发布时间 : 星期日 文章数字图像处理模拟题（双语课）更新完毕开始阅读21f8e7fa58fafab068dc027f
Terms and concepts explanation RGB：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 is only one set of αk for any given f(x), then the
ψk (x) are called basis functions
Multi-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/imagerestorationimage 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 filtering
Frequency 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 clear
The 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 C
a) 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 ringing
Blurred 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 colors
What 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。
Answer：
The steps of the process are as follow:
(1) Multiply the input image f(x,y) by （-1）x+y to center the transform; （1）将输入图像f（x，y）的（-1）x+y为中心的变换；
(2) Compute the DFT of the image from (1) to get power spectrum F(u,v) of Fourier transform.
计算图像的DFT从（1）得到的功率谱f（u，v）的傅里叶变换。 Multiply by a filter function h(u,v) 乘以一个滤波器函数h(u,v) . Compute the inverse DFT of the result in (3). Obtain the real part of the result in (4). Multiply the result in (5) by（-1）x+y
The following matrix A is a 3x3 image and B is a 3x3 laplacian mask, what will be the resulting image?(Note that the elements beyond the border remain unchanged)
Develop an algorithm to obtain the processing result B from original image A
Develop an algorithm which computes the pseudo-color image by means of fourier transform Answer：
The steps of the process are as follow:
(1) Multiply the input image f(x,y) by （-1）x+y to center the transform;
(2) Compute the DFT of the image from (1) to get power spectrum F(u,v) of Fourier transform.
(3) Multiply by a filter function h(u,v) . (4) Compute the inverse DFT of the result in (3). (5) Obtain the real part of the result in (4). (6) Multiply the result in (5) by（-1）x+y （频率域的基本滤波步骤）