MATLAB图像处理函数汇总（一）

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)
siz =
64 50
相关命令:
blkproc
3.blkproc

MATLAB高级应用——图形及影像处理 320
功能: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 =
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,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 322
BW1 =[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 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] = bwlabel(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] = 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 324
imshow(BW1);
BW2 = bwmorph(BW1,'remove');
BW3 = bwmorph(BW1,'skel',Inf);
imshow(BW2)
figure, imshow(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 = 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] = 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, rgb2ind
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 = 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 328
10 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
55 149 117 163 159 135 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.
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, ifft2
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.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)
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)
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 332
[BW,threshold] = edge(I,'canny',...)
举例
I = imread('rice.tif');
BW1 = edge(I,'prewitt');
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
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)
举例
B = fftn(A);
C = fftshift(B);
相关命令:
fft2, fftn, ifftshift
31.filter2
功能:进行二维线性过滤操作.
语法:
B = filter2(h,A)
B = filter2(h,A,shape)
举例
A = magic(6)
A =
35 1 6 26 19 24
3 32 7 21 23 25
31 9 2 22 27 20
8 28 33 17 10 15
30 5 34 12 14 16
4 36 29 13 18 11
h = fspecial('sobel')
h =
1 2 1
0 0 0
-1 -2 -1
B = filter2(h,A,'valid')
B =
-8 4 4 -8
-23 -44 -5 40
-23 -50 1 40
-8 4 4 -8
相关命令:
conv2, roifilt2
32.freqspace
附录 MATLAB图像处理命令 335
功能:确定二维频率响应的频率空间.
语法:
[f1,f2] = freqspace(n)
[f1,f2] = freqspace([m n])
[x1,y1] = freqspace(...,'meshgrid')
f = freqspace(N)
f = freqspace(N,'whole')
相关命令:
fsamp2, fwind1, fwind2
33.freqz2
功能:计算二维频率响应.
语法:
[H,f1,f2] = freqz2(h,n1,n2)
[H,f1,f2] = freqz2(h,[n2 n1])
[H,f1,f2] = freqz2(h,f1,f2)
[H,f1,f2] = freqz2(h)
[...] = freqz2(h,...,[dx dy])
[...] = freqz2(h,...,dx)
freqz2(...)
举例
Hd = zeros(16,16);
Hd(5:12,5:12) = 1;
Hd(7:10,7:10) = 0;
h = fwind1(Hd,bartlett(16));
colormap(jet(64))
freqz2(h,[32 32]); axis ([-1 1 -1 1 0 1])
34.fsamp2
MATLAB高级应用——图形及影像处理 336
功能:用频率采样法设计二维FIR过滤器.
语法:
h = fsamp2(Hd)
h = fsamp2(f1,f2,Hd,[m n])
举例
[f1,f2] = freqspace(21,'meshgrid');
Hd = ones(21);
r = sqrt(f1.^2 + f2.^2);
Hd((r0.5)) = 0;
colormap(jet(64))
mesh(f1,f2,Hd)
相关命令:
conv2, filter2, freqspace, ftrans2, fwind1, fwind2
35.fspecial
功能:创建预定义过滤器.
语法:
h = fspecial(type)
h = fspecial(type,parameters)
举例
I = imread('saturn.tif');
h = fspecial('unsharp',0.5);
I2 = filter2(h,I)/255;
imshow(I)
figure, imshow(I2)
相关命令:
conv2, edge, filter2, fsamp2, fwind1, fwind2
36.ftrans2
功能:通过频率转换设计二维FIR过滤器.
语法:
附录 MATLAB图像处理命令 337
h = ftrans2(b,t)
h = ftrans2(b)
举例
colormap(jet(64))
b = remez(10,[0 0.05 0.15 0.55 0.65 1],[0 0 1 1 0 0]);
[H,w] = freqz(b,1,128,'whole');
plot(w/pi-1,fftshift(abs(H)))
相关命令:
conv2, filter2, fsamp2, fwind1, fwind2
37.fwind1
功能:用一维窗口方法设计二维FIR过滤器.
语法:
h = fwind1(Hd,win)
h = fwind1(Hd,win1,win2)
h = fwind1(f1,f2,Hd,...)
举例
[f1,f2] = freqspace(21,'meshgrid');
Hd = ones(21);
r = sqrt(f1.^2 + f2.^2);
Hd((r0.5)) = 0;
colormap(jet(64))
mesh(f1,f2,Hd)
相关命令:
conv2, filter2, fsamp2, freqspace, ftrans2, fwind2
38.fwind2
功能:用二维窗口方法设计二维FIR过滤器.
语法:
h = fwind2(Hd,win)
h = fwind2(f1,f2,Hd,win)
举例
[f1,f2] = freqspace(21,'meshgrid');
Hd = ones(21);
r = sqrt(f1.^2 + f2.^2);
Hd((r0.5)) = 0;
colormap(jet(64))
mesh(f1,f2,Hd)
MATLAB高级应用——图形及影像处理 338
相关命令:
conv2, filter2, fsamp2, freqspace, ftrans2, fwind1
39.getimage
功能:从坐标轴取得图像数据.
语法:
A = getimage(h)
[x,y,A] = getimage(h)
[...,A,flag] = getimage(h)
[...] = getimage
举例
imshow rice.tif
I = getimage;
40.gray2ind
功能:转换灰度图像为索引图像.
语法:
[X,map] = gray2ind(I,n)
相关命令:
ind2gray
41.grayslice
功能:从灰度图像创建索引图像.
语法:
X = grayslice(I,n)
X = grayslice(I,v)
举例
I = imread('ngc4024m.tif');
X = grayslice(I,16);
imshow(I)
figure, imshow(X,jet(16))
附录 MATLAB图像处理命令 339
相关命令:
gray2ind
42.histeq
功能:用柱状图均等化增强对比.
语法:
J = histeq(I,hgram)
J = histeq(I,n)
[J,T] = histeq(I,...)
举例
I = imread('tire.tif');
J = histeq(I);
imshow(I)
figure, imshow(J)
imhist(I,64)
figure; imhist(J,64)
相关命令:
brighten, imadjust, imhist
43.hsv2rgb
功能: 转换HSV值为RGB颜色空间.
语法:
rgbmap = hsv2rgb(hsvmap)
RGB = hsv2rgb(HSV)
相关命令:
MATLAB高级应用——图形及影像处理 340
rgb2hsv, rgbplot
44.idct2
功能:计算二维离散反余弦变换.
语法:
B = idct2(A)
B = idct2(A,m,n)
B = idct2(A,[m n])
相关命令:
dct2, dctmtx, fft2, ifft2
45.ifft2
功能:计算二维快速傅里叶反变换.
语法:
B = ifft2(A)
B = ifft2(A,m,n)
相关命令:
fft2, fftshift, idct2
46.ifftn
功能: 计算n维快速傅里叶反变换.
语法:
B = ifftn(A)
B = ifftn(A,siz)
相关命令:
fft2, fftn, ifft2
47.sim2bw
功能:转换图像为二进制图像.
语法:
BW = im2bw(I,level)
BW = im2bw(X,map,level)
BW = im2bw(RGB,level)
举例
load trees
BW = im2bw(X,map,0.4);
imshow(X,map)
附录 MATLAB图像处理命令 341
figure, imshow(BW)
相关命令:
ind2gray, rgb2gray
48.im2col
功能:重调图像块为列.
语法:
B = im2col(A,[m n],block_type)
B = im2col(A,[m n])
B = im2col(A,'indexed',...)
相关命令:
blkproc, col2im, colfilt, nlfilter
49.im2double
功能:转换图像矩阵为双精度型.
语法:
I2 = im2double(I1)
RGB2 = im2double(RGB1)
BW2 = im2double(BW1)
X2 = im2double(X1,'indexed')
相关命令:
double, im2uint8, uint8
50.im2uint8
功能:转换图像阵列为8位无符号整型.
语法:
I2 = im2uint8(I1)
RGB2 = im2uint8(RGB1)
BW2 = im2uint8(BW1)
X2 = im2uint8(X1,'indexed')
MATLAB高级应用——图形及影像处理 342
相关命令:
im2uint16, double, im2double, uint8, imapprox, uint16
51.im2uint16
功能:转换图像阵列为16位无符号整型.
语法:
I2 = im2uint16(I1)
RGB2 = im2uint16(RGB1)
X2 = im2uint16(X1,'indexed')
相关命令:
im2uint8, double, im2double, uint8, uint16, imapprox
52.imadjust
功能:调整图像灰度值或颜色映像表.
语法:
J = imadjust(I,[low high],[bottom top],gamma)
newmap = imadjust(map,[low high],[bottom top],gamma)
RGB2 = imadjust(RGB1,...)
举例
I = imread('pout.tif');
J = imadjust(I,[0.3 0.7],[]);
imshow(I)
figure, imshow(J)
相关命令:
brighten, histeq
53.imapprox
功能:对索引图像进行近似处理.
语法:
[Y,newmap] = imapprox(X,map,n)
附录 MATLAB图像处理命令 343
[Y,newmap] = imapprox(X,map,tol)
Y = imapprox(X,map,newmap)
[...] = imapprox(...,dither_option)
相关命令:
cmunique, dither, rgb2ind
54.imcontour
功能:创建图像数据的轮廓图.
语法:
imcontour(I,n)
imcontour(I,v)
imcontour(x,y,...)
imcontour(...,LineSpec)
[C,h] = imcontour(...)
举例
I = imread('ic.tif');
imcontour(I,3)
相关命令:
clabel, contour, LineSpec
55.imcrop
功能:剪切图像.
语法:
I2 = imcrop(I)
X2 = imcrop(X,map)
RGB2 = imcrop(RGB)
I2 = imcrop(I,rect)
X2 = imcrop(X,map,rect)
RGB2 = imcrop(RGB,rect)
MATLAB高级应用——图形及影像处理 344
[...] = imcrop(x,y,...)
[A,rect] = imcrop(...)
[x,y,A,rect] = imcrop(...)
举例
I = imread('ic.tif');
I2 = imcrop(I,[60 40 100 90]);
imshow(I)
figure, imshow(I2)
相关命令:
zoom
56.imfeature
功能:计算图像区域的特征尺寸.
语法:
stats = imfeature(L,measurements)
stats = imfeature(L,measurements,n)
举例
BW = imread('text.tif');
L = bwlabel(BW);
stats = imfeature(L,'all');
stats(23)
ans =
Area: 89
Centroid: [95.6742 192.9775]
BoundingBox: [87.5000 184.5000 16 15]
MajorAxisLength: 19.9127
MinorAxisLength: 14.2953
Eccentricity: 0.6961
Orientation: 9.0845
ConvexHull: [28x2 double]
附录 MATLAB图像处理命令 345
ConvexImage: [15x16 uint8 ]
ConvexArea: 205
Image: [15x16 uint8 ]
FilledImage: [15x16 uint8 ]
FilledArea: 122
EulerNumber: 0
Extrema: [ 8x2 double]
EquivDiameter: 10.6451
Solidity: 0.4341
Extent: 0.3708
PixelList: [89x2 double]
相关命令:
bwlabel
57.imfinfo
功能:返回图形文件信息.
语法:
info = imfinfo(filename,fmt)
info = imfinfo(filename)
举例
info = imfinfo('canoe.tif')
info =
Filename:'canoe.tif'
FileModDate: '25-Oct-1996 22:10:39'
FileSize: 69708
Format: 'tif'
FormatVersion: []
Width: 346
Height: 207
BitDepth: 8
ColorType: 'indexed'
FormatSignature: [73 73 42 0]
ByteOrder: 'little-endian'
NewSubfileType: 0
BitsPerSample: 8
Compression: 'PackBits'
PhotometricInterpretation: 'RGB Palette'
MATLAB高级应用——图形及影像处理 346
StripOffsets: [ 9x1 double]
SamplesPerPixel: 1
RowsPerStrip: 23
StripByteCounts: [ 9x1 double]
XResolution: 72
YResolution: 72
ResolutionUnit: 'Inch'
Colormap: [256x3 double]
PlanarConfiguration: 'Chunky'
TileWidth: []
TileLength: []
TileOffsets: []
TileByteCounts: []
Orientation: 1
FillOrder: 1
GrayResponseUnit: 0.0100
MaxSamplue: 255
MinSamplue: 0
Thresholding: 1
相关命令:
imread, imwrite
58.imhist
功能:显示图像数据的柱状图.
语法:
imhist(I,n)
imhist(X,map)
[counts,x] = imhist(...)
举例
I = imread('pout.tif');
imhist(I)
附录 MATLAB图像处理命令 347
相关命令:
histeq
59.immovie
功能:创建多帧索引图的电影动画.
语法:
mov = immovie(X,map)
举例
load mri
mov = immovie(D,map);
相关命令:
montage

感谢：http://blog.sina.com.cn/s/blog_45b486b80100g46y.html