Extraction of Text Region From Color Image Sequence of A Book Cover Containing Gilt Characters

抄録

We have proposed a system for extracting bibliography information from still color image of a book cover. Although it works efficiently for ordinary books, it seems impossible to obtain satisfying results with the exact same system for the book covers containing gilt characters. The reason is that while photographing a book cover onto the image plane, reflection effects on the book cover which contains gilt characters are much more complicated than that on ordinary ones, so that it is impossible to obtain a still image satisfied enough to be processed by the system. When photographing a book cover into a still image, for ordinary book covers there usually only is total diffuse reflection effects. While for those contain gilt characters, there is mixed reflection effects-diffuse reflection and mirror reflection. That mixed effects make some part of book cover invisible in the still image. Instead of a still image, image sequence photographed by a moving camera will be helpful. The reflection on one spatial point is changing because the effects of mirror reflection in different frames. That means that the intensity of the pixel corresponding to that spatial point could be bright enough to be visible in some frames and could be too dark to be visible in others. This paper describes an efficient method for extracting characters from color image sequence of book covers containing gilt characters, taking advantage of reflection changes in different frames to extract enough reflection information for proper character extraction. Integrated with this new method, the proposed system is expected to work more accurately.