本文系《数字图像处理原理与实践（MATLAB版）》一书之代码系列的Part2（P43~80），代码执行结果请参见原书配图，建议下载代码前阅读下文：
关于《数字图像处理原理与实践（MATLAB版）》一书代码发布的说明
http://blog.csdn.net/baimafujinji/article/details/40987807
P44
i = imread(‘theatre.jpg‘);
i = rgb2gray(i);
i = double(i);
out1 = log(1+i)/0.065;
out2 = log(1+i)/0.035;
out1(find(out1>255)) = 255;
out2(find(out2>255)) = 255;
out1 = uint8(out1);
out2 = uint8(out2);
subplot(221), imshow(out1), title(‘image, p = 0.065‘);
subplot(222), imhist(out1), title(‘histgram, p = 0.065‘);
subplot(223), imshow(out2), title(‘image, p = 0.035‘);
subplot(224), imhist(out2), title(‘histgram, p = 0.035‘);
P47
i = rgb2gray(imread(‘theatre.jpg‘));
i = double(i);
y1 = 255*(i/255).^2.5;
y2 = 255*(i/255).^0.4;
y1 = uint8(y1);
y2 = uint8(y2);
subplot(221), imshow(y1), title(‘p =2.5‘);
subplot(222), imhist(y1), title(‘p =2.5‘);
subplot(223), imshow(y2), title(‘p =0.4‘);
subplot(224), imhist(y2), title(‘p =0.4‘);
P48
i = rgb2gray(imread(‘theatre.jpg‘));
y1 = double(i);
y1 = 255*(y1/255).^2.5;
y2 = uint8(y1);
y3 = imadjust(y2, [ ], [ ], 0.4);
subplot(131), imshow(i), title(‘original image‘);
subplot(132), imshow(y2),title(‘power = 2.5‘);
subplot(133), imshow(y3),title(‘gamma = 0.4‘);
P49
i = imread(‘theatre.jpg‘);
i = rgb2gray(i);
i = double(i);
y1 = 1.5.^(i*0.070)-1;
y2 = 1.5.^(i*0.050)-1;
y1(find(y1>255)) = 255;
y2(find(y2>255)) = 255;
y1 = uint8(y1);
y2 = uint8(y2);
subplot(221), imshow(y1), title(‘c=0.070‘);
subplot(222), imhist(y1), title(‘c=0.070‘);
subplot(223), imshow(y2), title(‘c=0.050‘);
subplot(224), imhist(y2), title(‘c=0.050‘);
P52
i = imread(‘theatre.jpg‘);
i = rgb2gray(i);
L = imadjust(i,[ ],[50/255;150/255]);
J = imadjust(L,[50/255;150/255 ],[20/255;230/255]);
subplot(221), imshow(L), title(‘low contrast‘);
subplot(222), imhist(L), title(‘low contrast‘);
subplot(223), imshow(J), title(‘gray stretch‘);
subplot(224), imhist(J), title(‘gray stretch‘);
P54
i = rgb2gray(imread(‘theatre.jpg‘));
LC = imadjust(i,[ ],[50/255;150/255]);
figure(1), subplot(221), imshow(LC);
title(‘low contrast‘);
figure(1),subplot(222), imhist(LC);
title(‘low contrast‘);
HE1 = histeq(LC);
figure(1), subplot(223), imshow(HE1);
title(‘histogram equalization‘);
figure(1),subplot(224), imhist(HE1);
title(‘histogram equalization‘);
P56
img = rgb2gray(imread(‘theatre.jpg‘));
img_ref = rgb2gray(imread(‘rpic.jpg‘));
[hgram, x] = imhist(img_ref);
J = histeq(img, hgram);
subplot(2,3,1), imshow(img), title(‘original image‘);
subplot(2,3,4), imhist(img), title(‘original image‘);
subplot(2,3,2), imshow(img_ref), title(‘reference image‘);
subplot(2,3,5), imhist(img_ref), title(‘reference image‘);
subplot(2,3,3), imshow(J), title(‘output image‘);
subplot(2,3,6), imhist(J), title(‘output image‘);
P64-1
I = imread(‘apostles.jpg‘);
I = double(I);
B = zeros(size(I));
H = size(I);
move_x = 100;
move_y = 150;
B(move_y + 1:H(1), move_x+1:H(2), 1:H(3))=...
I(1:H(1)-move_y, 1:H(2) - move_x, 1:H(3));
subplot(1,2,1),subimage(uint8(I))
title(‘原图像‘)
subplot(1,2,2),subimage(uint8(B))
title(‘平移变换‘);
P64-2
I = imread(‘apostles.jpg‘);
se=translate(strel(1),[150 100]);
B = imdilate(I,se);
figure;
subplot(1,2,1),subimage(I);
title(‘原图像‘);
subplot(1,2,2),subimage(B);
title(‘平移变换‘);
P66
I = imread(‘apostles.jpg‘);
[height, width, dim]=size(I);
%水平镜像变换
tform = maketform(‘affine‘,[-1 0 0;0 1 0; width 0 1]);
B=imtransform(I, tform, ‘nearest‘);
%垂直镜像变换
tform2 = maketform(‘affine‘, [1 0 0; 0 -1 0; 0 height 1]);
C=imtransform(I, tform2, ‘nearest‘);
subplot(1,3,1),imshow(I);
title(‘原图像‘);
subplot(1,3,2),imshow(B);
title(‘水平图像‘);
subplot(1,3,3),imshow(C);
title(‘垂直图像‘);
P67
A = imread(‘apostles.jpg‘);
A = double(A);
figure(1), imshow(uint8(A));
H = size(A);
figure(2),B(1:H(1),1:H(2),1:H(3))=A(H(1):-1:1,1:H(2),1:H(3));%垂直镜像
imshow(uint8(B));
figure(3),C(1:H(1),1:H(2),1:H(3))=A(1:H(1),H(2):-1:1,1:H(3));%水平镜像
imshow(uint8(C));
P69
I = imread(‘apostles.jpg‘);
tform = maketform(‘affine‘,[0 1 0; 1 0 0; 0 0 1]);%定义转置矩阵
B = imtransform(I, tform, ‘nearest‘);
subplot(1,2,1),imshow(I)
title(‘原图像‘);
subplot(1,2,2),imshow(B)
title(‘转置图像‘);
P74
I = imread(‘C:\apostles.jpg‘);
A = imresize(I, 1.5, ‘nearest‘);
B = imresize(I, 1.5, ‘bilinear‘);
C = imresize(I, 1.5, ‘bicubic‘);
subplot(2,2,1), imshow(I), title(‘original‘);
subplot(2,2,2), imshow(A), title(‘nearest‘);
subplot(2,2,3), imshow(B), title(‘bilinear‘);
subplot(2,2,4), imshow(C), title(‘bicubic‘);
P80
I = imread(‘apostles.jpg‘);
A = imrotate(I, 30, ‘nearest‘);%旋转30度,最邻近插值
figure(1),imshow(A)
B = imrotate(I, 45, ‘bilinear‘,‘loose‘);%旋转45度，二次线性插值
figure(2),imshow(B)