4. The method of claim 3 , wherein the parameters are selected from a group consisting of: a height of the circumscribed rectangle starting from a baseline of the circumscribed rectangles; a height of the circumscribed rectangle; a width of the circumscribed rectangle; a distance of the circumscribed rectangle with respect to one of the circumscribed rectangles arranged adjacent to the circumscribed rectangle; and a number of black pixels contained in the circumscribed rectangle.
3. The method of claim 1 , wherein the converting step comprises the steps of: forming one or more circumscribed rectangles for each of the consecutive characters; and extracting one or more parameters from each of the circumscribed rectangles, the parameters being used as the layout information.