JPS57185769A - Noise rejecting method - Google Patents

Abstract

PURPOSE:To obtain multi-vlue quantized picture with good picture quality withot noise between lines completely, by mask-processing a preprocessing picture multi-value-quantized for an input picture and making picture elements outside of character lines of the preprocessing picture ineffective(all white). CONSTITUTION:An input picture signal (a) obtained through the reading of a document original in a suitable sampling interval is applied to a preprocessing circuit 10, where the signal is multi-value-quantized at a suitable threshold value and stored in a storage circuit once. Next longitudianl and lateral scannings for the preprocessing picture stored at an inter-character line line pattern generating circuit 20 are made, picture element values (0-15) on picture element lines to each direction are accmulated and one dimensional projection pattern to each direction can be obtained. A binary pattern representing the character lines and inter-lines (space) of the input picture is formed to obtain a multi-value quantized picture (k') which makes picture elements at the outside of the character lines ineffective with a mask processing circuit 30 based on the pattern.