A Study on Optimal Design of Hough Transform Algorithm for Real Time Vision

我们推进了对线段复合图形图形的实时提取机制的研究。我们利用霍夫变换作为基本特征提取方法。我们从直线提取的处理成本、复合图形图案与其特征的关系、实时性、对图像序列的适用性等方面进行了考察和评价，并明确了以下结果。为了实现实时处理，我们将霍夫变换应用于局部图像，而不是整个图像，并将各自的结果结合起来，从而减少了计算量。从空间分割次数与线段分辨率的关系以及计算代价的角度出发，构造了霍夫变换参数的最优设置过程。从特征提取机制的扩展角度出发，对特征提取算法进行了改进，使其更便于实际应用。作为线段提取的元机制，我们引入了模拟人类视觉搜索感兴趣点或区域的中心-精细/外围-粗糙模型，实现了全局特征提取机制。在此基础上，对数字线段的描述进行了研究，提出了一种新的表示方法和链式码描述算法。为了验证所提出的方法和算法在实时视觉中的有效性和适用性，我们将这些算法应用到一个自主足球机器人系统中，并在真实和实用的条件下进行了实验和评估。

We promoted our research to realize a real time mechanism to extract figure patterns compounded of line segments. We utilized the Hough transform as the basic feature extraction method. We examined and evaluated from the view points of the processing cost for straight line extraction, the relation between a compound figure pattern and its feature, real time processing, applicability to the image sequences, and we clarified the following results.In order to realize real time processing, we reduced the computation cost by applying the Hough transform not to the whole image but to the partial image and by combining the respective results. We constructed an optimal procedure for the setting of Hough transform parameters from the view point of the relation between the number of space division and the resolution of line segment and the computation cost. From the view point of the extension of the feature extraction mechanism, we improved the feature extraction algorithms for the practical use. As a meta-mechanism of line segment extraction, we introduced the center-fine/peripheral-coarse model which simulates the human vision to search the interesting point or area, and realized the global feature extraction mechanism. Furthermore, we investigated the description of digital line segment, and proposed a new representation method and an algorithm using chain code description. To confirm the effectivity and the applicability of the proposed methods and algorithms to real time vision, we implemented these algorithms to an autonomous robot system for soccer game and experimented, and evaluated under a real and practical condition.