Discovering Good Regions for Teitelman's Character Recognition Scheme
Warren Teitelman presented a novel scheme for real time character recognition in his master's thesis submitted in June of 1963. A rectangle, in which a character is to be drawn, is divided into two parts, one shaded and the other unshaded. Using this division a computer converts characters into ternary vectors in the following way. If a pen enters the shaded region, a 1 is added to the vector. When the unshaded region is entered, a 0 is appended. Finally 1 illustrates the basic idea he used. Thus, with the shading shown, the character V is converted to 1 0 x 1 0.* A V drawn without lifting the pen would yield a 1 0 1. A t gives 1 0 w 1, and so on. Notice that each character may yield several vectors, depending upon the style of the user as well as the division of the rectangle into shaded and unshaded regions. In order to conserve storage space and reduce search time, the character vectors of Teitelman"s scheme are stored in a tree-like structure like that shown in figure 2.