PURPOSE: To accurately recognize a straight line with high accuracy, in a straight line recognition system in a full dot character pattern.

CONSTITUTION: This system is constituted so that by an outline point line extraction means 2, an outline points line is extracted from dot information in a character pattern 1, and by a vectorization means 3, respective points are linked by line segments from one bending point successively along the extracted outline points line, and when the direction of the line segment linking a present point and a former point coincides with the direction of the line segment linking the present point and a next point, a vector linking between the bending point and the next point is generated, and when the directions are different from each other, the next point is made a new bending point, and such an operation is repeated, and the vector showing the outline of the character pattern is generated, and by a temporary straight line extraction means 4, a horizontal or a vertical vector with prescribed number of dots or above is extracted as a temporary straight line, and by a straight line part recognition part 5, related to the extracted temporary straight line, the straight line is recognized based on the size and the direction of the vector connected to the front and rear of the temporary straight line.