An image processing apparatus for performing predetermined processing on an image of a document having a character/line portion, a gradation portion and a background portion. The apparatus reads the document image, converts image densities to binary pixel data, and expands the black pixels in the vertical...http://www.google.fr/patents/US5583646?utm_source=gb-gplus-shareBrevet US5583646 - Apparatus for distinguishing image portions through image expansion
Apparatus for distinguishing image portions through image expansion
