed by a set of lines that define a circle as an envelope, on the amplitude component data. An envelope ring pattern embedding unit (903) embeds digital watermark information at predetermined positions on the line. An inverse Fourier transformer (904) computes the inverse frequency transforms of the amplitude component data embedded with the digital watermark information using the phase component data.