ztong上机3

二、实验名称：数字图像处理matlab上机

三、实验学时：2学时

四、实验目的：（详细填写）

• 掌握几何变换
• 掌握插值
• 理解配准的概念

五．实验内容

• （1）首先自己写一个对图像进行旋转和缩放的复合变换程序；
• （2）然后通过基于点的配准找到一个变换矩阵，以将前面变换后的图像再变换回去。

六、实验器材（设备、元器件）：

硬件：计算机 软件：windows XP ,matlab7.0

七、实验数据及结果分析：

内容一程序：

   1:  

   2: function out = LinearT( 

   3: In,theta,sx, sy) 

   4: im 

   5: = imread(In); 

   6: degree = theta; 

   7: imm = im2double(im); 

   8: cos_d = cos(degree); 

   9: sin_d = sin(degree);  

  10: [width, height] = size(im);  

  11: R 

  12: = [cos_d -sin_d 0 

  13: sin_d cos_d 0 

  14: 0 

  15: 0 1]; 

  16: T 

  17: = [1 0 -width/2.0 

  18: 0 

  19: 1 -height/2.0 

  20: 0 

  21: 0 1]; 

  22: S=[sx,0,0; 

  23: 0,sy,0; 

  24: 0,0,1];  

  25: R=inv(T)*S*R*T;  

  26: [W, H, ws, we, hs, he] = 

  27: ComputeOutImSize(im, R); 

  28:  

  29: inR = inv(R); 

  30: ii=0; 

  31:  

  32: for i = ws:we%row 

  33: ii=ii+1; jj=0; 

  34: for j = hs:he%col 

  35: jj=jj+1; 

  36: locate_r = [i j 1]'; 

  37: locate_s = inR*locate_r; 

  38: if(((locate_s(1)<=1)||(locate_s(1)>=width))||((locate_s(2)<=1)||(locate_s(2)>=height))) 

  39: V(ii,jj) = 0; 

  40: else 

  41: V(ii,jj) = 

  42: BilinearInterplate(imm,locate_s); 

  43:  

  44: end 

  45: end 

  46: end 

  47:  

  48: out= im2uint8(V); 

  49: end 

  50:  

  51: 调用程序 

  52: In='pre.bmp'; 

  53:  

  54: theta=pi/8; 

  55: sx=2; 

  56:  

  57: sy=4; 

  58:  

  59: out = LinearT( In,theta,sx, 

  60: sy); 

  61: imshow(out) 

  62:  

原始图像

处理后的图像

内容二程序

   1:  

   2: s=1; 

   3:  

   4: f1=imread('pre.bmp'); 

   5:  

   6: f2=imread('flop.bmp'); 

   7:  

   8: figure(1) 

   9: subplot(121),imshow(f1) 

  10: subplot(122),imshow(f2) 

  11: N=4; 

  12: imtool(f2) 

  13: [w1,h1]=size(f1); 

  14: [w2,h2]=size(f2); 

  15: a=[0 0]';b=[w1-1 0]';c=[0 h1-1]';d=[w1-1 

  16: h1-1]'; 

  17: a1=[4 93]';b1=[224 1]';c1=[113 

  18: 359]';d1=[333 267]'; 

  19: x=[a b c d]; 

  20: y=[a1 b1 c1 d1]; 

  21: H=zeros(2); 

  22: xmean=[sum(x(1,:))/N;sum(x(2,:))/N]; 

  23:  

  24: ymean=[sum(y(1,:))/N;sum(y(2,:))/N]; 

  25:  

  26: xx=[x(1,:)-xmean(1);x(2,:)-xmean(2)]; 

  27:  

  28: yy=[y(1,:)-ymean(1);y(2,:)-ymean(2)]; 

  29:  

  30: for i=1:N 

  31: H=H+xx(:,i)*(yy(:,i))'; 

  32: end 

  33: [U,S,V]=svd(H); 

  34: r=det(U*V); 

  35: W=[1 0;0 r]; 

  36: R=V*W*U'; 

  37: s=0; 

  38:  

  39: for i=1:N 

  40: s1=s+R*xx(:,i).*yy(:,i); 

  41: end 

  42:  

  43: for i=1:N 

  44: s2=s+R*xx(:,i).*xx(:,i); 

  45: end 

  46:  

  47: s=s1/s2; 

  48: t=xmean-s*R*ymean; 

  49: imm=im2double(f2); 

  50: ii=0; 

  51: for i 

  52: =1:w1 

  53: ii=ii+1; jj=0; 

  54: for j = 

  55: 1:h1 

  56: jj=jj+1; 

  57: SS=inv(R)*([i j]'-t); 

  58: if(((SS(1)<=1)||(SS(1)>=w2))||((SS(2)<=1)||(SS(2)>=h2))) 

  59:  

  60: S(ii,jj) = 0; 

  61: else 

  62: S(ii,jj) = BilinearInterplate(imm,SS); 

  63:  

  64: end 

  65: end 

  66:  

  67: end 

  68:  

  69: S0= 

  70: im2uint8(S); 

  71: figure(2) 

  72: imshow(S0) 

  73:  

八、总结及心得体会：

• 掌握了几何变换
• 掌握了插值
• 理解了配准的概念

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