完整版数字图像处理作业题及部分答案

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 advantagesof a digital image? Let f(x,y) be an analog image, I(r, c) be a digital image, please giveexplanation 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 theeyes, 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D, D, D距E48离.(Given pixels p(3,4) and q(8,10), please calculate the following distance: D, D and D.) E486.什么是采样和量化？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 thevisual 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)Why(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？8.) 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givenDo histogram equalization on the 9.试给出以下直方图均衡化的步骤及结果 (Please) histogram 0.50.4 0.3 0.22 0.2 0.17 0.150.130.13 0.12 0.1 0.05 0.03 06 7 2 3 4 5 0 1 (a)Computation procedure:7 6 3 4 Grayscale 5 0 1 20.22 0.17 Original histgram 0.120.05 0.030.13 0.13 0.15Accumulated histgramGrayscale RoundMappingNew histgram10.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 a 3*3 spatial averaging filter to perform image smoothing; (2) using astandard 3*3 Laplacian operator to perform image sharpening; (3) perform 3*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 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;3.将这些灰度值从大到小排成列,找出排在中间位置的灰度值并将其赋给对应模板中心位置的象素;12.试简单叙述图像特征在空域与频域表示下的联系与区别。

(When image is represented in spatial and frequency domains respectively, what similarity or differences do they have? )13.分别画出低频增强滤波器, 高频增强滤波器转移函数曲线；(Please draw the transfer function curves for low-frequency filter and high-frequency filter respectively.)14.将高频增强和直方图均衡化结合起来使图像边缘锐化是一种常用的图像增强技术。

请问以上两个操作的先后顺序对增强效果有影响吗？为什么？(In order to sharpen the edge of animage, it is common to use high-frequency emphasis and histogram equalization together. Doesthe sequence of implementing two technologies have effect on results? Why?)15.同态滤波的理论基础和依据是什么？请给出实施步骤。

(What is the theory of homomorphic filtering? Please list the procedures to perform this filter)同态滤波的目的是压缩图像整体范围的同时，扩张用户所感兴趣的细节特征的灰度级范围；其理论基础和依据是假设光照模型为照度分量与反射分量的乘积，由于照度分量变化缓慢，对应于频域中高频成分，而反射分量对应于频域中低频成分，故可通过减弱低频和增强高频的滤波处理实现上述的目的；16.试简单叙述图像增强与图像复原技术之间的联系与区别。

(What are the relationship and difference between image enhancement and image restoration technology?)17.若成像系统为线性移不变系统，且仅受加性噪声n(x,y)干扰，即满足：g(x,y) = H[f(x,y)] + n(x,y), 请给出该系统下的图像退化模型并从冲激响应出发予以证明。

(Give a linear, position-invariant image system and only additional noise n(x,y) is considered,namely, g(x,y)=H[f(x,y)]+n(x,y), Please give the image degradation model and prove it bystarting with pulse response.)18.试给出估计图像退化函数的三种方式并简单叙述其基本思想。

(Please summary three principal ways to estimate the degradation functions in image restoration and descript its theoryin brief)19.逆滤波的基本原理是什么？试对其应用局限性及解决措施进行说明。

(What is the theory of Inverse Filtering? Please give comments on its application limitation and propose somesolutions)逆滤波本质上是在忽略噪声影响情况下对退化图像进行滤波，其滤波函数为原退化系统响应函数的倒数，故当原退化系统响应函数取值为零时存在计算上的困难，或当取值较小时，受噪声的影响大；解决措施：频率受限，仅对零频附件的区域进行处理20.如图所示，设影像空间变换过程中某像素被映射到失点的若A,B,C,DA,B,C,D内部点P(a,b),真影像像素, =66G=46, G=36, 分别为GG=76, 灰度值DACB试分别利用最近邻插值和双线性插值a=0.7,b=0.6,a figure, As shown in 方法计算点P的灰度值G. (P pixel P is mapped within one grid with four pixels. The=46, GG=76, =36, of four pixels are Ggray-levels CBA=66,and a=0.7,b=0.6. Please calculate thegray-levels G D interpolation; neighbor (1) nearest of pixel P by using)(2)bilinear interpolation.将一个补色和对应的光基色相混?3补色是什么3基色指的是哪三种基本颜色?对应的21.光的将一个补补色又是什么?基色指的是哪三种基本颜色?对应的3合产生何种颜色? 颜料的3补色之, 3补色与颜料的3基色3色和对应的颜料基色相混合产生何种颜色? 光的基色, 3Light? of are Secondary Colors of Which are Primary Colors Light? What 间有何种关系? (are Which of Light? Light of with its Secondary color What happen if we mix primary colorPrimary Colors of Pigments? What are Secondary Colors of Pigments? What happen if we mix)primary color of Pigments with its Secondary color of Pigments?colorand HSI give comments on RGB 试比较说明22.RGB颜色模型和HSI颜色模型. (Please models.)pseudo-coloris 什么是伪彩色图像处理？试给出伪彩色图像处理的两种常用方式。