摘要放大率法测焦距实验是光学基础实验教学课程中一个非常重要的实验项目。传统的教学实验是利用人眼观察目镜珀罗板刻线像，再利用显微镜目镜分化板的叉丝对准珀罗板刻线进行测量。这样操作容易引起视觉疲劳，导致测量精度和效率低下。而光学CCD的发展和图像处理技术的应用使得测量焦距的数字化成为可能。应用到实验中可以具有很高的教学实用价值。43614

本课题采用数字CCD对经透镜成像的珀罗板刻线图像与显微镜目镜中的标尺图像进行采集，并采用数字图像处理技术对标尺刻线和珀罗板刻线进行提取，通过标尺刻线间距可以算出像素当量，通过珀罗板刻线间距可以计算出像高，从而最终计算出透镜焦距。提高了测量精度和效率。

关键词   焦距测量 放大率法 matlab  图像处理

毕业论文设计说明书外文摘要

Title  Digital transformation of the experiment of measuring   the focal length of lens by magnification method  

Abstract

Measuring focal length measurement by magnification method is an optical foundation experiment in teaching course and it is a very important experiment project. The traditional teaching experiment uses the human eye to observe the  line of Perot board in eyepiece,use the cross wire of the differentiation plate of microscope eyepiece to aligning Perot board line and measure it.It is easy to cause visual fatigue,and it leads to low measurement precision and efficiency.

And the application of the development of the optical CCD and image processing technology make it possible to measure the focal length of digital.It is of great value in practical teaching by applying it to the experiments.

This subject adopts digital CCD to acquire the images of the Perot board line and the scale in microscope eyepiece,and use the digital image processing technology to extract the scales and the Perot board line,we can calculate the pixel equivalent through the spacing of the scale line,and we can calculate the height of image through the spacing of the Perot line,thus finally we can calculate the focal length of lens.It improves the  precision and efficiency of the measurement.

Keywords  The focal length measurement  Magnification method  Matlab  The image processing

目   次

1  绪论 1

1.2  研究背景 1

1.2  透镜焦距测量方法概述 1

1.3  本文的工作内容 5

2  焦距仪数字改造的光路搭建 6

2.1  焦距仪结构 6

2.2  现有放大率法测透镜焦距的原理和步骤 7

2.3  图像采集系统的搭建 8

2.4  根据刻线图像测量透镜焦距的原理 10

3  图像处理算法设计 11

3.1  图像增强 12

3.2  二值化 14

3.3  膨胀 16

3.4  刻线中心提取 18

3.5  刻线拟合 26

3.6  焦距计算 27

结  论 28

致  谢 29

参考文献 30

1  绪论

1.1  研究背景