数字图像处理模拟题(双语课)
数字图像处理题库(87道)
数字图像处理1、in the hardware peripherals of image processing, which of the following equipments does not belong to the input devices?——[单选题]A Electron cameraB CCD video cameraC Desktop image scannerD Light tape正确答案：D2、The number of bits required to store an 1024*512 image of 4 gray levels is ( )——[单选题]A 256KB 512KC 1MD 2M正确答案：C3、An image of size 1024 × 1024 pixels in which the intensity of each pixel is an8 bit quantity requires the storage space ( if not compressed).——[单选题]A 1 KBB 1 MBC 2 KBD 2 MB正确答案：B4、Intensity range of 8-bit pixel image is （） .——[单选题]A 0 to 7B 0 to 15C 0 to 31D 0 to 255正确答案：D5、By its very nature, the appearance of false contours in image is because ( )——[单选题]A the number of gray levels of the image is not enoughB the spatial resolution of the image is not high enoughC the number of gray levels of the image is excessiveD the spatial resolution of the image is too enough正确答案：A6、In the process of image sampling and quantization, the appearance of checkboard effect is because ( )——[单选题]A the number of gray levels of the image is not enoughB the spatial resolution of the image is not high enoughC the number of gray levels of the image is excessiveD the spatial resolution of the image is too enough正确答案：B7、When you enter a dark room on a bright day, it takes some time to see well enough, this is the visual process or visual phenomenon of——[单选题]A Brightness adaptationB Brightness discriminationC Optical illusionD Simultaneous contrast正确答案：A8、Sampling of an image is required for （）.——[单选题]A QuantizationB SharpeningC SmoothingD Digitization正确答案：D9、An image function f(x,y) is characterized by f(x,y)=i(x,y)r(x,y) where.——[单选题]A 0<i(x,y)<1&0<r(x,y)<∞B 0<i(x,y)<1&0<r(x,y)<1C 0<i(x,y)<∞&0<r(x,y)<∞D 0<i(x,y)<∞&0<r(x,y)<1正确答案：D10、A pixel p at coordinates (x,y) has four horizontal and vertical neighbours whose coordinates are given by.——[单选题]A (x-1,y-1),(x-1,y),(x,y-1),(x,y+1)B (x+1,y),(x-1,y),(x,y+1),(x,y-1)C (x+1,y-1),(x-1,y),(x-1,y+1),(x,y+1)D (x+1,y-1),(x-1,y),(x,y+1),(x-1,y+1)正确答案：B11、The D4 distance (city distance) between p and q with coordinates (x,y), (s,t) is defined as.——[单选题]ABCD正确答案：A12、Mach bands effect——[单选题]A can be analyzed using simutaneous contrastB depends on the brightness adaptive level of human visual systemC indicates the same fact as simutaneous contrastD indicates that the actual brightness distributions of the bands are influenced by the subjective brightness curve正确答案：C13、The lens focuses light from objects onto the——[单选题]A corneaB retinaC scleraD iris正确答案：B14、The spatial resolution of an image is determined by how ( ) was carried out.——[单选题]A QuantizationB SharpeningC SmoothingD Sampling正确答案：D15、In the human visual system, the perceived intensity of a region is related to the light intensities of the regions surrounding it, this is called ( ).——[单选题]A brightness adaptationB simultaneous contrastC brightness discriminationD optical illusions正确答案：B16、The colours of an object that we perceive are determined by the nature of( ).——[单选题]A the light reflected from the objectB the light shone onto the objectC the light absorbed by the objectD the external light正确答案：A17、The human visual system can perceive approximately different light intensity levelsHowever, at any one time we can only discriminate between a much smaller number,this is indicated in the phenomenon called ( ).——[单选题]A Brightness adaptationB Brightness discriminationC Optical illusionD Simultaneous contrast正确答案：A18、Suppose there is a pixel p at coordinates (x,y), it's diagonal neighbor has four pixels, whose coordinates are given by ( ).——[单选题]A (x-1,y-1),(x-1,y),(x,y-1),(x,y+1)B (x-1,y-1),(x+1,y-1),(x-1,y+1),(x+1,y+1)C (x+1,y-1),(x-1,y),(x-1,y+1),(x,y+1)D (x+1,y-1),(x-1,y),(x,y+1),(x-1,y+1)正确答案：B19、The distance (chessboard distance) between p and q with coordinates (x,y), (s,t) is defined as. ——[单选题]ABCD20、In Matlab, which command can we use to dispaly an image?——[单选题]A imreadB imshowC imhistD imwrite正确答案：B21、In matlab, suppose x=[1 2 3 4;5 6 7 8;9 10 11 12]，after run the commandx(:,[2,3])=[];what is the size of x?——[单选题]A 1*4B 3*2C 3*4D 3*3正确答案：B22、In matlab command window, if we run the followong command,what is the result shown in the command window？X=[1 2 3 4;5 6 7 8;9 10 11 12];X(5)——[单选题]A 5B 6C 0D 10正确答案：B23、In Matlab，Suppose x is a 1*6 array，which command can delete the fifth element of x？——[单选题]A delete x(5)B delete x(4)C x(5)=[]D x(4)=[]正确答案：C24、In MATLAB，what is the result of the expression 3~=4？——[单选题]A 1B 0C 7D 1225、In matlab, the command "clear" is used to ( )——[单选题]A Shows the variable in the workspaceB Deletes all variables in the workspaceC clean the command windowD clean the figure window正确答案：B26、In MATLAB，what is the result of x after run the command x=1:2:10？——[单选题]A 1 2 3 4 5 6 7 8 9 10B 1 3 5 7 9 11C 1 3 5 7 9D 2 4 6 8 10正确答案：C27、if x=2.6 ,what is the result of round(x), floor(x), ceil(x) and fix(x)?——[单选题]A 2,2,3,2B 3,2,3,2C 3,2,3,3D 2,2,3,3正确答案：B28、In MATLAB，what is the result of the expression 3==3？——[单选题]A 1B 0C 7D 12正确答案：A29、if x=-2.6 ,what is the result of round(x), floor(x), ceil(x) and fix(x)?——[单选题]A -2,-3,-2,-2B -3,-3,-2,-2C -3,-3,-2,-3D -2,-3,-2,-330、In matlab, the command "save" is used to ( )——[单选题]A Shows the variable in the workspaceB Saves all variables in the workspace to diskC clean the command windowD clean the figure window正确答案：B31、In MATLAB，what is the result of x after run the command x=10:-2:1？——[单选题]A 10 9 8 7 6 5 4 3 2 1B 10 8 6 4 2 0C 10 8 6 4 2D 2 4 6 8 10正确答案：C32、In Matlab, which command can we use to read an image?——[单选题]A imshowB imreadC imhistD imwrite正确答案：B33、In MATLAB, what is the result of a(5) after run these two commands?A=[1 2 3 4]；A(6)=6;——[单选题]A 6B 5C 4D 0正确答案：D34、In Matlab，Suppose x is a 2*3 array，which command can delete the 5th elementof x？——[单选题]A delete x(5)B delete x(4)C x(4)=[]D x(5)=[]35、In matlab, suppose x=[1 2 3 4;5 6 7 8;9 10 11 12]，after run the commandx([1,3],:)=[];what is the size of x?——[单选题]A 3*2B 1*4C 3*4D 3*3正确答案：B36、In matlab，suppose x is a 3*4 matrix，after run the following command，what is the size of x？X=[1 2 3 4;5 6 7 8;9 10 11 12];Y=x(2,2:4);X=[x,y'];——[单选题]A 3*4B 4*3C 3*5D 5*3正确答案：C37、in Matlab，if we want to display four images in the same figure window as the layout shown in the following，which command do we need to use to display an image in the area 2?——[单选题]A subplot(1,4,2)B subplot(4,1,2)C subplot(2,2,2)D subplot(2,2,3)正确答案：C38、In matlab, suppose x=[1 2 3 4;5 6 7 8;9 10 11 12]，after run the commandx=[x;13 14 15 16];what is the size of x?——[单选题]A 3*5B 4*4C 3*4D 3*3正确答案：B39、In Matlab，Suppose x is a 1*6 array，which command can add 3 elements to x？——[单选题]A add x(7:9)B add x(3)C x(9)=10D x(9)=[]正确答案：C40、The corresponding relations between an image and its gray histogram is ( )——[单选题]A one to oneB many-to-oneC one-to-manyD all false正确答案：B41、There is a light ring on the dark background of a gray level image, can be used to make the ring thinner.——[单选题]A Median filterB Max filterC Min filterD Midpoint filter正确答案：C42、In the following four operators, which one belongs to the secondderivative? .——[单选题]A SobelB RobertsC PrewittD Laplacian正确答案：D43、When powerlaw transformation is used to as grayscale transformation,Which type of images as follows can be the transformationPerformed on for enhancement if the power is over 1?——[单选题]A Overall image intensities are on the dark sideB Overall image intensities are on the bright sideC Image details are hidden in the dark backgroundD Images have both too bright and too dark background正确答案：B44、( )can be applied for motion detection.——[单选题]A additionB substactionC multiplicationD division正确答案：B45、In the following four filters, which one belongs to a linear filter?——[单选题]A Median filterB Averaging filterC Max filterD Min filter正确答案：B46、The purpose of compressing dynamic range of image graylevles can be achieved with the help of logarithmic transformation , because ( )——[单选题]A graylevels dynamic range before transformation is larger than that after transformationB only partial range of graylevel values ha been taken after transformationC the ranges of graylevel before and after the transformation are differentD logarithmic transformation curve is monotonically increasing curve正确答案：B47、Logarithmic transform is useful if we wish to enhance details in the ( ) areas of the image, but at the expense of details in the ( ) areas.——[单选题]A dark darkB dark brightC bright darkD bright bright正确答案：B48、The range of intensity change of certain scene image obtained from camera is called ( ),which is the range from the darkest to the brighest in an image.——[单选题]A gray levelB dynamic rangeC spatial resolutionD histogram正确答案：B49、The gray level of an overexposed (washed out) image focuses on ( ) range, while the gray level of an underexposed image focuses on ( ) range.——[单选题]A low-brightness ,low-brightnessB low-brightness ,high-brightnessC high-brightness ,low-brightnessD high-brightness ,high-brightness正确答案：C50、Geometric transformation of images does not change the pixel's( ),but change the pixel's( ).——[单选题]A positon, valueB value,positionC contrast,positionD position, contrast正确答案：B51、Corresponding to different scene contents, digital image can be generally divided into three types, they are ( )——[多选题]A binary imageB gray imageC index imageD color image正确答案：ABD52、Which of the following adjacencies can eliminate ambiguity of path between pixels ( )——[多选题]A 4-adjacencyB 8-adjacencyC m-adjacencyD mixed adjacency正确答案：CD53、Image digitization process consists of two steps——[多选题]A samplingB transformationC quantizationD scanning正确答案：AC54、The retina is covered with light receptors called——[多选题]A rodsB conesC foveaD lens正确答案：AB55、Image digitization process consists of two steps，sampling and quantization. These two steps determine the ( ) and ( ) of an image, respectively.——[多选题]A Spatial resolutionB ResolutionC Intensity level resolutionD Dynamic domain正确答案：AC56、（Single choice）Which adjacency between pixels is the sufficient condition of other types of adjacency ？——[多选题]A 4-adjacencyB 8-adjacencyC m-adjacencyD mixed adjacency正确答案：A57、Three commonly-used neighbors in image processing are( )——[多选题]A 4-neighborsB 8-neighborsC diagonal neighborsD mixed neighbors正确答案：ABC58、MATLAB variable names ( )——[多选题]A must begin with a letterB can contain any combination of letters, numbers and underscore (_C must be unique in the first 31 charactersD can begin with a number正确答案：ABC59、The commonly-used histogram processing methods include ( ) and ( ).——[多选题]A histogram equalizationB histogram adjustmentC histogram specificationD histogram transform正确答案：AC60、The following spatial filters belonged to non-linear filters are ( )——[多选题]A median filterB max filterC min filterD averaging filter正确答案：ABC61、The cone body is mainly located in the middle part of the retina,and is highly sensitive to color. ——[判断题]A 正确B 错误正确答案：A62、The total range of distinct intensity levels the eye can discriminate simultaneously is rather small when compared with the total adaptation range. ——[判断题]A 正确B 错误正确答案：A63、The colours that we perceive are determined by the nature of the light absorbed by an object. ——[判断题]A 正确B 错误64、If a command is followed by a semicolon (;), result of the computation is not shown on the command window.——[判断题]A 正确B 错误正确答案：A65、If a command is followed by a commas (,), result of the computation is not shown on the command window——[判断题]A 正确B 错误正确答案：B66、In command window of Matlab, Ellipsis (…) means continuing on the next line.——[判断题]A 正确B 错误正确答案：A67、MATLAB is case sensitive: “name”, “Name” and “NAME” are consider ed different variables——[判断题]A 正确B 错误正确答案：A68、In Matlab, a two-dimensional matrix is stored in memory in Column major order.——[判断题]A 正确B 错误正确答案：A69、In MATLAB relational operators ,false is represented by 0 and true is represented by 1 (non-zero).——[判断题]A 正确B 错误70、Suppose x is a 3*4 matrix, then a(2,3) is the 8th element of x when in memory.——[判断题]A 正确B 错误正确答案：A71、In Matlab, imshow funtuntion can display images on the screen.——[判断题]A 正确B 错误正确答案：A72、Break statement terminates the execution of a loop and passes the control to the next statement after the end of the loop.——[判断题]A 正确B 错误正确答案：A73、Continue statement terminates the current pass through the loop and returns control to the top of the loop.——[判断题]A 正确B 错误正确答案：A74、In Matlab, the command window can input commands and show the results. ——[判断题]A 正确B 错误正确答案：A75、In the binary image, each pixel value is represented by 1 bit, value 1 represents white and value 0 represents ( )——[填空题]正确答案：black76、Consider the image segment shown .Two pixels p and q are at the locations shown in the figure, please compute their Euclidean（）,city-block （）andchessboard distances（）respectively。
西安交大数字图像处理双语试题
Sket tch the gray y level transformation fo for a gamma a transforma ation that wi ill produce t the image on n the right. mera capture es a 400x400 pixel imag ge of a black and white e soccer ball l on a gray b background. The 2. A digital cam ball is 30 cm in n diameter an nd is 3 m aw way from th he camera. T The camera has a field o of field of 90 9 degrees izontally and d vertically. . hori (a) W What is the diameter of f the ball in pixels, in th he image? (i) 3 pixels (ii) 10 pixels (ii i) 20 pixels (iii) 31 pixe els (iv) 63 p pixels (b) G Give the his stogram of t the image, a assuming tha at black, wh hite, and gra ay pixels hav ve the gray levels 0, 25 55, and 128, respec ctively. Assu ume that the ere are an eq qual number r of black an nd white pix xels on the b ball. g (table tenn nis) ball is 4 40 mm in diameter. How w far away must the pin ng-pong bal ll be, to be (c) A ping-pong exac ctly the sam me apparent size as the s soccer ball i in the image e? (i) 1 10 cm (ii) 0.4 m (iii) 0.7 75 m (iv) 1 m (v) 3 m era has an im mage resolu ution of 2000 x 2000 pix xels. The in ndividual sen nsor elemen nts are squar res 3. A CCD came mea asuring 10 x 10 um, wit th no spaces s between th hem. a. If f the camera a uses a lens s with focal length = 10 00 mm, wha at is the field d of view? b. A Assume the c camera is m mounted on a an airplane, pointing str raight down n at the grou und. What he eight should d the airplane fly, so that one pix xel in the ca amera corres sponds to on ne meter on n the ground d? 4. T The histogram m of a 100x x100 image with 3 bit p pixels is give en below.
数字图像处理模拟试题4套(含答案)
模拟试卷一1.对将一个像素宽度的8通路转换到4通路提出一种算法。
2.（A）试提出一种过程来求一个邻域的中值？（B）试提出一种技术，逐像素地移动领域的中心来更新中值。
（会了）3.证明如式所示的拉普拉斯变换是各向同性的（旋转不变）。
需要下列轴旋转角的坐标方程：其中为非旋转坐标，而为旋转坐标。
4.获得对应于式子到式子的带阻滤波器的带通滤波器的等式。
5.给定的图象，那么一个级金字塔是减少还是增加了表示图象所需的数据量？压缩或扩展率是多少？6.考虑灰度级数据{12，12，13，13，10，13，57，54}的一条8像素的线。
这条线已经经过精度为6比特的均匀量化。
构造它的3位IGS编码。
7.一个零记忆高斯信源率失真函数如下：请绘制出这个函数的曲线。
8.证明二元表达式的正确性。
模拟试卷一参考答案1.2.（A）在数字上拣取为的值，它的中值是的最大值。
（B）一旦值已经被分类一次，我们仅仅是删除在缓慢移动向附近的轨迹的值，插入首要移动的值到分类排列的最恰当位置。
3.4.带通滤波器是从1减去带阻滤波器获得的：然后：（a）理想的带通滤波器：（b） Butterworth带通滤波器：（c）高斯带通滤波器：5.数据的数量在这个级金字塔中是被限定在4/3之内的：又因为 ,因此我们可以得到以下的结果:6.7.8.模拟试卷二1.考虑以下所示的图像分割：（A）令并计算p和q间的4，8，m通路的最短长度。
如果在这两点间不存在特殊通路，请解释原因。
（B）对重复上题。
2.使用式给出的拉普拉斯变换的定义，证明将一幅图像减去其相应拉普拉斯图像等同于对图像做反锐化掩模处理。
3.证明式子的正确性。
4.说明二维正弦函数的傅里叶变换是共轭脉冲对：提示：用式的连续傅里叶变换并以指数项描述正弦。
5.给定的图像，那么一个级金字塔是减少还是增加了表示图像所需的数据量？压缩或扩展率是多少？6.考虑灰度级数据{12，12，13，13，10，13，57，54}的一条8像素的线。
数字图像处理试题及答案
数字图像处理试题及答案一、单项选择题（每题2分，共10分）1. 数字图像处理中，图像的灰度变换不包括以下哪一项？A. 对数变换B. 幂律变换C. 直方图均衡化D. 图像锐化答案：D2. 在数字图像处理中，边缘检测的目的是：A. 提取图像中的纹理信息B. 提取图像中的边缘信息C. 增强图像的对比度D. 改变图像的颜色分布答案：B3. 下列哪种滤波器用于平滑图像？A. 高通滤波器B. 低通滤波器C. 带通滤波器D. 带阻滤波器答案：B4. 在数字图像处理中，图像的几何变换不包括以下哪一项？B. 缩放C. 剪切D. 颜色变换答案：D5. 在数字图像处理中，以下哪种方法用于图像分割？A. 阈值处理B. 边缘检测C. 直方图分析D. 颜色量化答案：A二、多项选择题（每题3分，共15分）6. 数字图像处理中的图像增强技术包括：A. 直方图均衡化B. 锐化C. 噪声滤除D. 图像压缩答案：ABC7. 在数字图像处理中，以下哪些是空间域的图像增强方法？A. 直方图均衡化B. 中值滤波C. 拉普拉斯算子D. 傅里叶变换8. 数字图像处理中，以下哪些是频域的图像增强方法？A. 低通滤波B. 高通滤波C. 带通滤波D. 傅里叶变换答案：ABC9. 在数字图像处理中，以下哪些是图像的几何变换？A. 旋转B. 缩放C. 平移D. 颜色变换答案：ABC10. 数字图像处理中，以下哪些是图像分割的方法？A. 阈值处理B. 边缘检测C. 区域生长D. 颜色量化答案：ABC三、简答题（每题5分，共20分）11. 简述数字图像处理中边缘检测的基本原理。
答案：边缘检测的基本原理是识别图像中亮度变化剧烈的区域，这些区域通常对应于物体的边界。
通过应用边缘检测算子，如Sobel算子、Prewitt算子或Canny算子，可以突出图像中的边缘，从而为后续的图像分析和处理提供重要信息。
12. 描述数字图像处理中直方图均衡化的目的和效果。
答案：直方图均衡化的目的是改善图像的对比度，使图像的直方图分布更加均匀。
大学数字图像处理模拟考试题和答案解析
，（注：以下两套模拟题仅供题型参考，请重点关注选择填空以及判断题、名词解释，蓝色下划线内容肯定不考）《数字图像处理》模拟试卷（A 卷）一、单项选择题（从下列各题四个备选答案中选出一个正确答案，并将其代号填在题前的括号内。
答案选错或未作选择者，该题不得分。
每小题1分，共10分）( d )1.一幅灰度级均匀分布的图象，其灰度范围在[0，255]，则该图象的信息量为：a. 0( b )2.图象与灰度直方图间的对应关系是：a.一一对应b.多对一c.一对多d.都不对…( d )3.下列算法中属于局部处理的是：a.灰度线性变换b.二值化c.傅立叶变换d.中值滤波( b )4.下列算法中属于点处理的是：a.梯度锐化b.二值化c.傅立叶变换d.中值滤波( ) 5.一曲线的方向链码为12345，则曲线的长度为c )6. 下列算法中属于图象平滑处理的是：a.梯度锐化b.直方图均衡c. 中值滤波增强( )7.下列图象边缘检测算子中抗噪性能最好的是：￥a.梯度算子算子算子d. Laplacian算子( c)8.采用模板［-1 1］主要检测____方向的边缘。
a.水平° c.垂直°( d )9.二值图象中分支点的连接数为：( a )10.对一幅100´100像元的图象，若每像元用８bit表示其灰度值，经霍夫曼编码后压缩图象的数据量为40000bit，则图象的压缩比为：:1:1 :1:2二、填空题（每空1分，共15分））1.图像锐化除了在空间域进行外，也可在频率域进行。
2.图像处理中常用的两种邻域是4-邻域和8-邻域。
3.直方图修正法包括直方图均衡和直方图规定化两种方法。
4.常用的灰度差值法有最近邻元法、双线性内插法和三次内插法。
5.多年来建立了许多纹理分析法，这些方法大体可分为和结构分析法两大类。
6.低通滤波法是使高频成分受到抑制而让低频成分顺利通过，从而实现图像平滑。
7.检测边缘的Sobel算子对应的模板形式为和。
数字图像处理模拟题及参考答案
数字图像处理模拟题及参考答案电科08级数字图像处理模拟题及参考答案⼀、填空题1. ⼀般来说，对模拟图像数字化时采样间距越⼤，图像数据越少_,图像质量越_差_______ 2．若灰度图象每像素⽤8位表⽰，则灰度值可以取_0~255 包括0和255间的数值。
3. 在⼏何变换的3×3矩阵___________[p q]______________可以使图像实现平移变换4.⼆值形态学中，腐蚀运算的集合⽅式定义为____}|{XxSxSX?+=Θ____。
5.根据图像编码原理可以将图像编码分为_熵编码__、预测编码、__变换编码__和混合编码6. 图像与灰度直⽅图间的对应关系是_____多对⼀___7. 常⽤的灰度内插法有最近邻域法和 __双线性插值法_。
8.⼀幅图象的分辩率为512×512×8是指_图像的⾼和宽都为512像素，每个像素⽤8位表⽰,该图像⼤⼩约___2048KB9.检测边缘的Sobel算⼦对应的模板形式为_：-1 0 1 -2 0 2 -1 0 1 -1 -2 -10 0 01 2 110．分辩率是⽤来描述图象__清晰程度, ⼀幅图象的分辩率为512×512×8是指_图象宽和⾼都为512象素，每个象素⽤8位表⽰____, 电视摄象机的分辩率为480线是指__⼀副画⾯从上到下扫描⼀遍共有480⾏_________, 激光打印机分辩率为300dpi是指______每英⼨有300个点打印精度。
11.图象直⽅图表⽰：图像上各个灰度级上的像素数⽬。
灰度级01234567像素数33038984532121013.影像数字化包括抽样和量化两过程。
14.图象平滑既可在空间域中进⾏，也可在频率域中进⾏。
边缘检测算⼦对应的模板是：-1-1-1-101000-101111-10117.依据图象的保真度，图象编码可分为⽆失真（⽆损）编码和有失真（有损）编码两种。
18.图像处理中常⽤的两种邻域是 4-邻域和 8—邻域。
Digital Image Processing数字图像处理练习题
一、基本理论与方法1.简要归纳一下傅里叶变换在〈数学图像处理〉的各章节中都有哪些主要应用，应用了它的哪些性质或特点?对下面图像(checkerboard.tif)进行傅氏变换并平移到中心点.(注:先对图像进行灰度格式转换)1）1.图像增强与图像去噪：绝大部分噪音都是图像的高频分量，通过低通滤波器来滤除高频——噪声;边缘也是图像的高频分量，可以通过添加高频分量来增强原始图像的边缘；2.图像分割之边缘检测：提取图像高频分量3.图像特征提取：形状特征：傅里叶描述子纹理特征：直接通过傅里叶系数来计算纹理特征其他特征：将提取的特征值进行傅里叶变换来使特征具有平移、伸缩、旋转不变性4.图像压缩：可以直接通过傅里叶系数来压缩数据；常用的离散余弦变换是傅立叶变换的实变换；5.在图像分析和扫描中，用傅里叶子描述区域边界的二维坐标，在纹理分析中，可以用傅里叶颜谱的频率特性来描述周期的或者几乎周期的二维图像模式的方向性。
（2）步骤：i=imread('checkerboard.tif ');Di=double(i)/255;%将灰度值转成0-1之间的双精度值figure,imshow(Di);fi=fft2(Di);%离散傅氏正变换figure,imshow(fi);ifi=ifft2(fi);%反变换figure,imshow(ifi);变换后：2.先对下图进行二层小波变换(注:先将此图像变为索引图像)然后说明，在图像处理中小波变换的主要用途是什么?(1)小波变换在图像处理中的作用：小波变换没有频域变量，变换后的函数是尺度和位置参数的函数且仍在空域中，其结果是对原函数的位置和尺度的分解。
每一幅小波变换分解图是原函数在位移点的尺度放大或缩小。
是一个时间和频率的局域变换，因而能有效的从信号中提取信息，通过伸缩和平移等运算功能对函数或信号进行多尺度细化分析，解决了傅立叶变换不能解决的许多问题。
它的特点是压缩比高，压缩速度快，压缩后能保持信号与图像的特征不变，且在传递中可以抗干扰。
大学数字图像处理模拟考试题和答案解析
（注：以下两套模拟题仅供题型参考，请重点关注选择填空以及判断题、名词解释，蓝色下划线内容肯定不考）《数字图像处理》模拟试卷（A 卷）一、单项选择题（从下列各题四个备选答案中选出一个正确答案，并将其代号填在题前的括号内。
答案选错或未作选择者，该题不得分。
每小题1分，共10分）( d )1.一幅灰度级均匀分布的图象，其灰度范围在[0，255]，则该图象的信息量为：a. 0b.255c.6d.8( b )2.图象与灰度直方图间的对应关系是：a.一一对应b.多对一c.一对多d.都不对( d )3.下列算法中属于局部处理的是：a.灰度线性变换b.二值化c.傅立叶变换d.中值滤波( b )4.下列算法中属于点处理的是：a.梯度锐化b.二值化c.傅立叶变换d.中值滤波( ) 5.一曲线的方向链码为12345，则曲线的长度为a.5b.4c.5.83d.6.24( c )6. 下列算法中属于图象平滑处理的是：a.梯度锐化b.直方图均衡c. 中值滤波placian增强( )7.下列图象边缘检测算子中抗噪性能最好的是：a.梯度算子b.Prewitt算子c.Roberts算子d. Laplacian算子( c)8.采用模板［-1 1］主要检测____方向的边缘。
a.水平b.45°c.垂直d.135°( d )9.二值图象中分支点的连接数为：a.0b.1c.2d.3( a )10.对一幅100´100像元的图象，若每像元用８bit表示其灰度值，经霍夫曼编码后压缩图象的数据量为40000bit，则图象的压缩比为：a.2:1b.3:1c.4:1d.1:2二、填空题（每空1分，共15分）1.图像锐化除了在空间域进行外，也可在频率域进行。
2.图像处理中常用的两种邻域是4-邻域和8-邻域。
3.直方图修正法包括直方图均衡和直方图规定化两种方法。
4.常用的灰度差值法有最近邻元法、双线性内插法和三次内插法。
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Terms and concepts explanationRGB：Red Green Blue 三原色红绿蓝CMYK：cyan magenta yellow black 青、粉红、黄、黑HSI: hue saturation intensity 色调、饱和度、亮度FFT fast fourier transform 快速傅里叶变换CWT continuous wavelet transform 连续小波变换DCT discrete cosine transform 离散余弦变换DFT discrete fourier transform 离散傅里叶变换DWT discrete wavelet transform 离散小波变换CCD charge-coupled device电荷耦合元件Pixel a digital image is composed of a finite number of elements,each of which has a particular lication and value,these elements are called pixel 像素DC component in frequency domain （direct current component）直流分量的频率域GLH The Gray Level Histogram 灰度直方图Mather（basic）wavelet :a function (wave) used to generate a set of wavelets,母小波，用于产生小波变换所需的一序列子小波Basis functions basis image : there i s only one set of αk for any given f(x), then the ψk (x) are called basis functionsMulti-scale analysis多尺度分析Gaussian function:Gaussian function In mathematics,is a function of the form:for some real constants a 0, b, c 0, and e ≈ 2.718281828 (Euler’s number).对于一些真正的常量0,b,c 0,和e≈2.718281828(欧拉数)。
Sharpening filter ：锐化滤波器Smoothing filter/convolution ：smoothing filter are used for blurring and for noise reduction平滑滤波器用于模糊处理和降低噪声/卷积Imageenhancement/imagerestoration image Enhancement the process of manipulating an i mage so that the result is more suitable than the original for a specific application.图像增强处理是对图像进行的加工，使其结果对于特定的应用比原始图像更适合的一种处理。
Image restoration is an area that also deals with improving the appearance of an image. However, unlike enhancement, which is subjective, image restoration is objective.图像复原也是一个改进图像外观的一个处理领域，然而与图像增强不同，图像增强是主观的，图像复原是客观的。
取样sampling: Digitizing the coordinate values is called sampling.对坐标值进行数字化称为.. 量话quantization：Digitizing the amplitude values is called quantization.对幅值数字化称为.空间分辨率：spatial resolution is a measure of the smallest discernible detail in an image.图像中可辨别的最小细节的度量灰度分辨率：Intensity resolution refers to the smallest discernible change in intensity level.灰度分辨率是指在灰度级中可分辨的最小变化空间域滤波：Spatial domain filteringFrequency domain filtering：Frequency domain filtering with a variable frequency for the signal filtering 频率域滤波以频率作为变量对信号进行滤波wavelet transforms are based on small waves,of varying frequency and limited duration.小波变换基于一些小型波，它具有变化的频率和有限的持续时间。
Image compression,the art and science of reducing the amount of data required to represent an image.图像压缩是一种减少描绘一幅图像所需数据量的技术和科学.Cite one example of digital image processing？Answer: In the domain of medical image processing we may need to inspect a certain class of images generated by an electron microscope to eliminate bright, isolated dots that are no interest.Cite one example of spatial operation举一个空间操作的例子Answer:In the domain of medical image processing we may need to inspect a certain class of images generated by an electron microscope to eliminate bright, isolated dots that are no interest.From the following processing result make a general comment about ideal highpass(figure B)and Gaussian highpass filter(figure D)Answer：Gaussian highpass filter is more smooth than ideal highpass, even for small objects and thin lines with GHPF filter is also more clearThe original image, the ideal lowpass filter and Gaussian lowpass filter are shown be…B and C D and E are the results of the either filter B or Ca)Draw lines to connect the filters with their result 连线滤波器和处理结果b)Explain the difference of the two filters 解释两者的区别Answer：It is clear from this example that ideal lowpass filtering is not very practical实用,it has ringing properties. Over characteristics of Gauss filter is very flat, so it is not ringingBlurred with a 3x3 smoothing mask would the resultant histograms still be the same? Draw the two histograms and explain your answer 模糊了一个3x3的平滑的掩膜？会得到的直方图仍然是相同的吗？画两图并解释你的答案With the chromaticity diagram bellow give a brief description to the RGB color model. And these three colors enough to compose all visible colors?用色度图给出的RGB颜色模型的简短描述。
这三种颜色足以构成所有可见的颜色吗？Answer：Images represented in the RGB color model consist of three component images, one for each primary color.These three colors enough to compose all visible colorsWhat the result when applying an averaging mask with the size 1x1？什么样的结果时，应用平均掩膜大小1x1？不变A mean filter is a linear filter but a median filter is not. WHY？均值滤波器是一种线性滤波器，中值滤波器不是，为什么？The basic principle of linear filtering is to replace the original image with the mean value of each pixel, but median filter replace the original image with the median value of each pixel.The value of mean and median is different.Develop an algorithm which implements frequency domain filtering by means of Fourier transform. 利用傅立叶变换实现了频率域滤波的算法。