1、1.applylut 功能: 在二进制图像中利用 lookup 表进行边沿操作. 语法: A = applylut(BW,lut) 举例 lut = makelut(sum(x(:) = 4,2); BW1 = imread(text.tif); BW2 = applylut(BW1,lut); imshow(BW1) figure, imshow(BW2) 相关命令: makelut 2.bestblk 功能: 确定进行块操作的块大小. 语法: siz = bestblk(m n,k) mb,nb = bestblk(m n,k) 举例 siz = bestblk(640 800,72) s
2、iz = 64 50 相关命令: blkproc 3.blkproc 功能: MATLAB 高级应用图形及影像处理 320实现图像的显式块操作. 语法: B = blkproc(A,m n,fun) B = blkproc(A,m n,fun,P1,P2,.) B = blkproc(A,m n,mborder nborder,fun,.) B = blkproc(A,indexed,.) 举例 I = imread(alumgrns.tif); I2 = blkproc(I,8 8,std2(x)*ones(size(x); imshow(I) figure, imshow(I2,); 相关
3、命令: colfilt, nlfilter,inline 4.brighten 功能: 增加或降低颜色映像表的亮度. 语法: brighten(beta) newmap = brighten(beta) newmap = brighten(map,beta) brighten(fig,beta) 相关命令: imadjust, rgbplot 5.bwarea 功能: 计算二进制图像对象的面积. 语法: total = bwarea(BW) 举例 BW = imread(circles.tif); imshow(BW); 附录 MATLAB 图像处理命令 321 bwarea(BW) ans
4、= 15799 相关命令: bweuler, bwperim 6.bweuler. 功能: 计算二进制图像的欧拉数. 语法: eul = bweuler(BW,n) 举例 BW = imread(circles.tif); imshow(BW); bweuler(BW) ans = -2 相关命令: bwmorph, bwperim 7.bwfill 功能: 填充二进制图像的背景色. 语法: BW2 = bwfill(BW1,c,r,n) BW2 = bwfill(BW1,n) BW2,idx = bwfill(.) BW2 = bwfill(x,y,BW1,xi,yi,n) x,y,BW2,
5、idx,xi,yi = bwfill(.) BW2 = bwfill(BW1,holes,n) BW2,idx = bwfill(BW1,holes,n) 举例 MATLAB 高级应用图形及影像处理 322BW1 =1 0 0 0 0 0 0 0 1 1 1 1 1 0 0 0 1 0 0 0 1 0 1 0 1 0 0 0 1 1 1 0 1 1 1 1 0 1 1 1 1 0 0 1 1 0 1 0 1 0 0 0 1 0 1 0 1 0 0 0 1 1 1 0 BW2 = bwfill(BW1,3,3,8) BW2 = 1 0 0 0 0 0 0 0 1 1 1 1 1 0 0 0 1
6、1 1 1 1 0 1 0 1 1 1 1 1 1 1 0 1 1 1 1 0 1 1 1 1 0 0 1 1 0 1 0 1 0 0 0 1 0 1 0 1 0 0 0 1 1 1 0 I = imread(blood1.tif); BW3 = im2bw(I); BW4 = bwfill(BW3,holes); imshow(BW3) figure, imshow(BW4) 相关命令: bwselect, roifill 8.bwlabel 功能: 标注二进制图像中已连接的部分. 语法: 附录 MATLAB 图像处理命令 323 L = bwlabel(BW,n) L,num = bwla
7、bel(BW,n) 举例 BW = 1 1 1 0 0 0 0 0 1 1 1 0 1 1 0 0 1 1 1 0 1 1 0 0 1 1 1 0 0 0 1 0 1 1 1 0 0 0 1 0 1 1 1 0 0 0 1 0 1 1 1 0 0 1 1 0 1 1 1 0 0 0 0 0 L = bwlabel(BW,4) L = 1 1 1 0 0 0 0 0 1 1 1 0 2 2 0 0 1 1 1 0 2 2 0 0 1 1 1 0 0 0 3 0 1 1 1 0 0 0 3 0 1 1 1 0 0 0 3 0 1 1 1 0 0 3 3 0 1 1 1 0 0 0 0 0 r,c
8、= find(L=2); rc = r c rc = 2 5 3 5 2 6 3 6 相关命令: bweuler, bwselect 9.bwmorph 功能: 提取二进制图像的轮廓. 语法: BW2 = bwmorph(BW1,operation) BW2 = bwmorph(BW1,operation,n) 举例 BW1 = imread(circles.tif); MATLAB 高级应用图形及影像处理 324imshow(BW1); BW2 = bwmorph(BW1,remove); BW3 = bwmorph(BW1,skel,Inf); imshow(BW2) figure, im
9、show(BW3) 相关命令: bweuler, bwperim, dilate, erode 10.bwperim 功能: 计算二进制图像中对象的周长. 语法: BW2 = bwperim(BW1,n) 举例 BW1 = imread(circbw.tif); BW2 = bwperim(BW1,8); imshow(BW1) figure, imshow(BW2) 附录 MATLAB 图像处理命令 325 相关命令: bwarea, bweuler, bwfill 11.bwselect 功能: 在二进制图像中选择对象. 语法: BW2 = bwselect(BW1,c,r,n) BW2
10、= bwselect(BW1,n) BW2,idx = bwselect(.) 举例 BW1 = imread(text.tif); c = 16 90 144; r = 85 197 247; BW2 = bwselect(BW1,c,r,4); imshow(BW1) figure, imshow(BW2) 相关命令: bwfill, bwlabel, impixel, roipoly, roifill 12.cmpermute MATLAB 高级应用图形及影像处理 326功能: 调整颜色映像表中的颜色. 语法: Y,newmap = cmpermute(X,map) Y,newmap =
11、 cmpermute(X,map,index) 举例 To order a colormap by luminance, use: ntsc = rgb2ntsc(map); dum,index = sort(ntsc(:,1); Y,newmap = cmpermute(X,map,index); 相关命令: randperm 13.cmunique 功能: 查找颜色映像表中特定的颜色及相应的图像. 语法: Y,newmap = cmunique(X,map) Y,newmap = cmunique(RGB) Y,newmap = cmunique(I) 相关命令: gray2ind, rg
12、b2ind 14.col2im 功能: 将矩阵的列重新组织到块中. 语法: A = col2im(B,m n,mm nn,block_type) A = col2im(B,m n,mm nn) 相关命令: blkproc, colfilt, im2col, nlfilter 15.colfilt 功能: 利用列相关函数进行边沿操作. 语法: B = colfilt(A,m n,block_type,fun) B = colfilt(A,m n,block_type,fun,P1,P2,.) B = colfilt(A,m n,mblock nblock,block_type,fun,.) B
13、= colfilt(A,indexed,.) 附录 MATLAB 图像处理命令 327 相关命令: blkproc, col2im, im2col, nlfilter 16.colorbar 功能: 显示颜色条. 语法: colorbar(vert) colorbar(horiz) colorbar(h) colorbar h = colorbar(.) 举例 I = imread(blood1.tif); h = fspecial(log); I2 = filter2(h,I); imshow(I2,), colormap(jet(64), colorbar 17.conv2 功能: 进行二
14、维卷积操作. 语法: C = conv2(A,B) C = conv2(hcol,hrow,A) C = conv2(.,shape) 举例 A = magic(5) A = 17 24 1 8 15 23 5 7 14 16 4 6 13 20 22 MATLAB 高级应用图形及影像处理 32810 12 19 21 3 11 18 25 2 9 B = 1 2 1;0 2 0;3 1 3 B = 1 2 1 0 2 0 3 1 3 C = conv2(A,B) C = 17 58 66 34 32 38 15 23 85 88 35 67 76 16 55 149 117 163 159
15、135 67 79 78 160 161 187 129 51 23 82 153 199 205 108 75 30 68 135 168 91 84 9 33 65 126 85 104 15 27 相关命令: filter2 18.convmtx2 功能: 计算二维卷积矩阵. 语法: T = convmtx2(H,m,n) T = convmtx2(H,m n) 相关命令: conv2 19.convn 功能: 计算 n 维卷积 . 语法: C = convn(A,B) C = convn(A,B,shape) 相关命令: conv2 20.corr2 功能: 计算两个矩阵的二维相关系数
16、. 附录 MATLAB 图像处理命令 329 语法: r = corr2(A,B) 相关命令: std2 21.dct2 功能: 进行二维离散余弦变换. 语法: B = dct2(A) B = dct2(A,m,n) B = dct2(A,m n) 举例 RGB = imread(autumn.tif); I = rgb2gray(RGB); J = dct2(I); imshow(log(abs(J),), colormap(jet(64), colorbar J(abs(J) 10) = 0; K = idct2(J)/255; imshow(K) 相关命令: fft2, idct2, i
17、fft2 22.dctmtx 功能: MATLAB 高级应用图形及影像处理 330计算离散余弦变换矩阵. 语法: D = dctmtx(n) 相关命令: dct2 23.dilate 功能: 放大二进制图像. 语法: BW2 = dilate(BW1,SE) BW2 = dilate(BW1,SE,alg) BW2 = dilate(BW1,SE,.,n) 举例 BW1 = imread(text.tif); SE = ones(6,2); BW2 = dilate(BW1,SE); imshow(BW1) figure, imshow(BW2) 相关命令: bwmorph, erode 24
18、.dither 功能: 通过抖动增加外观颜色分辨率,转换图像. 语法: X = dither(RGB,map) BW = dither(I) 相关命令: rgb2ind 25.double 附录 MATLAB 图像处理命令 331 功能: 转换数据为双精度型. 语法: B = double(A) 举例 A = imread(saturn.tif); B = sqrt(double(A); 相关命令: im2double, im2uint, uint8 26.edge 功能: 识别强度图像中的边界. 语法: BW = edge(I,sobel) BW = edge(I,sobel,thresh)
19、 BW = edge(I,sobel,thresh,direction) BW,thresh = edge(I,sobel,.) BW = edge(I,prewitt) BW = edge(I,prewitt,thresh) BW = edge(I,prewitt,thresh,direction) BW,thresh = edge(I,prewitt,.) BW = edge(I,roberts) BW = edge(I,roberts,thresh) BW,thresh = edge(I,roberts,.) BW = edge(I,log) BW = edge(I,log,thresh
20、) BW = edge(I,log,thresh,sigma) BW,threshold = edge(I,log,.) BW = edge(I,zerocross,thresh,h) BW,thresh = edge(I,zerocross,.) BW = edge(I,canny) BW = edge(I,canny,thresh) BW = edge(I,canny,thresh,sigma) MATLAB 高级应用图形及影像处理 332BW,threshold = edge(I,canny,.) 举例 I = imread(rice.tif); BW1 = edge(I,prewitt
21、); BW2 = edge(I,canny); imshow(BW1); figure, imshow(BW2) 27.erode 功能: 弱化二进制图像的边界. 语法: BW2 = erode(BW1,SE) BW2 = erode(BW1,SE,alg) BW2 = erode(BW1,SE,.,n) 举例 BW1 = imread(text.tif); SE = ones(3,1); BW2 = erode(BW1,SE); imshow(BW1) figure, imshow(BW2) 相关命令: bwmorph, dilate 附录 MATLAB 图像处理命令 333 28.fft2
22、 功能: 进行二维快速傅里叶变换. 语法: B = fft2(A) B = fft2(A,m,n) 举例 load imdemos saturn2 imshow(saturn2) B = fftshift(fft2(saturn2); imshow(log(abs(B),), colormap(jet(64), colorbar 相关命令: dct2, fftshift, idct2, ifft2 29.fftn 功能: 进行 n 维快速傅里叶变换. 语法: B = fftn(A) B = fftn(A,siz) 相关命令: fft2, ifftn 30.fftshift MATLAB 高级应用图形及影像处理 334功能: 把快速傅里叶变换的 DC 组件移到光谱中心. 语法: B = fftshift(A)
