PURPOSE: To simplify the editing process of a holograph information processor by applying the concept of ruled lines for expression of holographs to express the holographs in a line coordinate system related to the ruled lines and expressing the holograph data in the coordinate value of the line coordinate system even though a holograph covers plural lines.

CONSTITUTION: A tablet coordinate string (a) of the output of a tablet 11 of a coordinate reader 11 is transformed into a line coordinate string (b) of a line coordinate system by a line coordinate system transforming means 20. In this case, the rules lines are virtually and equidistantly arranged in a reading area of the tablet 11. Thus a holograph is expressed in a line coordinate system related to the rules lines. The line coordinate value (b) of the output of the means 20 is stored in a coordinate value string storing buffer 30, and the output (c) of the buffer 30 is displayed on a display means 60. On the other hand, the output (c) is transferred into a display coordinate value string (d) and displayed on an LCD 71. Meanwhile the output (c) received from the means 20 is inputted to an editing command recognizing means 41 and also to the string (a). The means 41 recognizes a command and inputs the recognized command to an editing means 50. The means 50 edits the contents of the buffer 30.