Binary coding circuit

Abstract

Abstract PURPOSE:To convert the density of every partial picture from a specific number or raster scanning lines into a binary signal normally by obtaining a threshold value for the binary coding from a density distribution of plural picture elements constituting an picture in a circuit which codes the density of every picture element into a binary value. CONSTITUTION:A main scan on an original picture to be processed is made laterally to perform optical observation by a 0.1mm. pitch raster scan, and the density of every picture element arrayed in a plotting paper shape of 0.1mm. square is converted into multilevel one-byte data, which is stored in a picture memory 2. The picture in the memory 2 is scanned on raster basis by a Laplacian operator with 3X3 picture elements and a secondary differentiating circuit 3 obtains the secondary differential value of density variation of every picture element. A distribution of differential values is generated by a circuit 4, a selecting circuit 5 selects P percents of picture elements as scanning segments having higher differential values, and a circuit 6 generates a density distribution of the selected picture elements; and a circuit 7 determine the threshold value used for the binary coding by the density distribution, and the picture data is read by a reading circuit 8 out of the memory and compared with the threshold value from the circuit 7 to perform the binary coding.

Inventors

• 👤 Akira Inoue
• 👤 彰 井上
• 👤 Kiyoshi Iwata
• 👤 清 岩田
• 👤 Toshio Matsuura
• 👤 松浦　俊夫
• 👤 Katsuhiko Nishikawa
• 👤 克彦 西川

Bibliographic Details