JPS57185770A - Noise rejecting method - Google Patents

Abstract

PURPOSE:To obtain a binary picture in which noise between lines is completely rejected, by making mask-processing of preprocessed picture binarized an input picture and making pictures at the outside of character lines of the preprocessed picture ineffective (all white picture elements). CONSTITUTION:An input picture signal (a) obtained through the reading of a document original in suitable sampling density is applied to a preprocessing circuit 10, where the signal is binarized with a suitable threshold value and stored in a storage circuit once. Longitudinal and lateral scannings for the preprocessing picture stored at a character line/inter-line pattern generating circuit 20 are made, picture elements (0 or 1) on picture element lines to each direction are accumulated and a one dimensional projection pattern to each direction is obtained. A binary pattern representing the character lines and inter-lines (space) is formed from the projected pattern, and based on the pattern a binary picture in which black picture elements at the outside of the character lines are compulsively converted into white picture elements is obtained at a mask processing circuit 30.