PURPOSE:To generate a program which a machine can automatically process and which is encoded by separating the picture of the processing procedure of the program into a character area picture and a linear graphic area picture and recognition- processing them to combine recognition results. CONSTITUTION:A picture input device digital-inputs a flow chart where a character and a graphic are mixed and stores it in a picture memory 2. The picture stored in the memory 2 is separated into the character area image composed only by the character and the graphic area picture composed only by the graphic by a character/ graphic separation device 3. When an outline extraction part 43 takes AND between an original picture and a picture obtained by shifting the original picture to left by one picture element and takes AND between the picture of a processed result and the picture obtained by shifting the original picture to left by one picture element and takes AND of pictures obtained by shifting the original picture upward and downward by one picture element, a picture reduced in four directions by one picture element is formed, and an outline is extracted by taking exclusive OR between the picture and the original picture. A chain encoding part 44 raster-scans the picture whose outline is extracted in the extraction part 43 and a black picture element is substituted with a white picture element. When there is the black picture element, chain encoding is executed.