Patent Number: 6,166,750

Title: Image processing apparatus and method for adding predetermined additional information to an image by adding a predetermined number of unit dots to partial color component data of the image

Abstract: Provided are an image processing method and apparatus in which there is little deterioration in picture quality when specific information specifying a copying machine or the user thereof is added to image data. Pixel data in an 8.times.4 array at a predetermined position of the image data is modulated by subtracting a predetermined value .alpha. from 2.times.4 pixel data 2302 and 2.times.4 pixel data 2303 and adding the predetermined value a to 4.times.4 pixel data 2301 in such a manner that the number of pixels from which the predetermined value is subtracted and the number of pixels to which the predetermined value is added will become equal. The modulated data serves as a unit of added information. A plurality of units of the added information are arranged on the image data and the added information is represented by the mutual positional relationship of the plurality of information units.

Inventors: Negishi; Akira (Fujisawa, JP)

Assignee: Canon Kabushiki Kaisha

International Classification: H04N 1/00 (20060101); B41J 002/415 (); G03G 013/04 ()

Expiration Date: 12/26/2017