MATLAB图像处理函数汇总（二)

60.imnoise

功能:增加图像的渲染效果.

语法:

J = imnoise(I,type)

J = imnoise(I,type,parameters)

举例

I = imread('eight.tif');

J = imnoise(I,'salt & pepper',0.02);

imshow(I)

figure, imshow(J)

相关命令:

rand

61.impixel

功能:确定像素颜色值.

语法:

MATLAB高级应用——图形及影像处理 348

P = impixel(I)

P = impixel(X,map)

P = impixel(RGB)

P = impixel(Incur)

P = impixel(X,map,c,r)

P = impixel(RGB,c,r)

[carp] = impixel(...)

P = impixel(x,y,I,xi,yi)

P = impixel(x,y,X,map,xi,yi)

P = impixel(x,y,RGB,xi,yi)

[xi,yi,P] = impixel(x,y,...)

举例

RGB = imread('flowers.tif');

c = [12 146 410];

r = [104 156 129];

pixels = impixel(RGB,c,r)

pixels =

61 59 101

253 240 0

237 37 44

相关命令:

improfile, pixval

62.improfile

功能:沿线段计算剖面图的像素值.

语法:

c = improfile

c = improfile(n)

c = improfile(I,xi,yi)

c = improfile(I,xi,yi,n)

[cx,cy,c] = improfile(...)

[cx,cy,c,xi,yi] = improfile(...)

[...] = improfile(x,y,I,xi,yi)

[...] = improfile(x,y,I,xi,yi,n)

附录 MATLAB图像处理命令 349

[...] = improfile(...,method)

举例

I = imread('alumgrns.tif');

x = [35 338 346 103];

y = [253 250 17 148];

improfile(I,x,y), grid on

相关命令:

impixel, pixval

63.imread

功能:从图形文件中读取图像.

语法:

A = imread(filename,fmt)

[X,map] = imread(filename,fmt)

[...] = imread(filename)

[...] = imread(...,idx) (TIFF only)

[...] = imread(...,ref) (HDF only)

[...] = imread(...,'BackgroundColor',BG) (PNG only)

[A,map,alpha] = imread(...) (PNG only)

举例

[X,map] = imread('flowers.tif',6);

info = imfinfo('skull.hdf');

[X,map] = imread('skull.hdf',info(4).Reference);

bg = [255 0 0];

A = imread('image.png','BackgroundColor',bg);

MATLAB高级应用——图形及影像处理 350

[A,map,alpha] = imread('image.png');

相关命令:

imfinfo, imwrite,fread,double,uint8,uint16

64.imresize

功能:改变图像大小.

语法:

B = imresize(A,m,method)

B = imresize(A,[mrows ncols],method)

B = imresize(...,method,n)

B = imresize(...,method,h)

65.imrotate

功能:旋转图像.

语法:

B = imrotate(A,angle,method)

B = imrotate(A,angle,method,'crop')

举例

I = imread('ic.tif');

J = imrotate(I,-4,'bilinear','crop');

imshow(I)

figure, imshow(J)

相关命令:

imcrop, imresize

66.imshow

功能:显示图像.

语法:

附录 MATLAB图像处理命令 351

imshow(I,n)

imshow(I,[low high])

imshow(BW)

imshow(X,map)

imshow(RGB)

imshow(...,display_option)

imshow(x,y,A,...)

imshow filename

h = imshow(...)

相关命令:

getimage, imread, iptgetpref, iptsetpref, subimage, truesize, warp

67.imwrite

功能:把图像写入图形文件中.

语法:

imwrite(A,filename,fmt)

imwrite(X,map,filename,fmt)

imwrite(...,filename)

imwrite(...,Param1,Val1,Param2,Val2...)

举例

imwrite(X,map,'flowers.hdf','Compression','none',...

'WriteMode','append')

相关命令:

imfinfo, imread

68.ind2gray

功能:把检索图像转化为灰度图像.

语法:

I = ind2gray(X,map)

举例

load trees

I = ind2gray(X,map);

imshow(X,map)

figure,imshow(I)

MATLAB高级应用——图形及影像处理 352

相关命令:

gray2ind, imshow, rgb2ntsc

69.ind2rgb

功能:转化索引图像为RGB真彩图像.

语法:

RGB = ind2rgb(X,map)

相关命令:

ind2gray, rgb2ind

70.iptgetpref

功能:获取图像处理工具箱参数设置.

语法:

value = iptgetpref(prefname)

举例

value = iptgetpref('ImshowAxesVisible')

value =

off

相关命令:

imshow, iptsetpref

71.iptsetpref

功能:设置图像处理工具箱参数.

语法:

iptsetpref(prefname,value)

举例

iptsetpref('ImshowBorder','tight')

相关命令:

imshow, iptgetpref, truesize

72.iradon

附录 MATLAB图像处理命令 353

功能:进行反Radon变换.

语法:

I = iradon(P,theta)

I = iradon(P,theta,interp,filter,d,n)

[I,h] = iradon(...)

举例

P = phantom(128);

R = radon(P,0:179);

I = iradon(R,0:179,'nearest','Hann');

imshow(P)

figure, imshow(I)

相关命令:

radon, phantom

73.isbw

功能:判断是否为二进制图像.

语法:

flag = isbw(A)

相关命令:

isind, isgray, isrgb

74.isgray

功能:判断是否为灰度图像.

语法:

flag = isgray(A)

相关命令:

isbw, isind, isrgb

75.isind

MATLAB高级应用——图形及影像处理 354

功能:判断是否为索引图像.

语法:

flag = isind(A)

相关命令:

isbw, isgray, isrgb

76.isrgb

功能:判读是否为RGB真彩图像.

语法:

flag = isrgb(A)

相关命令:

isbw, isgray, isind

77.makelut

功能:创建一个用于applylut函数的lookup表.

语法:

lut = makelut(fun,n)

lut = makelut(fun,n,P1,P2,...)

举例

f = inline('sum(x(:)) >= 2');

lut = makelut(f,2)

lut =

0

0

0

1

0

1

1

1

0

1

1

1

1

1

附录 MATLAB图像处理命令 355

1

1

相关命令:

applylut

78.mat2gray

功能:转化矩阵为灰度图像.

语法:

I = mat2gray(A,[amin amax])

I = mat2gray(A)

举例

I = imread('rice.tif');

J = filter2(fspecial('sobel'),I);

K = mat2gray(J);

imshow(I)

figure, imshow(K)

相关命令:

gray2ind

79.mean2

功能:计算矩阵元素的平均值.

语法:

b = mean2(A)

相关命令:

std2, mean, std

80.medfilt2

功能:进行二维中值过滤.

语法:

MATLAB高级应用——图形及影像处理 356

B = medfilt2(A,[m n])

B = medfilt2(A)

B = medfilt2(A,'indexed',...)

举例

I = imread('eight.tif');

J = imnoise(I,'salt & pepper',0.02);

K = medfilt2(J);

imshow(J)

figure, imshow(K)

相关命令:

filter2, ordfilt2, wiener2

81.montage

功能:在矩形框中同时显示多幅图像.

语法:

montage(I)

montage(BW)

montage(X,map)

montage(RGB)

h = montage(...)

举例

load mri

montage(D,map)

附录 MATLAB图像处理命令 357

相关命令:

immovie

82.nlfilter

功能:进行边沿操作.

语法:

B = nlfilter(A,[m n],fun)

B = nlfilter(A,[m n],fun,P1,P2,...)

B = nlfilter(A,'indexed',...)

举例

B = nlfilter(A,[3 3],'median(x(:))');

相关命令:

blkproc, colfilt

83.ntsc2rgb

功能: 转换NTSC的值为RGB颜色空间.

语法:

rgbmap = ntsc2rgb(yiqmap)

RGB = ntsc2rgb(YIQ)

相关命令:

rgb2ntsc, rgb2ind, ind2rgb, ind2gray

84.ordfilt2

功能:进行二维统计顺序过滤.

语法:

B = ordfilt2(A,order,domain)

B = ordfilt2(A,order,domain,S)

MATLAB高级应用——图形及影像处理 358

B = ordfilt2(...,padopt)

相关命令:

medfilt2

85.phantom

功能:产生一个头部幻影图像.

语法:

P = phantom(def,n)

P = phantom(E,n)

[P,E] = phantom(...)

举例

P = phantom('Modified Shepp-Logan',200);

imshow(P)

相关命令:

radon, iradon

86.pixval

功能:显示图像像素信息.

语法:

pixval on

pixval off

pixval

pixval(fig,option)

相关命令:

impixel, improfile

87.qtdecomp

功能:进行四叉树分解.

附录 MATLAB图像处理命令 359

语法:

S = qtdecomp(I)

S = qtdecomp(I,threshold)

S = qtdecomp(I,threshold,mindim)

S = qtdecomp(I,threshold,[mindim maxdim])

S = qtdecomp(I,fun)

S = qtdecomp(I,fun,P1,P2,...)

举例

I = [1 1 1 1 2 3 6 6

1 1 2 1 4 5 6 8

1 1 1 1 10 15 7 7

1 1 1 1 20 25 7 7

20 22 20 22 1 2 3 4

20 22 22 20 5 6 7 8

20 22 20 20 9 10 11 12

22 22 20 20 13 14 15 16];

S = qtdecomp(I,5);

full(S)

ans =

4 0 0 0 2 0 2 0

0 0 0 0 0 0 0 0

0 0 0 0 1 1 2 0

0 0 0 0 1 1 0 0

4 0 0 0 2 0 2 0

0 0 0 0 0 0 0 0

0 0 0 0 2 0 2 0

0 0 0 0 0 0 0 0

相关命令:

qtgetblk, qtsetblk

88.qtgetblk

功能:获取四叉树分解中的块值.

语法:

[vals,r,c] = qtgetblk(I,S,dim)

MATLAB高级应用——图形及影像处理 360

[vals,idx] = qtgetblk(I,S,dim)

举例

[vals,r,c] = qtgetblk(I,S,4)

vals(:,:,1) =

1 1 1 1

1 1 2 1

1 1 1 1

1 1 1 1

vals(:,:,2) =

20 22 20 22

20 22 22 20

20 22 20 20

22 22 20 20

r =

1

5

c =

1

1

相关命令:

qtdecomp, qtsetblk

89.qtsetblk

功能:设置四叉树分解中的块值.

语法:

J = qtsetblk(I,S,dim,vals)

举例

newvals = cat(3,zeros(4),ones(4));

J = qtsetblk(I,S,4,newvals)

J =

0 0 0 0 2 3 6 6

0 0 0 0 4 5 6 8

0 0 0 0 10 15 7 7

附录 MATLAB图像处理命令 361

0 0 0 0 20 25 7 7

1 1 1 1 1 2 3 4

1 1 1 1 5 6 7 8

1 1 1 1 9 10 11 12

1 1 1 1 13 14 15 16

相关命令:

qtdecomp, qtgetblk

90.radon

功能: 计算Radon变换.

语法:

R = radon(I,theta)

R = radon(I,theta,n)

[R,xp] = radon(...)

举例

iptsetpref('ImshowAxesVisible','on')

I = zeros(100,100);

I(25:75,25:75) = 1;

theta = 0:180;

[R,xp] = radon(I,theta);

imshow(theta,xp,R,[]), colormap(hot), colorbar

相关命令:

iradon, phantom

91.rgb2gray

功能: 转换RGB图像或颜色映像表为灰度图像.

语法:

I = rgb2gray(RGB)

newmap = rgb2gray(map)

相关命令:

MATLAB高级应用——图形及影像处理 362

ind2gray, ntsc2rgb, rgb2ind, rgb2ntsc

92.rgb2hsv

功能: 转化RGB值为HSV颜色空间.

语法:

hsvmap = rgb2hsv(rgbmap)

HSV = rgb2hsv(RGB)

相关命令:

hsv2rgb, rgbplot

93.rgb2ind

功能: 转化RGB图像为索引图像.

语法:

[X,map] = rgb2ind(RGB,tol)

[X,map] = rgb2ind(RGB,n)

X = rgb2ind(RGB,map)

[...] = rgb2ind(...,dither_option)

举例

RGB = imread('flowers.tif');

[X,map] = rgb2ind(RGB,128);

imshow(X,map)

相关命令:

cmunique, dither, imapprox, ind2rgb, rgb2gray

94.rgb2ntsc

功能: 转化RGB的值为NTSC颜色空间.

语法:

yiqmap = rgb2ntsc(rgbmap)

YIQ = rgb2ntsc(RGB)

附录 MATLAB图像处理命令 363

相关命令:

ntsc2rgb, rgb2ind, ind2rgb, ind2gray

95.rgb2ycbcr

功能: 转化RGB的值为YcbCr颜色空间.

语法:

ycbcrmap = rgb2ycbcr(rgbmap)

YCBCR = rgb2ycbcr(RGB)

相关命令:

ntsc2rgb, rgb2ntsc, ycbcr2rgb

96.rgbplot

功能:划分颜色映像表.

语法:

rgbplot(map)

举例

rgbplot(jet)

相关命令:

colormap

97.roicolor

功能:选择感兴趣的颜色区.

语法:

BW = roicolor(A,low,high)

BW = roicolor(A,v)

举例

I = imread('rice.tif');

BW = roicolor(I,128,255);

imshow(I);

MATLAB高级应用——图形及影像处理 364

figure, imshow(BW)

相关命令:

roifilt2, roipoly

98.roifill

功能:在图像的任意区域中进行平滑插补.

语法:

J = roifill(Incur)

J = roifill(I)

J = roifill(I,BW)

[J,BW] = roifill(...)

J = roifill(x,y,I,xi,yi)

[x,y,J,BW,xi,yi] = roifill(...)

举例

I = imread('eight.tif');

c = [222 272 300 270 221 194];

r = [21 21 75 121 121 75];

J = roifill(Incur);

imshow(I)

figure, imshow(J)

附录 MATLAB图像处理命令 365

相关命令:

roifilt2, roipoly

99.roifilt2

功能:过滤敏感区域.

语法:

J = roifilt2(h,I,BW)

J = roifilt2(I,BW,fun)

J = roifilt2(I,BW,fun,P1,P2,...)

举例

h = fspecial('unsharp');

J = roifilt2(h,I,BW);

imshow(J)

相关命令:

filter2, roipoly

100.roipoly

功能:选择一个敏感的多边形区域.

语法:

BW = roipoly(Incur)

BW = roipoly(I)

BW = roipoly(x,y,I,xi,yi)

[BW,xi,yi] = roipoly(...)

[x,y,BW,xi,yi] = roipoly(...)

举例

I = imread('eight.tif');

c = [222 272 300 270 221 194];

r = [21 21 75 121 121 75];

BW = roipoly(Incur);

imshow(I)

MATLAB高级应用——图形及影像处理 366

figure, imshow(BW)

相关命令:

roifilt2, roicolor, roifill

101.std2

功能:计算矩阵元素的标准偏移.

语法:

b = std2(A)

相关命令:

corr2, mean2

102.subimage

功能:在一幅图中显示多个图像.

语法:

subimage(X,map)

subimage(I)

subimage(BW)

subimage(RGB)

subimage(x,y,...)

h = subimage(...)

举例

load trees

[X2,map2] = imread('forest.tif');

subplot(1,2,1), subimage(X,map)

subplot(1,2,2), subimage(X2,map2)

相关命令:

附录 MATLAB图像处理命令 367

103.truesize

功能:调整图像显示尺寸.

语法:

truesize(fig,[mrows mcols])

truesize(fig)

相关命令:

imshow, iptsetpref, iptgetpref

104.uint8

功能:转换数据为8位无符号整型.

语法:

B = uint8(A)

举例

a = [1 3 5];

b = uint8(a);

whos

Name Size Bytes Class

a 1x3 24 doublearray

b 1x3 3 uint8 array

相关命令:

double, im2double, im2uint8

105.uint16

功能:转换数据为16位无符号整型.

语法:

I = uint16(X)

MATLAB高级应用——图形及影像处理 368

举例

a = [1 3 5];

b = uint16(a);

whos

Name Size Bytes Class

a 1x3 24 double array

b 1x3 6 uint16 array

相关命令:

double, datatypes, uint8, uint32, int8, int16, int32.

106.warp

功能:将图像显示到纹理映射表面.

语法:

warp(X,map)

warp(I,n)

warp(BW)

warp(RGB)

warp(z,...)

warp(x,y,z,...)

h = warp(...)

举例

[x,y,z] = cylinder;

I = imread('testpat1.tif');

warp(x,y,z,I);

相关命令:

imshow

附录 MATLAB图像处理命令 369

107.wiener2

功能:进行二维适应性去噪过滤处理.

语法:

J = wiener2(I,[m n],noise)

[J,noise] = wiener2(I,[m n])

举例

I = imread('saturn.tif');

J = imnoise(I,'gaussian',0,0.005);

K = wiener2(J,[5 5]);

imshow(J)

figure, imshow(K)

相关命令:

filter2, medfilt2

108.ycbcr2rgb

功能: 转化YcbCr值为RGB颜色空间.

语法:

rgbmap = ycbcr2rgb(ycbcrmap)

RGB = ycbcr2rgb(YCBCR)

相关命令:

ntsc2rgb, rgb2ntsc, rgb2ycbcr

109.zoom

功能:缩放图像.

语法:

zoom on

zoom off

zoom out

MATLAB高级应用——图形及影像处理 370

zoom reset

zoom

zoom xon

zoom yon

zoom(factor)

zoom(fig,option)

相关命令:

imcrop