Extraction of signature and seal imprint from bankchecks by using color information

The author proposes an extraction method for signatures and seal imprints using their color information for the automatic verification of Japanese bankchecks. The colors of the signature, the seal imprint, and the background pattern are generally different from each other. Accordingly the pixels of a color bank-check image consist of three clusters corresponding to signature, seal imprint and background in RGB 3D color space. The specific color region (i.e. the signature or seal imprint) can be extracted by projecting orthogonally all pixels of the bank-check image on to an appropriate axis in RGB color space, and by thresholding. An extraction program based on this method has been tested on about 40 images of real Japanese bankchecks with handwritten signatures and seal imprints. Experimental results show that this method can extract signatures and seal imprints separately and accurately