数字图像处理灰度变换

1、实验一1.对一幅图像进行二值化处理load trees;BW=im2bw(X,map,0.4;imshow(X,map;figure,imshow(BW; 2.将一幅索引色图转化成灰度图像close all;clear all;load trees;I=ind2gray(X,map;imshow(X,map;figure,imshow(I 3.将一幅灰度图转化成索引色图像close all;clear all;I=imread('moon.tif'X=grayslice(I,16;imshow(Ifigure,imshow(X,hot(16 4.显示一彩色图像的三基色图像foo

2、tball=imread('football.jpg'figure('Name','Football'imshow(football;figure('Name','Football color planes'subplot(2,2,1;imshow(football;redfootball=football;redfootball(:,:,2:3=0;subplot(2,2,2;imshow(redfootball;greenfootball=football;greenfootball(:,:,1=0;green

3、football(:,:,3=0;subplot(2,2,3;imshow(greenfootball;bluefootball=football;bluefootball(:,:,1:2=0;subplot(2,2,4;imshow(bluefootball; 实验五编写lowpassfilter.m和highpassfilrer.m,保存在work文件夹中%cutoff is the cutoff frequency of the filter 0 - 0.5 function f=highpassfilter(sze,cutoff,nif cutoff<0 | cutoff>

4、0.5error('cutoff frequency must be between 0 and 0.5' endif rem(n,1=0 | n<1error('n must be an integer>=1'endS=size(sze;rows=S(1;cols=S(2;x=(ones(rows,1*1:cols-(fix(cols/2+1/cols;y=(1:rows'*ones(1,cols-(fix(rows/2+1/rows;radius=sqrt(x.2+y.2;h1=1./(1.0+(radius./cutoff.(2*n;h

5、=ones(rows,cols-h1;plot3(x,y,h;title('Butterworth高通滤波器幅频响应'B=fftshift(fft2(sze;result=ifft2(B.*h;figure,imshow(abs(result,;title('高通滤波后的图像'(1I=imread('cameraman.tif'lowpassfilter(I,0.4,1;I=imread('cameraman.tif' lowpassfilter(I,0.05,1; -0.5 0.5低通滤波后的图像(2I=imread('

6、cameraman.tif' highpassfilter(I,0.4,1; -0.5 0.5低通滤波后的图像I=imread('cameraman.tif' highpassfilter(I,0.05,1; -0.5 0.5高通滤波后的图像2.分别采用Hamming 窗,Bartlett 窗,Hanning 窗和Blackman 窗设计近似圆对称的带通滤波器,通频带为【0.1,0.5】。%创建期望的频率响应矩阵Hd f1,f2=freqspace(21,'meshgrid' Hd=ones(21; r=sqrt(f1.2+f2.2;-0.5 0.5高通

7、滤波后的图像Hd(r<0.1|(r>0.5=0; colormap(jet(64 mesh(f1,f2,Hd;h1=fwind1(Hd,hamming(21; figure,freqz2(h1;h2=fwind1(Hd,bartlett(21; figure,freqz2(h2;h3=fwind1(Hd,hanning(21; figure,freqz2(h3;h4=fwind1(Hd,blackman(21; figure,freqz2(h4; 期望的频率响应矩阵Hd -11-1 1F xF yM a g n i t u d e-1 1F xF yM a g n i t u d e3.用二维高斯窗设计近似圆对称的高通滤波器 close all; clear all;-1 1F xF yM a g n i t u d e-1 1F xF yM a g n i t u d e%创建期望的频率响应矩阵Hd f1,f2=freqspace(21,'meshgrid' Hd=ones(21; r=sqrt(f1.2+f2.2; Hd(r<0.5=0; colormap(jet(64 mesh(f1,f2,Hd;win=fspecial('ga