滴水算法

Among several contour splitting algorithms Dropfall algorithm is convenient and accurate for separating handwritten numerals. A set of Drop-fall algorithms can produce four possible cutting paths. Based on four Drop-fall algorithms, this paper deals with a pattern-oriented strategy for segmenting touching digits in order to solve the problem of determining which Drop-fall algorithm producing the best separation. In this strategy, background region of touching digits is analyzed by using water reservoirs concept at first, and then the classification scheme is developed to identify the pattern of touching digits according to the structural features extracted from the specified background region. To split touching digits, the pattern-oriented strategy is implemented by choosing one suitable Drop-fall algorithm applied to the pattern of current touching digits in terms of its performance characteristic. Experimental results show that the proposed strategy is effective for segmentation of handwritten touching digits. because the contour of an image is an information preserving descriptor of the image. Among several contour splitting algorithms Drop-fall algorithm [5] is convenient and effective, and the basis idea of the algorithm is to simulate a “drop-falling” process to generate a cutting path. Depending on different start point, movement rule and direction, a set of Dropfall algorithm consists of four Drop-fall algorithms which can lead to four possible cutting paths to divide touching digits. One of the four is likely to produce the right result and all of the possible cutting paths must be considered. Since no single algorithm is able to solve all possible situations, determining which algorithm producing the correct separation is a problem. In this paper, a touching pattern-oriented strategy for segmentation is proposed. In this strategy classification scheme of touching patterns is developed on the basis of analyzing structural features which are obtained from touching region of connected digits. According to the touching pattern, the suitable drop-fall method is chosen to perform the segmentation. The arrangement of the rest part of this paper is as follows. In Section 2 we first discuss the patterns of touching digits. Section 3 presents the overall segmentation procedure of Drop-fall algorithm. The pattern-oriented strategy is described in Section 4. Experiment is carried out and the result is reported in Section 5. Finally, a brief conclusion is drawn iSimple touching Two digits touch at a single location where there are two possible cases including: a. Single-segment touching They share a long continuous stroke segment (see Figure 1(a)). b. Single-point touching They are connected with a ligature and share one point. The ligature can either be a component of one of the digits or belong to no digit. The former has an end point of one stroke which touches one side of another stroke, or two end points of two strokes which touch each other. The latter is an extra component with two transition points connecting the digits and it should be removed before recognition. In terms of ligature circumstances, we define four sub-patterns inside single-point touching as below: 1) C_1: The ligature belongs to left digit (see Figure 1(b)). 2) C_2: The ligature belongs to right digit (see Figure 1(c)). 3) C_3: The ligature belongs to both left and right digits (see Figure 1(d)). 4) C_4: The ligature is yielded by consecutive writing between digits and belongs to no digit (see Figure 1(e)). 2. Multiple touching Two digits touch at multiple locations (see Figure 1(f)).
algorithm, Ascending-left algorithm, and Ascendingright algorithm (see Figure 2(a)-(b)). One of the four is likely to produce the right result.
2008 International Conference on Computational Intelligence and Security
A Touching Pattern-oriented Strategy for Handwritten Digits Segmentation
MA Rui 1 Zhao Yingnan 1 Xia Yongquan 2 Yan Yunyang 3 1 Computer and Software Institute, Nanjing University of Information Science & Technology, Nanjing 210044, China 2 Department of Computer and Communication Engineering, Zhengzhou University of Light Industry, Zhengzhou 450002,China. 3 Department of Computer Engineering, Huaiyin Institute of Technology, Huaiyin 223001, China E-mail: marui_mary@ Abstract
1. Introduction
Separating handwritten numeral strings has been a popular topic of research for many years, and it plays pivotal role in many numerous applications [1]. Separating touching digits is one of the main challenges in handwritten numeral segmentation. Generally numeral strings include isolated digits, touched, overlapped, and noisy or broken digits [2]. At present, many approaches have been proposed on segmentation of touching digits [3]. One major approach to handwritten digits segmentation is based on contour analysis [4]
2. Patterns of touching digits
While writing down digits, it is possible to have adjacent digits connected in several ways which include:
978-0-7695-3508-1/08 $25.00 © 2008 IEEE DOI 10.1109/CIS.2008.149