LETTER PITCH DETECTION SYSTEM

A method and apparatus for determining the pitch of a character of an aligned group of character images on the surface of a paper where the group contains several characters which touch or merge with each other. Blocks of separable letters are extracted from the aligned group of characters and the size and location of each is detected and stored. Based upon this information a permissible range for a one-letter block width is ascertained and the most frequently occurring letter block width in that permissible range is determined. Based on the most frequently occurring letter block width, an effective range or interval for determining letter pitch is ascertained and numerical method are employed to estimate the letter pitch.