数字图像处理 综合作业2
图形图像处理大作业2
期末大作业报告课程名称:数字图像处理设计题目:手写数字识别学院:信息工程与自动化学院专业:计算机科学与技术年级: 2012 学生姓名:和云山(学号 201210405106)指导教师:王剑日期: 2015.6.19教务处制摘要随着信息技术的发展,信息建设在我国取得了迅猛的发展,数字识别技术的应用需求越来越广泛。
数字识别一般通过特征匹配及特征判别的方法来进行处理,前者一般适用于规范化的印刷体字符识别,现今该技术基本成熟;后者多用于手写字符识别,其研究还处于探索阶段,识别率还比较低。
因此,本文主要阐述手写数字识别技术。
人工神经网络技术在今年取得了巨大的发展,它具有的高度非线性,使我们能表达一些至少是目前尚无法用计算理论表达清楚的外部世界模型;同时,神经网络所具有的自学习,自组织能力使我们能在与外部世界的交互作用下,实现无法用当前的计算理论表达清楚的功能;对于那些无法建立精确数学模型的系统,神经网络有着独特的优势。
本文基于BP神经网络的方法来实现手写体数字识别。
首先对图像进行灰度化、二值化、平滑去噪、归一化、细化的预处理。
然后采用逐像素特征提取法提取数字图像特征。
最后是BP神经网络分类器的建立和识别过程,对训练后的网络模型进行测试,得出训练样本的识别率为98%,测试样本达到78%的识别率。
关键词:数字识别;预处理;BP神经网络一、实验原理手写体数字识别常规预处理和特征提取方法1.1 手写体数字识别的识别过程手写体数字识别时,使用不同的方法,处理的步骤可能并不完全相同。
但是就一般情况看,一个完整的识别系统,在识别时大致要经过以下几个处理阶段,如图3-1所示。
图1-1 识别过程图 1.2 手写体数字识别的常规预处理方法神经网络为手写体数字识别提供了一个强有力的手段。
目前,在神经网络模式识别中根据对输人样本的表达方式的选择有下面两大类:一类是直接将数字图像经数值化处理之后得到的像素点原始样本作为神经网络的输入;另一类则是对这种原始像素点构成的原始输人样本再作进一步的预处理或变换。
《数字图像处理》期末大作业
《数字图像处理》期末大作业大作业题目及要求:一、题目:本门课程的考核以作品形式进行。
作品必须用Matlab完成。
并提交相关文档。
二、作品要求:1、用Matlab设计实现图形化界面,调用后台函数完成设计,函数可以调用Matlab工具箱中的函数,也可以自己编写函数。
设计完成后,点击GUI 图形界面上的菜单或者按钮,进行必要的交互式操作后,最终能显示运行结果。
2、要求实现以下功能:每个功能的演示窗口标题必须体现完成该功能的小组成员的学号(后三位)。
1)对于打开的图像可以显示其灰度直方图,实现直方图均衡化和直方图匹配(规定化)。
2)实现灰度图像的对比度增强,要求实现线性变换和非线性变换(包括对数变换和指数变换)。
3)实现图像的缩放变换、旋转变换等。
4)图像加噪(用输入参数控制不同噪声),然后使用空域和频域进行滤波处理。
5)采用robert算子,prewitt算子,sobel算子,拉普拉斯算子对图像进行边缘提取。
6)读入两幅图像,一幅为背景图像,一幅为含有目标的图像,应用所学的知识提取出目标。
3、认真完成期末大作业报告的撰写,对各个算法的原理和实验结果务必进行仔细分析讨论。
报告采用A4纸打印并装订成册。
附录:报告模板《数字图像处理》期末大作业班级:小组编号:组长:小组成员:浙江万里学院计算机与信息学院2013年12月目录(自动生成)1 绘制灰度直方图,实现直方图均衡化和直方图匹配(规定化)1.1 算法原理1.2 算法设计1.3 实验结果及对比分析图1 ××××××图2 ××××××分析***********************************************2 灰度图像的对比度增强2.1 算法原理2.2 算法设计2.3 实验结果及分析3 图形的几何变换3.1 算法原理3.2 算法设计3.3 实验结果及分析4 图像加噪(用输入参数控制不同噪声),然后使用空域和频域进行滤波处理4.1 算法原理4.2 算法设计4.3 实验结果及分析5 采用robert,prewitt,sobel,拉普拉斯算子对图像进行边缘提取5.1 算法原理5.2 算法设计5.3 实验结果及分析6 读入两幅图像,一幅为背景图像,一幅为含有目标的图像,应用所学的知识提取出目标6.1 算法原理6.2 算法设计6.3 实验结果及分析7 小结(感受和体会)(英文版)Two regulations promulgated for implementation is in the party in power for a long time and the rule of law conditions, the implementation of comprehensive strictly strategic plan, implementation in accordance with the rules and discipline to manage the party, strengthen inner-party supervision of major initiatives. The two regulations supporting each other, the < code > adhere to a positive advocate, focusing on morality is of Party members and Party leading cadres can see, enough to get a high standard; < rule > around the party discipline, disciplinary ruler requirements, listed as "negative list, focusing on vertical gauge, draw the party organizations and Party members do not touch the" bottom line ". Here, the main from four square face two party rules of interpretation: the first part introduces two party Revised regulations the necessity and the revision process; the second part is the interpretation of the two fundamental principles of the revision of laws and regulations in the party; the third part introduces two party regulations modified the main changes and needs to grasp several key problems; the fourth part on how to grasp the implementation of the two regulations of the party. < code > and < Regulations > revised the necessity and revised history of the CPC Central Committee the amendment to the Chinese Communist Party members and leading cadres honest politics several guidelines > and < Chinese Communist Party discipline and Punishment Regulations > column 1 by 2015 to strengthenparty laws and regulations focus. Two party regulations revision work lasted a Y ears, pooling the wisdom of the whole party, ideological consensus, draw historical experience, respect for the wisdom of our predecessors, which reflects the unity of inheritance and innovation; follow the correct direction, grasp the limited goals, adhere to the party's leadership, to solve the masses of the people reflect a focus on the problem. The new revision of the < code > and < rule >, reflects the party's 18 and the eighth session of the third, the spirit of the fourth plenary session, reflecting the experience of studying and implementing the General Secretary Xi Jinping series of important speech, reflects the party's eighteen years comprehensive strictly practice. (a) revised two regulations of the party need of < the ICAC guidelines > in < in 1997 Leaders as members of the Communist Party of China clean politics certain criteria (Trial) > based on revised, the promulgation and implementation of January 2010, to strengthen the construction of the contingent of leading cadres play an important role. But with the party to manage the party strictly administering the deepening, has not been able to fully meet the actual needs. Content is too complicated, "eight prohibition, 52 are not allowed to" hard to remember, and also difficult to put into practice; the second is concisely positive advocated by the lack of prohibited provisions excessive, no autonomy requirements; the third is banned terms and discipline law, both with the party discipline, disciplinary regulationsrepeat and Criminal law and other laws and regulations repeat; the fourth is to "clean" the theme is not prominent, not for the existing problems, and is narrow, only needle of county-level leading cadres above. < rule > is in 1997 < Chinese Communist Party disciplinary cases (Trial) > based on revision, in December 2003 the promulgation and implementation, to strengthen the construction of the party play very important role. Along with the development of the situation, which many provisions have been unable to fully meet the comprehensive strictly administering the practice needs. One is Ji law, more than half of the provisions and criminal law and other countries laws and regulations Repetition; two is the political discipline regulations is not prominent, not specific, for violation of the party constitution, damage the authority of Party Constitution of misconduct lack necessary and serious responsibility to pursue; third is the main discipline for the leading cadres, does not cover all Party members. Based on the above situation, need to < the criterion of a clean and honest administration > and < rule > the two is likely to be more relevant regulations first amendment. By revising, really put the authority of Party discipline, the seriousness in the party tree and call up the majority of Party members and cadres of the party constitution of party compasses party consciousness. (II) two party regulations revision process the Central Committee of the Communist Party of China attaches great importance to two regulations revision . Xi Jinping, general books recorded in the FifthPlenary Session of the eighth session of the Central Commission for Discipline Inspection, on the revised regulations < > made clear instructions. According to the central deployment, the Central Commission for Discipline Inspection from 2014 under six months begin study two regulations revision. The Standing Committee of the Central Commission for Discipline Inspection 4 review revised. Comrade Wang Qishan 14 times held a special meeting to study two regulations revision, amendment clarifies the direction, major issues of principle, path and target, respectively held a forum will listen to part of the province (area) secretary of the Party committee, Secretary of the Discipline Inspection Commission, part of the central ministries and state organs DepartmentThe first party committee is mainly responsible for people, views of experts and scholars and grassroots party organizations and Party members. Approved by the Central Committee of the Communist Party of China, on 7 September 2015, the general office of the Central Committee of the Party issued a notice to solicit the provinces (autonomous regions, municipalities) Party, the central ministries and commissions, state ministries and commissions of the Party (party), the General Political Department of the military, every 3 people organization of Party of two regulations revision opinion. Central Commission for Discipline Inspection of extensive solicitation of opinions, careful study, attracting, formed a revised sent reviewers. In October 8 and October 12, Central Committee PoliticalBureau Standing Committee and the Political Bureau of the Central Committee After consideration of the two regulations revised draft. On October 18, the Central Committee of the Communist Party of China formally issued two regulations. Can say, two laws amendment concentrated the wisdom of the whole party, embodies the party. Second, < code > and < Regulations > revision of the basic principles of two party regulations revision work and implement the party's eighteen, ten eight plenary, the spirit of the Fourth Plenary Session of the Eleventh Central Committee and General Secretary Xi Jinping important instructions on the revised < low political criterion > and < Regulations >, highlighting the ruling party characteristics, serious discipline, the discipline quite in front of the law, based on the current, a long-term, advance as a whole, with Bu Xiuding independent < rule > and < rule >. Main principle is: first, adhere to the party constitution to follow. The constitution about discipline and self-discipline required specific, awaken the party constitution of party compasses party consciousness, maintaining the authority of the constitution. General Secretary Xi Jinping pointed out that "no rules, no side round. Party constitution is the fundamental law, the party must follow the general rules. In early 2015 held the eighth session of the Central Commission for Discipline Inspection Fifth Plenary Session of the 16th Central Committee, Xi Jinping again pointed out that constitution is the party must follow the general rules, but also the general rules." the revisionof the < code > and < rule > is Method in adhere to the regulations established for the purpose of combining rule of virtue is to adhere to the party constitution as a fundamental to follow, the constitution authority set up, wake up the party constitution and party rules the sense of discipline, the party constitution about discipline and self-discipline specific requirements. 4 second is to adhere to in accordance with the regulations governing the party and the party. The Party of rule of virtue "de", mainly refers to the party's ideals and beliefs, excellent traditional style. The revised the < code > closely linked to the "self-discipline", insisting on the positive initiative, for all members, highlight the "vital few", emphasized self-discipline, focusing on the morality, and the majority of Party members and the ideological and moral standards. The revised < > Ji method separately, Ji, Ji Y an to Method, as a "negative list", emphasizing the heteronomy, focusing on vertical gauge. Is this one high and one low, a positive reaction, the strict party discipline and practice results transformation for the integration of the whole party to observe moral and discipline requirements, for the majority of Party members and cadres provides benchmarking and ruler. Third, insist on to. In view of the problems existing in the party at the present stage, the main problems of Party members and cadres in the aspect of self-discipline and abide by the discipline to make clearly defined, especially the party's eighteen years strict political discipline and political rules, organization and discipline andto implement the central eight provisions of the spirit against the four winds and other requirements into Disciplinary provisions. Not one pace reachs the designated position, focusing on in line with reality, pragmatic and effective. After the revision of major changes, major changes in the < code > and < rule > modified and needs to grasp several key problems (a) < code > < code > adhere to according to regulations governing the party and party with morals in combination, for at the present stage, the leadership of the party members and cadres and Party members in existing main problems of self-discipline, put forward principles, requirements and specifications, showing Communists noble moral pursuit, reflected at all times and in all over the world ethics from high from low 5 common requirements. One is closely linked to the "self-discipline", removal and no direct relation to the provisions of . the second is adhere to a positive advocate, "eight prohibition" 52 are not allowed to "about the content of the" negative list moved into synchronization amendment < cases >. Three is for all the party members, will apply object from the leadership of the party members and cadres to expand to all Party members, fully embodies the comprehensive strictly required. The fourth is prominent key minority, seize the leadership of the party members and cadres is the key, and put forward higher requirements than the ordinary Party members. Five is to simplify, and strive to achieve concise, easy to understand, easy to remember. The revised < code > is the ruling Party since the first insists ona positive advocate forAll Party members and the self-discipline norms, moral declaration issued to all members of the party and the National People's solemn commitment. > < criterion of a clean and honest administration consists of 4 parts, 18, more than 3600 words. After the revision of the < code >, a total of eight, 281 words, including lead, specification and Party member cadre clean fingered self-discipline norms, etc. Part 3 members low-cost clean and self-discipline, the main contents can be summarized as "four must" "eight code". Lead part, reiterated on ideal and faith, fundamental purpose, the fine traditions and work style, noble sentiments, such as "four must" the principle of requirements, strong tone of self-discipline, The higher request for 6 and supervised tenet, the foothold in permanent Bao the party's advanced nature and purity, to reflect the revised standards requirements. Members of self-discipline norms around the party members how to correctly treat and deal with the "public and private", "cheap and rot" thrifty and extravagance "bitter music", put forward the "four norms". Party leader cadre clean fingered self-discipline norms for the leadership of the party members and cadres of the "vital few", around the "clean politics", from civil servant of the color, the exercise of power, moral integrity, a good family tradition and other aspects of the leadership of the party members and cadres of the "four norms" < > < norm norm. "The Party member's self-discipline norms" and "party members and leading cadre clean fingered self-discipline norms," atotal of eight, collectively referred to as the "eight". "Four must" and "eight" of the content from the party constitution and Party's several generation of leaders, especially Xi Jinping, general secretary of the important discussion, refer to the "three discipline and eight points for attention" statements, and reference some embody the Chinese nation excellent traditional culture essence of epigrams. (2) the revised regulations, the main changes in the revised Regulations > to fully adapt to the strictly requirements, reflects the according to the regulations governing the law of recognition of deepening, the realization of the discipline construction and Jin Ju. < rule > is party a ruler, members of the basic line and follow. And the majority of Party members and cadres of Party organizations at all levels should adhere to the bottom line of thinking, fear discipline, hold the bottom line, as a preventive measure, to keep the party's advanced nature and purity. 1, respect for the constitution, refinement and discipline. Revised < rule > from comprehensive comb physical constitution began, the party constitution and other regulations of the Party of Party organizations and Party discipline requirements refinement, clearly defined in violation of the party constitution will be in accordance with regulations to give the corresponding disciplinary action. The original 10 categories of misconduct, integration specification for political discipline, discipline, honesty and discipline masses Ji Law and discipline and discipline and other six categories, the content of < rule >real return to Party discipline, for the majority of Party members and listed a "negative list. 7 2, highlighting the political discipline and political rules. > < Regulations according to the stage of the discipline of outstanding performance, emphasizing political discipline and political rules, organization and discipline, in opposition to the party's leadership and the party's basic theory, basic line, basic program and basic experience, the basic requirement of behavior made prescribed punishment, increase the cliques, against the organization such as violation of the provisions, to ensure that the central government decrees and the Party of centralized and unified. 3, adhere to strict discipline in the law and discipline In front, Ji separated. Revised < Regulations > adhere to the problem oriented, do Ji separated. Any national law existing content, will not repeat the provisions, the total removal of 79 and criminal law, repeat the content of the public security management punishment law, and other laws and regulations. In the general reiterated that party organizations and Party members must conscientiously accept the party's discipline, die van comply with national laws and regulations; at the same time, to investigate violations of Party members and even criminal behavior of Party discipline and responsibility, > < Regulations distinguish five different conditions, with special provisions were made provisions, so as to realize the connection of Party discipline and state law. 4, reflect Wind building and anti-corruption struggle of the latest achievements. < rule > the party's eighteen yearsimplement the spirit of the central provisions of the eight, against the requirements of the "four winds" and transformation for disciplinary provisions, reflecting the style construction is always on the road, not a gust of wind. In the fight against corruption out of new problems, increase the trading rights, the use of authority relatives profit and other disciplinary terms. Prominent discipline of the masses, the new against the interests of the masses and ignore the demands of the masses and other disciplinary terms and make provisions of the disposition and the destruction of the party's close ties with the masses.Discipline to protect the party's purpose. 8 of these regulations, a total of three series, Chapter 15, 178, more than 24000 words, after the revision of the regulations a total of 3 series, Chapter 11, 133, 17000 words, divided into "general" and "special provisions" and "Supplementary Provisions" Part 3. Among them, add, delete, modify the provisions of the proportion of up to nearly 90%. 1, the general general is divided into five chapters. The first chapter to the regulations of the guiding ideology, principles and scope of application of the provisions, highlight the strengthening of the party constitution consciousness, maintenance the authority of Party Constitution, increase the party organizations and Party members must abide by the party constitution, Y an Centralized centralized, would examine at all levels of the amended provisions implementing and maintaining Party discipline, and consciously accept the party discipline,exemplary compliance with national laws and regulations. The second chapter of discipline concept, disciplinary action types and effects of the regulations, will be a serious warning from the original a year for a year and a half; increase the Party Congress representative, by leaving the party above (including leave probation) punishment, the party organization should be terminated its representative qualification provisions. The third chapter of the disciplinary rules of use prescribed in the discipline rectifying process, non convergence, not close hand classified as severely or heavier punishment. "Discipline straighten "At least eighteen years of five years, these five years is to pay close attention to the provisions of the central eight implementation and anti -" four winds ". The fourth chapter on suspicion of illegal party disciplinary distinguish five different conditions, with special provisions were made provisions, to achieve effective convergence of Party and country 9 method. < rule > the provisions of Article 27, Party organizations in the disciplinary review found that party members have committed embezzlement, bribery, dereliction of duty dereliction of duty and other criminal law act is suspected of committing a crime shall give cancel party posts, probation or expelled from the party. The second is < Regulations > Article 28 the provisions of Party organizations in the disciplinary review But found that party members are stipulated in the criminal law, although not involved in a crime shall be investigated for Party discipline and responsibility shouldbe depending on the specific circumstances shall be given a warning until expelled punishment. This situation and a difference is that the former regulation behavior has been suspected of a crime, the feeling is quite strict, and the latter for the behavior not involving crime, only the objective performance of the provisions of the criminal code of behavior, but the plot is a crime to slightly. < Regulations > the 29 provisions, Party organizations in the discipline review found that party members and other illegal behavior, affect the party's image, the damage to the party, the state and the people's interests, we should depend on the situation Seriousness given disciplinary action. The loss of Party members, seriously damaging the party's image of behavior, should be given expelled from the party. At this article is party member is in violation of the criminal law outside the other illegal acts, such as violates the public security administration punishment law, customs law, financial laws and regulations behavior. The fourth is < cases > Article 32 stipulates, minor party members and the circumstances of the crime, the people's Procuratorate shall make a decision not to initiate a prosecution, or the people's court shall make a conviction and exempted from criminal punishment shall be given within the party is removed from his post, probation or expelled from the party. Party members and crime, sheets were fined in accordance with For acts; the principal Ordinance amended the provisions of the preceding paragraph. This is the new content, in order to achieve Ji method effectiveconvergence. Five is < > the thirty third article 10 of the provisions, the Party member due to an intentional crime is sentenced to criminal law (including probation) sheets or additional deprivation of political rights; due to negligence crime and was sentenced to three years or more (excluding three years) a penalty, shall give expelled punishment. Due to negligence crime is convicted and sentenced to three years (including three years) in prison or be sentenced to public surveillance, detention, shall in general be expelled from the party. For the individual may not be expelled from the party, should control Approval. This is followed and retained the original > < Regulations the provisions of punishment party authorization rules and report to a level party organizations. For is "party members with criminal acts, and by the criminal punishment, generally should be expelled from the party". The fifth chapter of probationary Party member of the discipline and discipline after missing members of the treatment and punishment decisions, such as the implementation of the provisions, clear the related party discipline and punishment decision made after, for duties, wages and other relevant alteration formalities for the longest time. 2, sub sub section will the original regulations of10 categories of acts of violation of discipline integration revised into 6 categories, respectively, in violation of the punishments for acts of political discipline "in violation of discipline behavior of punishment" in violation of integrity of disciplinary action points "of violation punishments for actsof mass discipline" "the violation of work discipline, punishment" in violation of discipline of life behavior punishment "6 chapters. 3, annex" Supplementary Provisions "clear authority making supplementary provisions of, cases of interpretative organ, as well as regulations implementation time and retroactivity etc.. 11 (3) learning understanding > < regulations needs to grasp several key problems The first problem -- about the violation of political discipline behavior > < new ordinance chapter 6 the political discipline column for the six disciplines, that is the main opposition to Party leadership and the opposition of the basic theory, basic line, basic program and basic experience, basic requirements of misconduct made provisions of the disposition, especially the eighteen since the CPC Central Committee put forward the Yan Mingzheng treatment of discipline and political rules requirements and practical achievements transformation for Discipline article, increase the false debate central policies, cliques, against the organization review, make no discipline of the principle of harmony terms. These are the party's eighteen years in comprehensive strictly Process combined with the practice of rich content. (1) false debate the central policies and undermine the Party of centralized and unified the problem is made in accordance with the provisions of the party constitution. Constitution in general programme requirements adhere to democratic centralism is one of the requirements of the construction of the party must adhere to the four cardinal. Applicationof this principle is not only the party the basic organization principle and is also the mass line in party life, it requires that we must fully develop inner-party democracy, respect for the dominant position of Party members, safeguarding the Party member democratic rights, give full play to the enthusiasm and creativity of the party organizations at all levels and Party members, at the same time, also must implement the right concentration, ensure the party's mission < the chaos in unity and concerted action to ensure that the party's decision to get quickly and effectively implementing. The Party Central Committee formulated the major principles and policies, through different channels and ways, fully listen to the party organizations and Party members of the opinions and suggestions, but 12 is some people face to face not to say back blather "" will not say, after the meeting said, "" Taiwan does not say, and nonsense ", in fact, not only disrupt the people thought, some causing serious consequences, the damage to the Party of the centralized and unified, hinder the central policy implementation, but also a serious violation of the democratic system of principles. There is no doubt that shall, in accordance with the Regulations > 4 Specified in Article 6 to give the appropriate punishment. For did not cause serious consequences, to give criticism and education or the corresponding tissue processing. (2) about the destruction of the party's unity < New Regulations > the forty eighth to fifty second article, to damage Party's unity unified and violation of political discipline, punishment situationmade explicit provisions. Article 52 of the new "in the party get round group, gangs seek private gain, cliques, cultivate private forces or through the exchange of interests, for their own to create momentum and other activities to gain political capital, given a serious warning or withdraw from their party posts disposition; if the circumstances are serious, to give Leave a party to observation or expelled from the party. (3) on against the organization review of the provisions of the constitution, party loyalty honesty is party members must comply with the obligations. Members must obey the organization decision, shall not violate the organization decided encounters by asking questions to find organization, rely on the organization, shall not deceive the organization, against the organization. For example, after the investigation does not take the initiative to explain the situation, but to engage in offensive and defensive alliance, hiding the stolen money is against survey organization, is a violation of the behavior of political discipline. Article 24 of the original > < Regulations, although the provisions of the interference, hinder group review the behavior of the fabric can be severely or 13 Aggravated punishment, but did not put this kind of behavior alone as a discipline for qualitative amount of discipline. > < new regulations increase the Article 57, "anti organization review, one of the following acts, given a warning or serious warning; if the circumstances are relatively serious, giving removed from or placed on probation within the party post; if the circumstances are serious, give。
(完整版)数字图像处理每章课后题参考答案
数字图像处理每章课后题参考答案第一章和第二章作业:1.简述数字图像处理的研究内容。
2.什么是图像工程?根据抽象程度和研究方法等的不同,图像工程可分为哪几个层次?每个层次包含哪些研究内容?3.列举并简述常用表色系。
1.简述数字图像处理的研究内容?答:数字图像处理的主要研究内容,根据其主要的处理流程与处理目标大致可以分为图像信息的描述、图像信息的处理、图像信息的分析、图像信息的编码以及图像信息的显示等几个方面,将这几个方面展开,具体有以下的研究方向:1.图像数字化,2.图像增强,3.图像几何变换,4.图像恢复,5.图像重建,6.图像隐藏,7.图像变换,8.图像编码,9.图像识别与理解。
2.什么是图像工程?根据抽象程度和研究方法等的不同,图像工程可分为哪几个层次?每个层次包含哪些研究内容?答:图像工程是一门系统地研究各种图像理论、技术和应用的新的交叉科学。
根据抽象程度、研究方法、操作对象和数据量等的不同,图像工程可分为三个层次:图像处理、图像分析、图像理解。
图像处理着重强调在图像之间进行的变换。
比较狭义的图像处理主要满足对图像进行各种加工以改善图像的视觉效果。
图像处理主要在图像的像素级上进行处理,处理的数据量非常大。
图像分析则主要是对图像中感兴趣的目标进行检测和测量,以获得它们的客观信息从而建立对图像的描述。
图像分析处于中层,分割和特征提取把原来以像素描述的图像转变成比较简洁的非图形式描述。
图像理解的重点是进一步研究图像中各目标的性质和它们之间的相互联系,并得出对图像内容含义的理解以及对原来客观场景的解释,从而指导和规划行为。
图像理解主要描述高层的操作,基本上根据较抽象地描述进行解析、判断、决策,其处理过程与方法与人类的思维推理有许多相似之处。
第三章图像基本概念1.图像量化时,如果量化级比较小时会出现什么现象?为什么?答:当实际场景中存在如天空、白色墙面、人脸等灰度变化比较平缓的区域时,采用比较低的量化级数,则这类图像会在画面上产生伪轮廓(即原始场景中不存在的轮廓)。
数字图像处理 综合作业2
综合作业二( 春季学期)一.对X1照片图像增强 (3)1.1 直方图增强 (3)1.1.1 直方图拉伸增加对比度 (3)1.1.2直方图均衡 (4)1.2 伪彩色增强 (5)1.2.1等密度分割法 (5)1.2.2多波段合成伪彩色显示 (7)二.对x2照片图像增强 (9)2.1 滤波 (9)2.1.1各种滤波器 (9)2.1.2 中值滤波 (11)2.1.3 二阶butterworth滤波 (13)2.2 直方图增强 (15)三.边缘提取及增强 (17)3.1 对x1边缘提取及复合 (17)3.1.1 对x1边缘提取 (17)3.1.2 对x1边缘复合 (18)3.2对x2边缘提取及复合 (19)3.2.1 直接对原图x2边缘提取 (19)3.2.2 去噪后边缘提取 (20)3.2.3 对x2边缘复合 (21)一.对X1照片图像增强1.1 直方图增强1.1.1 直方图拉伸增加对比度为了增强图像,观察x1,我们考虑增加图像的对比度,看是否能使图像更清晰。
具体的编程思路是,读入x1图像,运用matlab自带的imadjust函数,对比所得结果,具体程序见附录1.1.1(a),实验结果见图1.1.1(1)。
1.1.1(a)结论:由图1.1.1(a)对比发现,左右两边基本没有区别,基本没有图像增强效果。
我们考虑到运用imadjust函数可以得到原图的负片,即将原灰度图白色的地方变成黑色,黑色的地方变成白色,这种效果可能使X1图像自身对比更鲜明,起到图像增强的作用,具体程序见附录1.1.1(2),实验结果见图1.1.1(b)。
1.1.1(b)结论:由图1.1.1(b)的对比发现,从人眼的视觉角度来看,右图比起左图,在感官上比较舒适,似乎有点图像增强的意思,但总体上,效果还不是很好。
1.1.2直方图均衡在第三章的作业习题里,我们已经接触过直方图均衡,它是一种利用图像直方图对对比度进行调整的方法,也是图像增强常用的方法之一。
《数字图像处理》习题参考答案
《数字图像处理》习题参考答案《数字图像处理》习题参考答案第1 章概述1.1 连续图像和数字图像如何相互转换?答:数字图像将图像看成是许多⼤⼩相同、形状⼀致的像素组成。
这样,数字图像可以⽤⼆维矩阵表⽰。
将⾃然界的图像通过光学系统成像并由电⼦器件或系统转化为模拟图像(连续图像)信号,再由模拟/数字转化器(ADC)得到原始的数字图像信号。
图像的数字化包括离散和量化两个主要步骤。
在空间将连续坐标过程称为离散化,⽽进⼀步将图像的幅度值(可能是灰度或⾊彩)整数化的过程称为量化。
1.2 采⽤数字图像处理有何优点?答:数字图像处理与光学等模拟⽅式相⽐具有以下鲜明的特点:1.具有数字信号处理技术共有的特点。
(1)处理精度⾼。
(2)重现性能好。
(3)灵活性⾼。
2.数字图像处理后的图像是供⼈观察和评价的,也可能作为机器视觉的预处理结果。
3.数字图像处理技术适⽤⾯宽。
4.数字图像处理技术综合性强。
1.3 数字图像处理主要包括哪些研究容?答:图像处理的任务是将客观世界的景象进⾏获取并转化为数字图像、进⾏增强、变换、编码、恢复、重建、编码和压缩、分割等处理,它将⼀幅图像转化为另⼀幅具有新的意义的图像。
1.4 讨论数字图像处理系统的组成。
列举你熟悉的图像处理系统并分析它们的组成和功能。
答:如图1.8,数字图像处理系统是应⽤计算机或专⽤数字设备对图像信息进⾏处理的信息系统。
图像处理系统包括图像处理硬件和图像处理软件。
图像处理硬件主要由图像输⼊设备、图像运算处理设备(微计算机)、图像存储器、图像输出设备等组成。
软件系统包括操作系统、控制软件及应⽤软件等。
图1.8 数字图像处理系统结构图11.5 常见的数字图像处理开发⼯具有哪些?各有什么特点?答.⽬前图像处理系统开发的主流⼯具为 Visual C++(⾯向对象可视化集成⼯具)和 MATLAB 的图像处理⼯具箱(Image Processing Tool box)。
两种开发⼯具各有所长且有相互间的软件接⼝。
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。
昆明理工大学数字图像处理课程综合报告(大作业)
数字图像处理课程综合报告学生姓名:xxx学号:2012xxxxxxxx学院:理学院专业年级:2012级电子信息科学与技术指导老师:桂进斌目录实验二:反色与二值化: (3)实验三:灰度变换 (5)线性变化 (8)指数变化 (9)对数变换 (11)实验四:图像几何变换 (12)图像平移 (15)图像旋转 (17)水平镜像 (20)垂直镜像 (21)实验五:直方图均衡化 (22)实验六:图像的平滑与锐化 (25)均值滤波 (27)中值滤波 (29)梯度锐化 (32)Sobel算子锐化 (33)实验七:彩色图像处理 (34)读取R分量 (34)读取G分量 (36)读取B分量 (38)实验八:图像频域高通和低通滤波变换 (40)低通滤波 (41)高通滤波 (44)实验二:反色与二值化:图像的反色就是依次求出每个像素点的补色,由于用的是256位的图像,所以只需要使用255减去原本像素的色值即可。
图像的二值化,就是将图像上的像素点的灰度值设置为0或255,也就是将整个图像呈现出明显的只有黑和白的视觉效果。
在实验前期开发环境框架的搭建中就已经拿到图像在内存中的首地址存于Imgdata指针中,并开辟了一个用于存放处理后数据的内存空间Imgdata_tmp。
在以后的图像处理算法中只需要直接对Imgdata指向的数据进行处理,并把处理结果存放在Imgdata_tmp中即可。
实现代码:void MyBmp::Binaryzation(CDC *pDC){//binaryzation二值化if(m_DibHead==NULL)MessageBox(NULL,"获取文件头失败!","错误",MB_OK);if(m_hPalette!=NULL){HDC hdc=pDC->GetSafeHdc();::SelectPalette(hdc,m_hPalette,TRUE);}pDC->SetStretchBltMode(COLORONCOLOR);int x = m_DibHead->biWidth;int y = m_DibHead->biHeight;TmpBmp = new unsigned char[m_ImageSize];memset(TmpBmp,255,x*y);char temp;int ccc = 0;for (int i = 0;i<y; ++i)//行数for (int j = 0;j<x;++j){ccc++;temp = *(m_Image+i*x+j);if ((10*temp+10)>=255){TmpBmp[i*x+j] = (char)255;}elseTmpBmp[i*x+j] = 0;}//memcpy(m_Image,TmpBmp,x*y);二值化效果:char temp;for (int i = 0;i<y; ++i)//行数for (int j = 0;j<x;++j){temp = m_Image[i*x+j];TmpBmp[i*x+j] = 255 - temp;}//memcpy(m_Image,TmpBmp,x*y);::StretchDIBits(pDC->GetSafeHdc(),500,0,((400<=(m_DibHead->biW idth))?400:(m_DibHead->biWidth)),((400<=(m_DibHead->biHeight))?400:(m_DibHead->biHeight)),0,0, m_DibHead->biWidth,m_DibHead->biHeight,TmpBmp,(LPBITMAPINFO)m_DibHead,DIB_RGB_COLORS,SRCCOPY);delete[] TmpBmp;TmpBmp = NULL;}反色效果:实验三:灰度变换灰度线性变换是灰度变换的一种,图像的灰度变换通过建立灰度映射来调整源图像的灰度从而达到图像增强的目的。
数字图像处理大作业
数字图像处理大作业学号:姓名:班级:数字图像处理作业用自己拍摄的图像,完成以下作业:1,用Matlab语言完成如下实验:1)打开一个BMP文件2)将其局部区域的灰度值进行改变3)另存为一个新的BMP文件2,Matlab编程实现图像傅立叶高通、低通滤波,给出算法原理及实验结果。
3,找一幅曝光不足的灰度(或彩色)图像,用Matlab按照直方图均衡化的方法进行处理。
4,用Matlab打开一幅图像,添加椒盐、高斯噪声,然后使用邻域平均法、中值滤波法进行平滑。
5,用Matlab打开一幅图像,利用Roberts梯度法、Sobel算子和拉普拉斯算子进行锐化,并比较结果。
以上作业,严禁抄袭。
作业请注明学号,姓名,班级,电话号码。
将纸质版于2012-06-06晚7:00交至B529房间。
1,用Matlab语言完成如下实验:1)打开一个BMP文件2)将其局部区域的灰度值进行改变3)另存为一个新的BMP文件%文件名为way01.bmp 源程序如下:clear all;f=imread('way.bmp');f1=rgb2gray(f); %ת»»Îª»Ò¶Èͼfigure(1);imshow(f1);imwrite(f1,'way01.bmp');f1(100:150,100:120)=256; %¾Ö²¿¸Ä±ä»Ò¶ÈÖµfigure(2);imshow(f1);运行结果为:注:源文件名为way.jpg2,Matlab编程实现图像傅立叶高通、低通滤波,给出算法原理及实验结果。
1)傅里叶高通滤波:源程序为:clear all;I=imread('way01.bmp');figure(1);imshow(I);I=double(I);f=fft2(I);g=fftshift(f);[M,N]=size(g);n1=floor(M/2);n2=floor(N/2);d0=5;for i=1:Mfor j=1:Nd=sqrt((i-n1)^2+(j-n2)^2);if d>=d0h1=1;elseh1=0;endg1(i,j)=(h1+0.5)*g(i,j);endendg2=ifftshift(g1);g3=uint8(real(ifft2(g2))); figure(2);imshow(g3);title('¸ßͨÂ˲¨½á运行结果为:2)傅里叶低通滤波:源程序为:clear all;I=imread('way01.bmp');figure(1);imshow(I);I=double(I);f=fft2(I); g=fftshift(f); [M,N]=size(g);n1=floor(M/2);n2=floor(N/2);d0=30;for i=1:Mfor j=1:Nd=sqrt((i-n1)^2+(j-n2)^2);if d<=d0h1=1;elseh1=0;endg1(i,j)=(h1+0)*g(i,j);endendg2=ifftshift(g1);g3=uint8(real(ifft2(g2))); figure(2);imshow(g3);title('µÍͨÂ˲¨½á¹û')运行结果为:3,找一幅曝光不足的灰度(或彩色)图像,用Matlab按照直方图均衡化的方法进行处理。
数字图像处理第二章课后习题及中文版解答
数字图像处理第⼆章课后习题及中⽂版解答数字图像处理(冈萨雷斯版,第⼆版)课后习题及解答(部分)Ch 22.1使⽤2.1节提供的背景信息,并采⽤纯⼏何⽅法,如果纸上的打印点离眼睛0.2m 远,估计眼睛能辨别的最⼩打印点的直径。
为了简明起见,假定当在黄斑处的像点变得远⽐视⽹膜区域的接收器(锥状体)直径⼩的时候,视觉系统已经不能检测到该点。
进⼀步假定黄斑可⽤1.5mm × 1.5mm 的⽅阵模型化,并且杆状体和锥状体间的空间在该阵列上的均匀分布。
解:对应点的视⽹膜图像的直径x 可通过如下图题2.1所⽰的相似三⾓形⼏何关系得到,即()()220.20.014d x = 解得x =0.07d 。
根据2.1节内容,我们知道:如果把黄斑想象为⼀个有337000个成像单元的正⽅形传感器阵列,它转换成⼀个⼤⼩580×580成像单元的阵列。
假设成像单元之间的间距相等,这表明在总长为1.5 mm 的⼀条线上有580个成像单元和579个成像单元间隔。
则每个成像单元和成像单元间隔的⼤⼩为s =[(1.5 mm)/1159]=1.3×10-6 m 。
如果在黄斑上的成像点的⼤⼩是⼩于⼀个可分辨的成像单元,在我们可以认为改点对于眼睛来说不可见。
换句话说,眼睛不能检测到以下直径的点:x =0.07d<1.3×10-6m ,即d <18.6×10-6 m 。
下图附带解释:因为眼睛对近处的物体聚焦时,肌⾁会使晶状体变得较厚,折射能⼒也相对提⾼,此时物体离眼睛距离0.2 m ,相对较近。
⽽当晶状体的折射能⼒由最⼩变到最⼤时,晶状体的聚焦中⼼与视⽹膜的距离由17 mm 缩⼩到14 mm ,所以此图中选取14mm(原书图2.3选取的是17 mm)。
图题2.12.2 当在⽩天进⼊⼀个⿊暗的剧场时,在能看清并找到空座位时要⽤⼀段时间适应,2.1节(视觉感知要素)描述的视觉过程在这种情况下起什么作⽤?解:根据⼈眼的亮度适应性,1)由于户外与剧场亮度差异很⼤,因此当⼈进⼊⼀个⿊暗的剧场时,⽆法适应如此⼤的亮度差异,在剧场中什么也看不见;2)⼈眼不断调节亮度适应范围,逐渐的将视觉亮度中⼼调整到剧场的亮度范围,因此⼜可以看见、分清场景中的物体了。
数字图像处理试题答案
数字图像处理试题答案一、选择题1. 数字图像处理中,用于减少图像噪声的常用方法是什么?A. 锐化B. 滤波C. 边缘增强D. 色彩调整答案:B. 滤波2. 在数字图像处理中,以下哪种颜色空间是以人类视觉感知为基础设计的?A. RGB颜色空间B. CMYK颜色空间C. HSI颜色空间D. YCbCr颜色空间答案:C. HSI颜色空间3. 以下哪种算法常用于图像的边缘检测?A. 拉普拉斯算子B. 高斯模糊C. 索贝尔算子D. 中值滤波答案:C. 索贝尔算子4. 在数字图像处理中,直方图均衡化的主要作用是什么?A. 提高图像对比度B. 降低图像饱和度C. 增强图像细节D. 压缩图像颜色答案:A. 提高图像对比度5. 以下哪种格式是用于存储具有透明通道的图像文件?A. JPEGB. PNGC. GIFD. BMP答案:B. PNG二、填空题1. 在数字图像处理中,__________是指图像中相邻像素点的灰度值的相似程度,它是图像质量的一个重要指标。
答案:平滑性2. 为了在图像中突出显示特定区域,可以通过调整__________来增强或减弱这些区域的对比度。
答案:对比度3. 在进行图像压缩时,__________是一种常用的有损压缩方法,它可以有效地减小图像文件的大小。
答案:JPEG4. 通过__________技术,可以将图像从一种颜色空间转换到另一种颜色空间,以适应不同的应用需求。
答案:颜色空间转换5. 在图像处理中,__________是一种通过模拟人眼对不同频率细节的敏感度来调整图像的方法。
答案:频率域滤波三、简答题1. 请简述数字图像处理中的噪声类型及其来源。
答:数字图像处理中的噪声主要来源于图像捕获、传输和处理过程。
常见的噪声类型包括高斯噪声、椒盐噪声和散粒噪声。
高斯噪声是由于图像传感器或传输过程中的随机误差引起的,其分布符合高斯分布;椒盐噪声通常出现在压缩图像中,表现为图像中随机分布的黑点和白点;散粒噪声则是由于图像传感器的不均匀性或光照不均造成的颗粒状效果。
《数字图像处理》习题参考答案
1《数字图像处理》 习题参考答案第1章概述1.1连续图像和数字图像如何相互转换?答:数字图像将图像看成是许多大小相同、形状一致的像素组成。
这样,数字图像可以用二维矩阵表示。
将自然界的图像通过光学系统成像并由电子器件或系统转化为模拟图像 (连续图像)信号,再由模拟 /数字转化器(ADC )得到原始的数字图像信号。
图像的数字化包括离散和量化两个主要步骤。
在空间将连续坐标过程称为离散化,而进一步将图像的幅度值(可能是灰度或色彩)整数化的过程称为量化。
1.2采用数字图像处理有何优点?答:数字图像处理与光学等模拟方式相比具有以下鲜明的特点:1 •具有数字信号处理技术共有的特点。
(1)处理精度高。
(2)重现性能好。
(3)灵活性高。
2•数字图像处理后的图像是供人观察和评价的,也可能作为机器视觉的预处理结果。
3•数字图像处理技术适用面宽。
4 •数字图像处理技术综合性强。
1.3数字图像处理主要包括哪些研究内容?答:图像处理的任务是将客观世界的景象进行获取并转化为数字图像、进行增强、变换、编码、恢复、重建、编码和压缩、分割等处理,它将一幅图像转化为另一幅具有新的意义的 图像。
1.4讨论数字图像处理系统的组成。
列举你熟悉的图像处理系统并分析它们的组成和功能。
答:如图1.8,数字图像处理系统是应用计算机或专用数字设备对图像信息进行处理的 信息系统。
图像处理系统包括图像处理硬件和图像处理软件。
图像处理硬件主要由图像输入设备、图像运算处理设备(微计算机) 、图像存储器、图像输出设备等组成。
软件系统包括操作系统、控制软件及应用软件等。
1.5 常见的数字图像处理开发工具有哪些?各有什么特点?答.目前图像处理系统开发的主流工具为 Visual C++ (面向对象可视化集成工具)和 MATLAB 的图像t+W<住《l 塁希碎«IUIMEH 鼻爭■图1.8数字图像处理系统结构图处理工具箱(Image Processing Tool box )。
数字图像处理第二章作业
第二章数字图像处理的基本概念2. 图像数字化包括那两个过程?它们对数字化图像质量有何影响?答:图像数字化包括采样和量化两个过程。
采样:将空间上连续的图像变换成离散点的操作称为采样。
量化:将像素灰度转换成离散的整数值得过程叫量化。
影响:一般来说,采样间隔越大,所得图像像素越少,空间分辨率低,质量差,严重时出现像素呈块状的国际棋盘效应;采样间隔越小,所得图像像素数越多,空间分辨率高,图像质量好,但数据量大。
量化等级越多,所得图像层次越丰富,灰度分辨率高,图像质量好,但数据量大;量化等级越少,图像层次欠丰富,灰度分辨率低,会出现假轮廓现象,图像质量变差,但数据量小.3。
数字化图像的数据量与哪些因素有关?答:数字化前需要决定影像大小(行数M、列数N)和灰度级数G的取值.一般数字图像灰度级数G为2的整数幂。
那么一幅大小为M*N,灰度级数为G的图像所需的存储空间M*N*g(bit),称为图像的数据量.6。
什么是灰度直方图?它有哪些应用?从灰度直方图你能获得图像的哪些信息?答:灰度直方图反映的是一幅图像中各灰度级像素出项的频率之间的关系.以灰度级为横坐标,纵坐标为灰度级的频率,绘制频率同灰度级的关系图就是灰度直方图.应用:通过变换图像的灰度直方图可以,使图像更清晰,达到图像增强的目的。
获得的信息:灰度范围,灰度级的分布,整幅图像的平均亮度。
但不能反映图像像素的位置。
8。
图像处理按功能分有哪几种形式?答:按图像处理的输出形式,图像处理的基本功能可分为三种形式:(1)单幅图像-—>单幅图像;(2)多幅图像—-〉单幅图像;(3)单(或多)幅图像——>数字或符号等.12。
图像特性包括哪些类型?图像特征是图像分析的重要依据,它可以是视觉能分辨的自然特征,也可以是人为定义的某些特性或参数,即人工特征.数字图像的像素亮度、边缘轮廓等属自然特性;图像经过变换得到的频谱和灰度直方图等属人工特征.1、自然特征图像是空间景物反射或者辐射的光谱能量的记录,因而具有光谱特征、几何特征和时相特征。
《数字图像处理》大作业
1. 图像处理与计算机图形学的区别与联系是什么?答:数字图像处理,是指有计算机及其它有关的数字技术,对图像施加某种运算和处理,从而达到某种预期的目的,而计算机图形学是研究采用计算机生成,处理和显示图形的一门科学。
两者区别:(1)研究对象不同,计算机图形学研究的研究对象是能在人的视觉系统中产生视觉印象的事物,包括自然景物,拍摄的图片,用数学方法描述的图形等,而数字图像处理研究对象是图像;(2)研究内容不同,计算机图像学研究内容为图像生成,透视,消阴等,而数字图像处理研究内容为图像处理,图像分割,图像透析等;(3)研究过程不同,计算机图像学是由数学公式生成仿真图形或图像,而数字图像处理是由原始图像处理出分析结果,计算机图形与图像处理是逆过程。
两者的联系:图像处理需图形学的交互手段,图形学需要图像处理合成图像,两者有重叠。
2. 图像数字化过程中的失真有那些原因?就在减少图像失真和减少图像的数据量两者之间如何取得平衡,谈谈个人的看法。
答:图像数字化过程中失真的原因主要来自三个方面:一.采样频率太低,即未满足采样定理而造成的失真;二.外部和内部噪声的影响,例如外部的电磁波、机械运动等;三.用有限个灰度值表示自然界无限连续的灰度值必然造成失真,为了减小失真必然增加采样点,即增加图像数据量。
在减少图像失真和减少图像的数据量两者之间取得平衡,要根据图像需求保留有用信息,如军事图像只需保留反应地形地貌及目标的信息,普通照片只需满足视觉要求即可。
3. 一幅模拟彩色图像经平板扫描仪扫描后获得一幅彩色数字图像,其分辨率为1024×768像素。
若采用RGB彩色空间,红、绿、蓝三基色的灰度等级为8比特,在无压缩的情况下,在计算机中存储该图像将占用多少比特的存储空间?当用Photoshop图像处理软件去掉图像的彩色信息,只留下灰度信息,灰度等级为4比特,在无压缩的情况下,存储该图像将占用多少字节的存储空间?答:(1)采用RGB彩色空间,红、绿、蓝三基色的灰度等级为8比特,在无压缩的情况下,占存储空间大小为:1024×768×8×3=18874268bit=2.25MB(2)去掉彩色信息,只留下灰度信息,灰度等级为4比特,在无压缩的情况下,所占的存储空间大小为:1024×768×4 =3145728bit=0.375MB4. 试设计一个程序实现nn 的中值滤波器,当模板中心移过图像中每个位置时,设计一种简便的中值更新方法。
天津理工大学《数字图像处理》数字图像处理复习题2
第一章引言一。
填空题1。
数字图像是用一个数字阵列来表示的图像.数字阵列中的每个数字,表示数字图像的一个最小单位,称为像素2。
数字图像处理可以理解为两个方面的操作:从图像到非图像的一种表示,如图像测量等.5. 数字图像处理包含很多方面的研究内容。
其中,图像重建的目的是根据二维平面图像数据构造出三维物体的图像.二。
简答题1. 数字图像处理的主要研究内容包含很多方面,请列出并简述其中的4种.①图像数字化:将一幅图像以数字的形式表示。
主要包括采样和量化两个过程。
②图像增强:将一幅图像中的有用信息进行增强,同时对其无用信息进行抑制,提高图像的可观察性。
③图像的几何变换:改变图像的大小或形状.④图像变换:通过数学映射的方法,将空域的图像信息转换到频域、时频域等空间上进行分析。
如傅利叶变换等。
⑤图像识别与理解:通过对图像中各种不同的物体特征进行定量化描述后,将其所期望获得的目标物进行提取,并且对所提取的目标物进行一定的定量分析。
2. 什么是图像识别与理解?图像识别与理解是指通过对图像中各种不同的物体特征进行定量化描述后,将其所期望获得的目标物进行提取,并且对所提取的目标物进行一定的定量分析。
比如要从一幅照片上确定是否包含某个犯罪分子的人脸信息,就需要先将照片上的人脸检测出来,进而将检测出来的人脸区域进行分析,确定其是否是该犯罪分子.5。
简述图像几何变换与图像变换的区别.①图像的几何变换:改变图像的大小或形状。
比如图像的平移、旋转、放大、缩小等,这些方法在图像配准中使用较多。
②图像变换:通过数学映射的方法,将空域的图像信息转换到频域、时频域等空间上进行分析。
比如傅里叶变换、小波变换等.第二章图像的基本概念一。
填空题1。
量化可以分为均匀量化和非均匀量化两大类。
2。
采样频率是指一秒钟内的采样次数。
3。
图像因其表现方式的不同,可以分为连续图像和离散图像两大类.3.5。
对应于不同的场景内容,一般数字图像可以分为二值图像、灰度图像和彩色图像三类。
数字图像处理题库(含答案)
[题目]数字图像[参考答案]为了便于用计算机对图像进行处理,通过将二维连续(模拟)图像在空间上离散化,也即采样,并同时将二维连续图像的幅值等间隔地划分成多个等级(层次),也即均匀量化,以此来用二维数字阵列表示其中各个像素的空间位置和每个像素的灰度级数(灰度值)的图像形式称为数字图像。
图像处理[参考答案]是指对图像信息进行加工以满足人的视觉或应用需求的行为。
题目]数字图像处理[参考答案]是指利用计算机技术或其他数字技术,对一图像信息进行某此数学运算及各种加工处理,以改善图像的视觉效果和提高图像实用性的技术。
一、绪论(名词解释,易,3分)[题目]图像[参考答案]是指用各种观测系统以不同形式和手段观测客观世界而获得的、可以直接或间接作用于人的视觉系统而产生的视知觉的实体。
一、绪论(简答题,难,6分)[题目]什么是图像?如何区分数字图像和模拟图像?[参考答案]“图”是物体透射或反射光的分布,是客观存在的。
“像”是人的视觉系统对图在大脑中形成的印象或认识,是人的感觉。
图像是图和像的有机结合,既反映物体的客观存在,又体现人的心理因素;图像是对客观存在的物体的一种相似性的生动模仿或描述,或者说图像是客观对象的一种可视表示,它包含了被描述对象的有关信息。
模拟图像是空间坐标和亮度(或色彩)都连续变化的图像;数字图像是空间坐标和亮度(或色彩)均不连续的、用离散数字(一般是整数)表示的图像。
[题目]简述研究图像恢复的基本思路。
[参考答案]基本思路是,从图像退化的数学或概率模型出发,研究改进图像的外观,从而使恢复以后的图像尽可能地反映原始图像的本来面日,从而获得与景物真实面貌相像的图像。
一、绪论(简答题,易,5分)[题目]简述研究图像变换的基本思路。
[参考答案]基本思路是通过数学方法和图像变换算法对图像的某种变换,以便简化图像进一步处理的过程,或在进一步的图像处理中获得更好的处理效果。
一、绪论(简答题,易,5分)[题目]简述一个你所熟悉的图像处理的应用实例。
中国地质大学(北京)《数字图像处理》在线作业-00002
地大《数字图像处理》在线作业-00002一幅数字图像是:()A:一个观测系统;B:一个有许多像素排列而成的实体;C:一个 2-D 数组中的元素D:一个 3-D 空间的场景。
参考选项:B以下几个对直方图规定化的两种映射方式( SML 与 GML )的叙述中正确的是:()A:SML 的误差一定大于 GML ;B:原始直方图与规定化直方图中的灰度级数相等时( M=N ) ,SML 的误差一定等于 GML ;C:NM 时, SML 的误差一定大于 GML ;D:SML 与 GML 均是统计无偏的。
参考选项:B如果将均匀噪声的定义范围增加一倍,则其均值()A:不变B:不定C:增加一倍D:增加两倍参考选项:B利用平滑滤波器可对图像进行低通滤波,消除噪声,但同时模糊了细节。
以下哪项措施不能减小图像的模糊程度:()A:增加对平滑滤波器输出的或值处理(即仅保留大于或值的输出):B:采用中值滤波的方法;C:采用领域平均处理;D:适当减小平滑滤波器的领域操作模板。
参考选项:C模糊造成的退化()A:会将形成规则的图案变得不太规则B:会导致目标图案产生叠影C:会导致目标图案变大D:会使图像的空间分辨率下降参考选项:C设在工业检测中工件的图像受到零均值不相关噪声的影响。
如果工件采集装置每秒可采集 25幅图,要采用图像平均方法将噪声的方差减少为单幅图像的1/10,那么工件需保持多长时间固定在采集装置前?()A:1sB:4sC:10sD:25s参考选项:B当改变图像的空间分辨率时,受影响最大的是图像中的:()A:纹理区域(有许多重复单元的区域);B:灰度平滑的区域;C:目标边界区域;D:灰度渐变区域。
参考选项:A对于低通和高通巴特沃斯滤波器叙述不正确的是:())A:均有相同的截止频率;B:均能减弱振铃效应;C:处理后的图像均比用理想低通和高通处理的要过渡光滑一些;D:都可用于消除虚假轮廓。
参考选项:A在 BMP 格式、 GIF 格式、 TIFF 格式和 JPEG格式中:()( 没有压缩 ) A:表示同一副图像,BMP 格式使用的数据量最多;B:GIF 格式独立于操作系统;C:每种格式都有文件头 ,其中 TIFF 格式的最复杂;D:一个 JPEG格式的数据文件中可存放多幅图像。
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综合作业二( 春季学期)一.对X1照片图像增强 (3)1.1 直方图增强 (3)1.1.1 直方图拉伸增加对比度 (3)1.1.2直方图均衡 (4)1.2 伪彩色增强 (5)1.2.1等密度分割法 (5)1.2.2多波段合成伪彩色显示 (7)二.对x2照片图像增强 (9)2.1 滤波 (9)2.1.1各种滤波器 (9)2.1.2 中值滤波 (11)2.1.3 二阶butterworth滤波 (13)2.2 直方图增强 (15)三.边缘提取及增强 (17)3.1 对x1边缘提取及复合 (17)3.1.1 对x1边缘提取 (17)3.1.2 对x1边缘复合 (18)3.2对x2边缘提取及复合 (19)3.2.1 直接对原图x2边缘提取 (19)3.2.2 去噪后边缘提取 (20)3.2.3 对x2边缘复合 (21)一.对X1照片图像增强1.1 直方图增强1.1.1 直方图拉伸增加对比度为了增强图像,观察x1,我们考虑增加图像的对比度,看是否能使图像更清晰。
具体的编程思路是,读入x1图像,运用matlab自带的imadjust函数,对比所得结果,具体程序见附录1.1.1(a),实验结果见图1.1.1(1)。
1.1.1(a)结论:由图1.1.1(a)对比发现,左右两边基本没有区别,基本没有图像增强效果。
我们考虑到运用imadjust函数可以得到原图的负片,即将原灰度图白色的地方变成黑色,黑色的地方变成白色,这种效果可能使X1图像自身对比更鲜明,起到图像增强的作用,具体程序见附录1.1.1(2),实验结果见图1.1.1(b)。
1.1.1(b)结论:由图1.1.1(b)的对比发现,从人眼的视觉角度来看,右图比起左图,在感官上比较舒适,似乎有点图像增强的意思,但总体上,效果还不是很好。
1.1.2直方图均衡在第三章的作业习题里,我们已经接触过直方图均衡,它是一种利用图像直方图对对比度进行调整的方法,也是图像增强常用的方法之一。
我们的编程思路是运用matlab中自带的一些函数对原图进行处理,具体程序见附录1.1.2,实验结果见图1.1.2。
1.1.2结论:由图1.1.2的对比,我们可以发现直方图均衡化后的图像整体变亮,图片中部分位置变得清晰一些,部分位置灰度值过高,图像有些发白,没有得到好的图像增强效果,甚至发白部位阻碍医生观察骨骼细节。
原因是因为这种方法对处理的数据不加选择,当原图的直方图有高峰时,经处理后对比度会不自然的过分增强。
1.2 伪彩色增强1.2.1等密度分割法对图像中各像元亮度值进行统计,确定其最小值和最大值,确定分割的等级N,计算出分割的间隔再对输入图像的每一个像元进行亮度转换,为像元新值赋色。
(1)matlab自带函数grayslice(I,n)(源程序:color1.m)将灰度图X1均匀量化为n个等级,然后利用jet映射将其转化为伪彩色图像x。
程序见附录1.2.1(1)1.2.1(a) N=81.2.1(b) N=641.2.1(c) n=256分析:由上面三组图像可知,当分割等级越大,所呈现的效果越好。
(2)自编程序(源程序:color2.m)将图像X1按灰度分为11份R=0:256 间隔为256/10G=0到256 再到0 间隔为256/5B=256:0 间隔为256/101.2.1(d)分析:从上面各图的分析我们知道n越大,效果越好。
但对比利用grayslice(I,n)函数n=8时的效果,自编程序n=11时的效果没有很好,可能是颜色映射不恰当,导致效果不好。
1.2.2多波段合成伪彩色显示(源程序:color.m)对同一幅图像在不同波长获得多幅图像,可采用多种变换方式,最后合成R、G、B图像进而形成为彩色图像显示。
在这里使用分段线性映射法。
实验结果见1.2.2.程序见附录1.2.2.1.2.2分析:对比利用密度分割法产生的效果,多波段合成伪彩色显示法的效果不是很好,反而将图像变得更加模糊。
结论:通过对图像进行伪彩色处理,主要得出以下两点。
(1)对图像进行伪彩色处理时,不同的伪彩色处理方法有不同的效果,要选择合适的处理方法。
(2)不同的颜色映射法也有不同的效果,根据图像选择合适的颜色映射法。
二.对x2照片图像增强2.1 滤波首先我们先分别观察一下X2的在MATLAB中的原始图像和频谱分布情况。
因为我们观察到X2是彩色图,所以我们需要利用rgb2gray函数将它转换成灰度图再进行处理。
X2的原始图像和频谱分布图如下图2.1所示:2.1我们观察到X2的灰度图存在较严重的椒盐噪声,其频谱图也存在一个十字叉的亮线,但是围绕中间亮点又有一个矩型噪声。
综上,X2存在明显的噪声近似于椒盐噪声,所以我们先采用“广撒网,捞大鱼”的方法进行筛选,尝试使用不同类型的滤波器对X2进行滤波处理,分析对比哪种滤波器的滤波效果最好,然后再选择滤波效果最好的滤波器进行各种参数设置,使其滤波效果最好。
2.1.1各种滤波器在这里我们使用了高斯低通滤波器,均值滤波器,中值滤波器,自适应滤波器,二维统计顺序滤波器,二阶Butterworth滤波器分别对X2图像进行滤波。
程序见附录2.1.1各种滤波结果如下图2.1.1所示:高斯低通滤波均值滤波中值滤波自适应滤波二维统计顺序滤波二阶butterworth滤波2.1.1结论:对比分析后我们发现,中值滤波对于去除噪声效果最好,第二好的是二阶butterworth滤波,而自适应滤波去除效果则较差。
所以接下来我们针对中值滤波器和二阶butterworth滤波器进行详细的参数设置,通过多次试验使其达到最好的效果。
2.1.2 中值滤波因为观察X2的原始图像和频谱分布图,我们发现X2存在很明显的椒盐噪声,所以我们可以预见到使用中值滤波对X2进行处理后会有明显的改善。
基本思路是先读入待处理图像,因为我们到观察X2是彩色图,所以我们需要利用rgb2gray函数先将它转换成灰度图,再利用中值滤波器对其进行平滑滤波,分别使用3*3窗口,5*5窗口,7*7窗口,11*11窗口进行处理,分析比较处理结果。
程序见附录2.1.2X2的处理结果如下图2.1.2所示:3*3窗口中值滤波7*7窗口中值滤波11*11窗口中值滤波 13*13窗口中值滤波2.1.2结论:正如预想的那样,中值滤波对X2会产生明显的效果。
中值滤波对于去除椒盐噪声效果明显,是因为椒盐噪声只在画面上的部分点随机出现,而中值滤波根据数据排序,将未被污染的点代替噪声点的值的概率较大,所以抑制效果好。
但是当我们选择的窗口较小时噪声依然比较严重,当我们把窗口加到11*11时只存在少数噪声,当我们把窗口加到13*13时,噪声基本消除,虽然一些细节也模糊了,但是效果最好。
2.1.3 二阶butterworth滤波基本步骤与中值滤波相似,这里不再赘述。
但是,我们认为二阶butterworth 滤波应该达不到中值滤波的效果。
另外,二阶butterworth滤波需要修改与原点的距离d0,来实现最优效果,下图2.1.3分别展示了在d0=10,12,14,16,18,20时的情况。
程序见附录2.1.3d0=10 d0=12d0=14 d0=16d0=18 d0=202.1.3结论:显而易见,无论我们怎么修改参数d0,其结果始终没有中值滤波好。
同时,我们发现就X2图像而言,当d0=14左右时,二阶butterworth滤波器的效果是最好的。
因此,为了达到对X2图像最好的处理效果,我们选择了中值滤波器进行滤波处理。
2.2 直方图增强由于在之前1.1的(1)中,我们发现通过直方图拉伸来增加对比度的方法几乎没有任何作用,所以对X2不再重复。
因为x2明显存在噪声,所以我们对2.1中去噪后的图进行直方图均衡化处理,具体程序见附录2.2,实验结果见图2.2。
2.2结论:观察并对比图2.2,我们发现,中值滤波去噪后的图像再做均衡化处理,泛白情况非常严重,严重损害了图像质量,所以直方图均衡的方法不能用于x2图像的增强。
三.边缘提取及增强图像的边缘部分对应图像上灰度变化剧烈的区域。
图像的边缘提取有多种方法,可以采用一阶微分算子,如sobel算子,Roberts算子,Prewitt算子,Canny算子。
也可以采用二阶微分算子,如Laplacian算子。
各种算子都有对应的优缺点,Sobel算子检测方法对灰度渐变和噪声较多的图像处理效果较好,但Sobel算子对边缘定位不是很准确,图像的边缘不止一个像素。
Roberts算子检测方法对具有陡峭的低噪声的图像处理效果较好,但是利用roberts算子提取边缘的结果是边缘比较粗,因此边缘的定位不是很准确。
Prewitt算子检测方法对灰度渐变和噪声较多的图像处理效果较好。
但边缘较宽,而且间断点多。
Laplacian算子法对噪声比较敏感,所以很少用该算子检测边缘,而是用来判断边缘像素视为与图像的明区还是暗区。
Canny方法不容易受噪声干扰,能够检测到真正的弱边缘。
优点在于,使用两种不同的阈值分别检测强边缘和弱边缘,并且当弱边缘和强边缘相连时,才将弱边缘包含在输出图像,它是目前边缘检测最常用的算法,效果也是最理想的。
3.1 对x1边缘提取及复合3.1.1 对x1边缘提取根据上述对边缘提取的分析,我们编写了各个边缘提取的程序,希望找到一个最好的边缘提取函数,进而得到最好的图像增强效果。
X1的具体程序见附录3.1.1,实验结果见图3.1.1。
3.1.1观察对比图3.1.1,可以很明显地发现Canny方法提取的边缘效果最好,这个结果符合我们之前的分析,所以接下来的复合边缘,我们都采取Canny方法。
3.1.2 对x1边缘复合因为对x1做直方图均衡化后,部分图像由于对比度过高而泛白,不但没有增强图像,还损害了图像的部分细节,所以复合时不再考虑叠加均衡化后的图,所以我们的思路是将canny边缘提取图叠加在原图上,进行边缘复合。
具体程序见附录3.1.2,实验结果见图3.1.2。
3.1.2结论:观察并分析3.1.2,利用canny算子提取边缘后的图像与原图进行叠加,复合后的图像轮廓更加清晰,对比度明显增强,达到了图像增强的效果。
但是提取的边缘过多,很多细节被模糊了,总体效果不是很理想,这是我们需要解决的问题,但是目前还没找到更好的办法。
3.2对x2边缘提取及复合3.2.1 直接对原图x2边缘提取因为x2是彩色图,所以要对其进行灰度转化,其他操作思路同x1。
x2的具体程序见附录3.2.1,实验结果见图3.2.1。
3.2.1结论:观察对比图3.2.1,同图3.1.1一样,也可以很明显地发现Canny 方法提取的边缘效果最好,所以接下来的复合边缘,我们也就只采取Canny方法进行图像增强。
此外,我们还发现,在提取边缘的同时,我们把噪声也当边缘提取了。