Handwritten document processing apparatus and method

1. A handwritten document processing apparatus comprising:

an inputter that inputs stroke data;

a classifier that classifies the stroke data into data of a plurality of ruled lines and stroke data other than ruled lines;

a divider that divides a region including the plurality of ruled lines into first regions each corresponding to a cell bounded by four ruled lines and second regions each including at most three ruled lines; and

a determiner that determines whether a ruled line in the second region is a first ruled line, to one end point of which a ruled line is not connected, or a second ruled line, to one end point of which a virtual circumscribed ruled line is connected.

2. The apparatus of claim 1 , further comprising a first estimator that estimates the virtual circumscribed ruled line.

3. The apparatus of claim 1 , further comprising a second estimator that estimates straight-converted ruled lines of the plurality of ruled lines.

4. The apparatus of claim 2 , further comprising a display that displays the circumscribed ruled lines in a display mode different from that of the plurality of ruled lines of the stroke data.

5. The apparatus of claim 1 , wherein the determiner determines a ruled line which falls below a first reference value based on a statistical amount calculated from stroke lengths of ruled lines that defines the cell as the first ruled line.

6. The apparatus of claim 1 , wherein when one of the number of strokes and a total length of strokes other then the ruled lines in the second region is not less than a second reference value, the determiner determines that the ruled lines in the second region are the second ruled lines.

7. The apparatus of claim 1 , wherein based on a ratio of lengths of two line segments decided by an intersection point of two ruled lines in the second region, the determiner determines that a shorter line segment is the first ruled line.

8. The apparatus of claim 6 , wherein the determiner applies a determination result of the second ruled line using the second reference value to another second region which shares a ruled line, and determines that ruled lines in the other second region are the second ruled lines.

9. A handwritten document processing method comprising:

inputting stroke data;

classifying the stroke data into data of a plurality of ruled lines and stroke data other than ruled lines;

dividing a region including the plurality of ruled lines into first regions each corresponding to a cell bounded by four ruled lines and second regions each including at most three ruled lines; and

determining whether a ruled line in the second region is a first ruled line, to one end point of which a ruled line is not connected, or a second ruled line, to one end point of which a virtual circumscribed ruled line is connected.

10. A non-transitory recording medium that stores a program for controlling a computer to function as:

an inputter that inputs stroke data;

a classifier that classifies the stroke data into data of a plurality of ruled lines and stroke data other than ruled lines;

a divider that divides a region including the plurality of ruled lines into first regions each corresponding to a cell bounded by four ruled lines and second regions each including at most three ruled lines; and

a determiner that determines whether a ruled line in the second region is a first ruled line, to one end point of which a ruled line is not connected, or a second ruled line, to one end point of which a virtual circumscribed ruled line is connected.

11. A handwritten document processing apparatus comprising:

a processor configured to input stroke data, to classify the stroke data into data of a plurality of ruled lines and stroke data other than ruled lines, to divide a region including the plurality of ruled lines into first regions each corresponding to a cell bounded by four ruled lines and second regions each including at most three ruled lines, and to determine whether a ruled line in the second region is a first ruled line, to one end point of which a ruled line is not connected, or a second ruled line, to one end point of which a virtual circumscribed ruled line is connected; and

a memory connected to the processor.

12. A handwritten document processing apparatus comprising:

an inputter that inputs stroke data;

a classifier that classifies the stroke data into data of a plurality of ruled lines and stroke data other than ruled lines;

a divider that divides a region including the plurality of ruled lines into first regions each corresponding to a cell bounded by four ruled lines and second regions each including at most three ruled lines; and

a controller that controls a display to remove a small extension included in the second regions so that the small extension is not displayed.

13. A handwritten document processing apparatus comprising:

an inputter that inputs stroke data;

a classifier that classifies the stroke data into data of a plurality of ruled lines and stroke data other than ruled lines;

a divider that divides a region including the plurality of ruled lines into first regions each corresponding to a cell bounded by four ruled lines and second regions each including at most three ruled lines based on a number of intersections or a number of ruled lines;

and a display that displays a virtual circumscribed ruled line for the second regions.