JPS5835674A - Extracting method for feature of online hand-written character - Google Patents

Abstract

PURPOSE:To recognize hand-written characters accurately, by calculating the sum of the shortest distances from the start point, the end point, and bend points of the polygonal line approximate pattern of a stroke to other strokes to detect a duplicate write stroke and extracting features for the duplicate write stroke. CONSTITUTION:One-character components of coordinate data are stored in a coordinate memory 1, and a flag bit is set in the last coordinates of strokes. Strokes of the memory 1 are approximated to polygonal lines by a polygonal approximating equipment 2, and coordinate values of their start points, end points, and bend points of polygonal lines are stored in a polygonal line register memory 3. A value of the shortest distance between coordinate values in the memory 1 and the first coordinates in the memory 3 is detected by a distance calculator 4 and is applied to an adder 5 and is added to contents of an addition value register 6, and the result is stored in the register 6. Contents of the register 6 are read out into a comparison discriminator 7; and when they are smaller than a certain value, the second stroke is discriminated as the duplicate write stroke of the first stroke, and thus, hand-written characters are recognized accurately.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a handwritten character feature extraction method for the purpose of recognizing handwritten characters drawn on a tablet.

Conventionally, in this type of feature extraction, the number of strokes of a character and various information about each stroke are extracted and used for character identification. You may have to trace some parts over again. In such a case, the number and order of strokes would be different from when they were normally written, resulting in a disadvantage that feature extraction would not be performed correctly. An object of the present invention is to detect double writing and use the information to solve the above-mentioned drawbacks, and will be described in detail below.

The attached drawing is a block diagram of an embodiment of the present invention, in which 1 is a coordinate memory, 2 is a polygonal line approximator, 3 is a polygonal line registration memory,
4 is a distance calculator, 5 is an adder, 6 is an addition value register, 7
is a comparison judge.

The coordinate data for one character is stored in the coordinate memory 1 in sample order, and the last coordinate of the stroke has a flag bit indicating the end of the stroke, which is set to 1.The polygonal line approximator 2 The polygonal line is approximated and the coordinate values of the starting point, end point, and dividing point of the polygonal line are stored in the polygonal line registration memory 3. Since the polygonal line approximation of the stroke is a widely known method, the explanation will be omitted here. .

Next, the distance calculator 4 detects the smallest distance between each coordinate value in the coordinate memory 1 corresponding to the first stroke and the first coordinate value in the polygonal line registration memory 3 regarding the second stroke, and calculates that value. The adder 5 adds the contents of the added value register 6 and stores the result in the added value register 6. Since the contents of the added value register 6 are initially cleared, the first detected value is stored as is in the added value register 6. Similarly, for the second coordinate value, the minimum value with respect to each coordinate value of the first stroke is detected and added to the addition value register 6. When the processing regarding the contents of the polygonal line registration memory 3 corresponding to the second stroke is completed in this way, the comparator 7 reads the contents of the added value register 6 and compares it with a certain value, and if it is smaller, the second stroke is It is determined that the first stroke is a double writing stroke, and 11" is written in the flag bit indicating that it is a double writing stroke in the data of the second stroke in the coordinate memory l. If it is not, " is written. Subsequently, the same process is performed for the contents of the coordinate memory 1 corresponding to the second stroke and the contents of the polygonal line registration memory 3 corresponding to the third stroke, and depending on the result, the flag bit indicating the second stroke of the third stroke is set to 11'' or Write 0". When the process is repeated in this way and the process is completed for the stroke before the last stroke of the character and the final stroke, the coordinate data of the stroke drawn by tracing over the previously drawn stroke again is stored in the coordinate memory 1. is in a state where the flag bit indicates that it is a double writing stroke.

As explained above, in this embodiment, even if the scribe draws once (tracing a part of the goni stroke again, etc.), that information is left on the coordinate data, so when extracting features, the stroke There is an advantage that normal feature extraction can be performed by using techniques such as ignoring information about information.

The present invention detects double writing strokes by calculating the sum of the shortest distances between the starting point, ending point, dividing point, and other strokes in the stroke polygonal approximation button. This method has the advantage of correctly extracting features even when there are double strokes, so it can be used for online handwritten character recognition such as numbers, alphabets, kana, and other symbols.

[Brief explanation of the drawing]

The accompanying drawings are block diagrams of embodiments of the invention. 1... Coordinate memory, 2... Polygonal line approximator, 3...
- Line registration memory, 4... distance calculator, 5... adder, 6... - addition value register, 7... comparison judger. Patent applicant Oki Electric Industry Co., Ltd. Patent application agent Megumi Yamamoto -! -1 glaze 4・A-1,awh snoring

Claims (1)

[Claims] When the coordinate data for one character is divided into strokes, and the distance between the start point, end, and side point of the polyline segment of each stroke's polygonal line approximation pattern and another stroke is smaller than a predetermined value, the polyline approximation pattern is An online handwritten character feature extraction method characterized in that the stroke is used for character identification, assuming that the stroke is a double writing stroke with respect to another stroke.