数字图像处理-作业题及部分答案解析

数字图像处理-作业题及部分答案解析

1.数字图像与连续图像相比具有哪些优点?连续图像f(x,y与数字图像I(c,r中各量的含义

是什么?它们有何联系和区别? (To be compared with an analog image, what are the advantages of a digital image? Let f(x,y be an analog image,I(r, c be a digital image, please give explanation and comparison for defined variables: f/I, x/r,and y/c

2.图像处理可分为哪三个阶段? 它们是如何划分的?各有什么特点?(We can divide "image

processing"into 3 stages,what are they? how they are divided?What are their features?

答:低级处理---低层操作,强调图像之间的变换,是一个从图像到图像的过程;

中级处理---

中层操作,主要对图像中感兴趣的目标进行检测和测量,从而建立对图像的描述,是一个从图像到数值或符号的过程;

高级处理---

高层操作,研究图像中各目标的性质和相互联系,得出对图像内容含义的理解以及对原来客观场景的解释;

3.试从结构和功能等角度分析人类视觉中最基本的几个要素是什么?什么是马赫带效应? 什

么是同时对比度?它们反映了什么共同问题? (According to the structure and function of the eyes,what are the basic elements in human vision? What is the Mach Band Effect? What is Simultaneous Contrast? What common facts can we infer from both Mach Band Effect and Simultaneous Contrast?

答:人的视觉系统趋向于过高或过低估计不同亮度区域边界的现象称为“马赫带”效应;同时对比度指的是人的视觉系统对某个区域感觉到的亮度除了依赖于它本身的强度,还与背景有关.

马赫带效应和同时对比度现象表明人所感觉到的亮度并不是强度的简单函数.

4.比较说明像素邻域、连接、通路以及连通基本概念的联系与区别。(Please compare the

following conceptions and their distinction:(1 neighborhood;(2 adjacency; (3 path;

(4 connectivity

5.设有某图像子集中p(3,4,q(8,10两像素点,试分别计算p和q之间的D4, D8, D E距

离.(Given pixels p(3,4and q(8,10, please calculate the following distance:D4, D8 and D E.

6.什么是采样和量化?什么是灰度分辨率与空间分辨率?它们如何影响图像视觉质量以及数

据量大小?(What are the definition of Sampling and Quantization?What are the definition of grayscale resolution and spatial resolution? How Sampling and Quantization process affect the visual quality and date volume of an image?

7.试举出常用的三种图像灰度映射规则并绘出相应的映射曲线。(Please give three common

gray-level mapping functions and their figure respectively

8.为什么一般情况下对离散图像的直方图均衡化并不能产生完全平坦的直方图?(Why

digital image with histogram equalization process cannot obtain fully flat histogram?

离散图像的灰度级数有限,只有当灰度级数趋近于无穷大时,直方图均衡化才能产生完全平坦的直方图

9. 试给出以下直方图均衡化的步骤及结果(Please Do histogram equalization on the given

histogram

10.

给定如下灰度图像,根据下列要求给出对正方形区域内四个象素进行空间滤波增强的结果:

①:设计一个大小为3x3的空间均值滤波器进行图像平滑;②:利用3x3的标准拉普拉斯算子进行图像锐化;③:以3x3的模板进行图像中值滤波;(Please filter pixels marked with rectangle:(1 using a3*3spatial averaging filter to perform image smoothing;(2using a standard 3*3 Laplacian operator to perform image sharpening;(3 perform3*3 median filtering

11. 与均值平滑滤波器相比,中值滤波器有何优点?

请给出中值滤波实施步骤。(What advantages

does median filter have, compared with averaging filter? Please list necessary procedures how to

0.5 0.4 0.3 0.1 0

0.2 (a

perform a median filter

与均值平滑滤波器相比,中值滤波器能在消除噪声的同时保留图象的细节,其实施步骤为:

1.将模板在图中漫游,并将模板中心与图中某个象素位置重合;

2.读取模板下各对应象素的位置灰度值;