摘要：基于识别算法的可靠性和有效性,本篇论文选择道路交通标志中的限速标志作为研究对象。本篇论文做的工作和解决的问题包括：

(1)由于限速标志的周边环境因素的影响，比如天气，道路两旁树木枝桠、电线，横幅等的遮挡，都会造成获取的图片的色彩不理想、尺寸大小过小、图像不清晰、甚至是图像内容不完整。在这样的前提下，很有必要对获取的图片进行预处理。本文采用的预处理包括使图片的亮度增强；利用图像缩放技术调整图像尺寸；加快图像处理速度的图像裁剪等。

(2)根据道路限速标志独特的颜色特征，本文采用了基于RGB颜色空间的色彩分割，从而将背景和目标区域分离，生成图像。在RGB颜色空间中可以把肉眼观察到的目标区域显著的分割出来，而且花费的时间较少。63862

(3)根据限速标志独特的圆形特征，本文利用基于霍夫变化的圆检测算法提取出图像中的圆形目标区域。这个方法计算量相对小，实时性很好，可操作性较好，而且可靠性很高。在形状提取之后，利用投影法去除圆形轮廓。

(4)限速标志的识别是本文研究的内容中最重要的部分。本文采用的是模板匹配法，快速有效。

关键词  限速标志识别；颜色空间分割；圆形度；模版匹配

毕业设计说明书（论文）外文摘要

Title    Study On The Technique OfMotorway Speed Limit Sign Detecting And Recognition

Abstract In the paper，the research objects are located in speed limited signs，considering the reliability and validity．According to the results from the experiment research on algorithms， we can see that the algorithm is very valid，and amount of computation is very small．The main contents of the paper include：

1．It causes photo’s  colordistortion，photo’s size incongruity and photo’s fuzziness，due to environmental factors such as weather condition and traffic information and so on． In the paper， pretreatment is done to enhance the quality of the images， utilizing scaling techniques to adjust the size and utilizing restoration techniques to clear the fuzzy images．

2．Due to the color featheristics of the objects，the paper uses the threshold segmentation algorithm in RGB color space the object area and the background area will be separated into binary images．In RGB space，it makes objects separated from the background distinctly，and saves time． 

Through comparison analysis，the RGB color space segmentation is used，and isolated points al e eliminated by median filtering in the paper·

3．Because of the circle featheristics of the objects from the paper studying，the circle targets are extracted utilizing the circle algorith．The calculation of the circle is obtained by the size and perimeter of each region，which ale simple in principle，small in calculation，good real—time and good extracting effecs．After extracting the circle，the circle is eliminated through projection method，and the remains ale processed by mathematical morphology in order to fill the holes，eliminate the burrs on edge and make the object region smooth．

4．Recognition is the most important work in the paper． template matching is better．

Keywords ： speed limit signs recognition；color space segmentation；circle；template matching

第一章 绪论2

1.1研究的背景和意义2

1.2 限速标志识别的研究现状3

1.3 限速标志识别的难点4

1.4 本文主要工作4

第二章 算法总体流程6

2.1 基本流程6

2.2 图像预处理6

2.3 实验结果及比较7

第三章 限速标志检测11

3.1 概述11

3.2 算法流程11

3.3 实验结果及比较14