Today, the demand of services for comic contents increases because paper magazines and books are bulky while digital contents can be read anytime and anywhere with cellular phones and PDAs. To convert existing print comic materials into digital format such that they can be read using the cellular phones and the PDAs with small screens, it is necessary to divide each page into scene frames and to determine reading order of the scene frames. The division of comic images into the scene frames can be considered as a type of document layout analysis. We analyzed layout of comic images using density gradient. The method can be applied to comics in which comic balloons or pictures are drawn over scene frames. In this research, a method for detecting the scene frame division in comic images using the density gradient after filling the quadrangle regions in each image with black is proposed. Experimental results show that 80 percent of 672 pages in four print comic booklets are successfully d...