The method of recognizing text, with a system having representative digital images stored in memory, comprising the steps:
- (a) building a library of library images of known entities comprising words, phrases and numbers using low frequency filtered Fourier coefficients, using many different font styles, and assembling them into font groups;
- the font groups being created by averaging Fourier coefficients of a particular entity in different font styles, with first and second properties generated for each coefficient, the first property being a mean value which equates to a unique location in Fourier space, the second property being a standard deviation associated with the averaging of the coefficients, this standard deviation being considered as a radius of a chosen font group, a font group center being a mean value derived by averaging Fourier coefficients of a particular entity in the different font styles;
- (b) inputting an image representing text;
- (c) digitizing the image to form a digital picture thereof;
- (d) storing the image in memory;
- (e) breaking the image into blocks of data, wherein the blocks represent entire words, phrases, or numbers;
- (f) placing a window around the first individual block;
- (g) performing a two-dimensional discrete Fourier Transform (2DDFT) of the image within the window;
- (h) adjusting the punctuations;
- (i) filtering both the real (cosine) and imaginary (sine) coefficients to the first N harmonics in both the vertical and horizontal axis, these coefficients then make up a total of M unique vectors which defines a M orthogonal vector space, wherein N is at least five and M is (2N+1).sup.2 ;
- (j) energy normalizing to unity the M unique vectors, which will eliminate the effects due to image brightness;
- (k) searching the library of known coefficients and finding the closest match by computing the smallest error between library image and input image;
- (l) calculating a confidence value of the closest match based on the radius of the chosen font group and the distance between the font group center and the input image;
- (m) storing the match if confidence is high, or further investigating if confidence is low.