常用函数列表

附录MATLAB图像处理工具箱函数

表1 通用函数

函数功能语法

colorbar 显示颜色条colorbar

colorbar(...,'peer',axes_handle) colorbar(axes_handle) colorbar('location')

colorbar(...,'PropertyName',pro pertyvalue)

cbar_axes = colorbar(...)

getimage 从坐标轴取得图

像数据

A = getimage(h)

[x,y,A] = getimage(h)

[...,A,flag] = getimage(h)

[...] = getimage

image 创建并显示图像

对象

image(C)

image(x,y,C)

image(...,'PropertyName',Prope

rtyValue,...)

image('PropertyName',Propert

yValue,...) Formal syntax -

PN/PV only

handle = image(...)

imagesc 按图像显示数据

矩阵

imagesc(C)

imagesc(x,y,C)

imagesc(...,clims)

h = imagesc(...)

imshow 显示图像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(…)

imview 利用图像浏览器

显示图像

imview(I)

imview(RGB)

imview(X,map)

imview(I,range)

imview(filename)

imview(...,'InitialMagnification

',initial_mag)

h = imview(...)

imview close all

montage 在矩形框中同时

显示多帧图像

montage(I)

montage(BW)

montage(X,map)

montage(RGB)

h = montage(...)

immovie 创建多帧索引色

图像的电影动画

mov = immovie(X,map)

mov = immovie(RGB)

subimage 在一个图形中显

示多个图像，结合

函数subplot使用

subimage(X,map)

subimage(I)

subimage(BW)

subimage(RGB)

subimage(x,y,...)

h = subimage(...)

truesize 调整图像显示尺

寸

truesize(fig,[mrows mcols])

truesize(fig)

wrap 将图像显示到纹

理映射表面

warp(X,map)

warp(I,n)

warp(BW)

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

h = warp(...)

zoom 缩放图像或图形zoom on

zoom off

zoom out

zoom reset zoom

zoom xon

zoom yon

zoom(factor) zoom(fig, option)

表2 图像文件I/O函数

函数功能语法

imfinfo 返回图像文件信息info = imfinfo(filename,fmt) info = imfinfo(filename)

imread 从图像文件中读取图像A = imread(filename,fmt)

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

[...] = imread(filename)

[...] = imread(URL,...)

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

(CUR, GIF, ICO, and TIFF only)

[...] = imread(..., 'PixelRegion', { ROWS, COLS }) (TIFF only)

[...] = imread(...,'frames',idx) (GIF only) [...] = imread(...,ref) (HDF only) [...] = imread(...,'BackgroundColor',BG) (PNG only)

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

(ICO, CUR, and PNG only)

imwrite 把图像写入图像文件中imwrite(A,filename,fmt)

imwrite(X,map,filename,fmt)

imwrite(...,filename)

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

表3 空间变换函数

函数功能语法

findbounds 为空间变换寻找输出边界outbounds = findbounds(TFORM,inbounds)

fliptform 切换空间变换结构的输入和

输出角色

TFLIP = fliptform(T)

imcrop 剪切图像I2 = imcrop(I)

X2 = imcrop(X,map) RGB2 = imcrop(RGB)

I2 = imcrop(I,rect)

X2 = imcrop(X,map,rect) RGB2 = imcrop(RGB,rect) [...] = imcrop(x,y,...) [A,rect] = imcrop(...) [x,y,A,rect] = imcrop(...)

imresize 图像缩放B = imresize(A,m)

B = imresize(A,m,method)

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

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

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

imrotate 图像旋转B = imrotate(A,angle)

B = imrotate(A,angle,method)

B = imrotate(A,angle,method,bbox)

interp2 2-D数据插值ZI = interp2(X,Y,Z,XI,YI)

ZI = interp2(Z,XI,YI)

ZI = interp2(Z,ntimes)

ZI = interp2(X,Y,Z,XI,YI,method)

imtransform 对图像进行2-D空间变换B = imtransform(A,TFORM)

B = imtransform(A,TFORM,INTERP)

[B,XDATA,YDATA] = imtransform(...) [B,XDATA,YDATA] = imtransform(..., param1, val1, param2, val2,...)

makeresampler 生成重采样结构R = makeresampler(interpolant,padmethod) maketform 生成几何变换结构T = maketform(transformtype,...)

tformarray 多维数组的空间变换B = tformarray(A, T, R, TDIMS_A, TDIMS_B, TSIZE_B, TMAP_B,F)

tformfwd 正向空间变换[X,Y] = tformfwd(T,U,V)

[X1,X2,X3,...] = tformfwd(T,U1,U2,U3,...) X = tformfwd(T,U)

[X1,X2,X3,...] = tformfwd(T,U)

X = tformfwd(T,U1,U2,U3,...)

tforminv 逆向空间变换U = tforminv(X,T)

表4 像素和统计处理函数

函数功能语法

corr2 计算两个矩阵的2-D相关系

数

r = corr2(A,B)

imcontour 创建图像的轮廓图imcontour(I) imcontour(I,n) imcontour(I,v) imcontour(x,y,...) imcontour(...,LineSpec) [C,h] = imcontour(...)

imhist 显示图像的直方图imhist(I,n)

imhist(X,map) [counts,x] = imhist(...)

impixel 确定像素颜色值P = impixel(I)

P = impixel(X,map)

P = impixel(RGB)

P = impixel(I,c,r)

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

P = impixel(RGB,c,r) [c,r,P] = 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,...)

improfile 沿线段计算剖面图的像素值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) [...] = improfile(...,method)

mean2 求矩阵元素平均值 B = mean2(A)

pixval 显示图像像素信息pixval on

pixval off

pixval

pixval(fig,option) pixval(ax,option) pixval(H,option)

regionprops 得到图像区域属性STA TS = regionprops(L,properties) std2 计算矩阵元素的标准偏移 b = std2(A)

表5 图像分析函数

函数功能语法

edge 识别灰度图像中的边界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',...)

qtdecomp 执行四叉树分解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,...)

qtgetblk 获取四叉树分解中的数组块

值

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

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

qtsetblk 设置四叉树分解中的数组块

值

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

表6 图像增强函数

函数功能语法

adapthisteq 执行对比度受限的直方图均

衡

J = adapthisteq(I)

J = adapthisteq(I,param1,val1,param2,val2...)

decorrstretch 对多通道图像应用解卷积延

拓

S = decorrstretch(I)

S = decorrstretch(I,TOL)

histeq 用直方图均等化增强对比度J = histeq(I,hgram)

J = histeq(I,n)

[J,T] = histeq(I,...)

newmap = histeq(X,map,hgram) newmap = histeq(X,map) [newmap,T] = histeq(X,...)

imadjust 调整图像灰度值或颜色映射

表

J = imadjust(I)

J = imadjust(I,[low_in; high_in],[low_out;

high_out])

J = imadjust(...,gamma)

newmap = imadjust(map, [low_in high_in],

[low_out high_out], gamma)

RGB2 = imadjust(RGB1,...)

imnoise 向图像中加入噪声J = imnoise(I,type)

J = imnoise(I,type,parameters)

medfilt2 进行二维中值滤波B = medfilt2(A,[m n])

B = medfilt2(A)

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

ordfilt2 进行二维统计顺序滤波B = ordfilt2(A,order,domain) B = ordfilt2(A,order,domain,S) B = ordfilt2(...,padopt)

stretchlim 得到图像对比度延拓的灰度

上下限

LOW_HIGH = stretchlim(I,TOL)

LOW_HIGH = stretchlim(RGB,TOL)

wiener2 进行二维适应性去噪滤波J = wiener2(I,[m n],noise) [J,noise] = wiener2(I,[m n])

表7 线性滤波函数

函数功能语法

conv2 二维卷积C = conv2(A,B)

C = conv2(hcol,hrow,A) C = conv2(...,'shape')

convmtx2 二维矩阵卷积T = convmtx2(H,m,n) T = convmtx2(H,[m n])

convn n维卷积C = convn(A,B)

C = convn(A,B,'shape')

filter2 二维线性滤波Y = filter2(h,X)

Y = filter2(h,X,shape)

fspecial 创建预定义滤波器h = fspecial(type)

h = fspecial(type,parameters)

imfilter 多维图像滤波B = imfilter(A,H)

B = imfilter(A,H,option1,option2,...)

表8 线性二维滤波器设计函数函数功能语法

freqspace 确定二维频率响应的频率空

间

[f1,f2] = freqspace(n)

[f1,f2] = freqspace([m n])

[x1,y1] = freqspace(...,'meshgrid')

f = freqspace(N)

f = freqspace(N,'whole')

freqz2 计算二维频率响应[H,f1,f2] = freqz2(h,n1,n2) [H,f1,f2] = freqz2(h,[n2 n1]) [H,f1,f2] = freqz2(h)

[H,f1,f2] = freqz2(h,f1,f2) [...] = freqz2(h,...,[dx dy]) [...] = freqz2(h,...,dx)

freqz2(...)

fsamp2 用频率采样法设计二维FIR

滤波器

h = fsamp2(Hd)

h = fsamp2(f1,f2,Hd,[m n])

ftrans2 通过频率转换法设计二维

FIR滤波器

h = ftrans2(b,t)

h = ftrans2(b)

fwind1 用一维窗口方法设计二维

FIR滤波器

h = fwind1(Hd,win)

h = fwind1(Hd,win1,win2)

h = fwind1(f1,f2,Hd,...)

fwind2 用二维窗口方法设计二维

FIR滤波器

h = fwind2(Hd,win)

h = fwind2(f1,f2,Hd,win)

表9 图像变换函数

函数功能语法

dct2 进行二维离散余弦变换B = dct2(A)

B = dct2(A,m,n) B = dct2(A,[m n])

dctmtx 计算离散余弦变换矩阵 D = dctmtx(n)

fft2 进行二维快速傅立叶变换Y = fft2(X)

Y = fft2(X,m,n)

fftn 进行n维快速傅立叶变换Y = fftn(X)

Y = fftn(X,siz)

fftshift 转换快速傅立叶变换的输出

象限

Y = fftshift(X)

Y = fftshift(X,dim)

idct2 计算二维逆离散余弦变换B = idct2(A)

B = idct2(A,m,n) B = idct2(A,[m n])

ifft2 计算二维逆快速傅立叶变换Y = ifft2(X)

Y = ifft2(X,m,n)

y = ifft2(..., 'nonsymmetric') y = ifft2(..., 'nonsymmetric')

ifftn 计算n维逆快速傅立叶变换Y = ifftn(X)

Y = ifftn(X,siz)

y = ifftn(..., 'nonsymmetric') y = ifftn(..., 'nonsymmetric')

iradon 逆Radon变换I = iradon(R,theta)

I = iradon(R, theta, interp, filter, frequency_scaling, output_size)

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

phantom 产生一个头部幻影图像P = phantom(def,n) P = phantom(E,n) [P,E] = phantom(...)

radon 计算Radon变换R=radon(I,theta) [R,xp]=radon(…)

fanbeam 计算扇形投影变换F = fanbeam(I,D)

F = fanbeam(...,param1,val1,param1,val2,...) [F,sensor_positions,fan_rotation_angles] = fanbeam(...)

表10 边沿和块处理函数

函数功能语法

bestblk 确定进行块操作的块大小siz = bestblk([m n],k) [mb,nb] = bestblk([m n],k)

blkproc 实现图像的非重叠（distinct）

块操作

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',...)

col2im 将矩阵的列重新组织到块中A = col2im(B,[m n],[mm nn], block_type) A = col2im(B,[m n],[mm nn])

colfilt 利用列相关函数进行边沿操

作

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',...)

im2col 重调图像块为列B = im2col(A,[m n],block_type) B = im2col(A,[m n])

B = im2col(A,'indexed',...)

nlfilter 通用滑动邻域操作B = nlfilter(A,[m n],fun)

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

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

表11 图像形态学操作函数

函数功能语法

applylut 在二值图像中利用查找表进

行邻域操作

A = applylut(BW,LUT)

bwarea 计算二值图像的对象面积total = bwarea(BW) bweuler 计算二值图像的欧拉数eul = bweuler(BW,n)

bwhitmiss 执行二值图像的击中和击不

中操作

BW2 = bwhitmiss(BW1,SE1,SE2)

BW2 = bwhitmiss(BW1,INTERV AL)

bwlabel 标注二值图像中已连接的部

分

L = bwlabel(BW,n)

[L,num] = bwlabel(BW,n)

bwmorph 二值图像的通用形态学操作BW2 = bwmorph(BW,operation) BW2 = bwmorph(BW,operation,n)

bwperim 计算二值图像中对象的周长BW2 = bwperim(BW1)

BW2 = bwperim(BW1,CONN)

bwselect 在二值图像中选择对象BW2 = bwselect(BW,c,r,n)

BW2 = bwselect(BW,n)

[BW2,idx] = bwselect(...)

BW2 = bwselect(x,y,BW,xi,yi,n) [x,y,BW2,idx,xi,yi] = bwselect(...)

makelut 创建用于applylut函数的查

找表

lut = makelut(fun,n)

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

bwdist 距离变换D = bwdist(BW)

[D,L] = bwdist(BW)

[D,L] = bwdist(BW,METHOD)

imbothat 执行形态学的闭包运算IM2 = imbothat(IM,SE)

IM2 = imbothat(IM,NHOOD)

imclose 图像的闭运算IM2 = imclose(IM,SE)

IM2 = imclose(IM,NHOOD)

imopen 图像的开运算IM2 = imopen(IM,SE)

IM2 = imopen(IM,NHOOD)

imdilate 图像的膨胀IM2 = imdilate(IM,SE)

IM2 = imdilate(IM,NHOOD)

IM2 = imdilate(IM,SE,PACKOPT) IM2 = imdilate(...,PADOPT)

imerode 图像的腐蚀IM2 = imerode(IM,SE)

IM2 = imerode(IM,NHOOD)

IM2 = imerode(IM,SE,PACKOPT,M) IM2 = imerode(...,PADOPT)

imfill 填充图像区域BW2 = imfill(BW,locations)

BW2 = imfill(BW,'holes')

I2 = imfill(I)

BW2 = imfill(BW)

[BW2 locations] = imfill(BW)

BW2 = imfill(BW,locations,CONN) BW2 = imfill(BW,CONN,'holes')

I2 = imfill(I,CONN)

imtophat 用开运算后的图像减去原图

像

IM2 = imtophat(IM,SE)

IM2 = imtophat(IM,NHOOD)

strel 创建形态学结构元素SE = strel(shape,parameters)

表12 区域处理函数

函数功能语法

roicolor 选择感兴趣的颜色区BW = roicolor(A,low,high) BW = roicolor(A,v)

roifill 在图像的任意区域中进行平

滑插补

J = roifill(I,c,r)

J = roifill(I)

J = roifill(I,BW)

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

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

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

roifilt2 滤波特定区域J = roifilt2(h,I,BW)

J = roifilt2(I,BW,fun)

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

roipoly 选择一个感兴趣的多边形区

域

BW = roipoly(I,c,r)

BW = roipoly(I)

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

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

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

表13 图像代数操作函数功能语法imadd 加运算Z = imadd(X,Y) imsubtract 减运算Z = imsubtract(X,Y) immultiply 乘运算Z = immultiply(X,Y) imdivide 除运算Z = imdivide(X,Y)

表14 颜色空间转换函数

函数功能语法

hsv2rgb 转换HSV的值为RGB颜色

空间

M = hsv2rgb(H)

ntsc2rgb 转换NTSC的值为RGB颜色

空间

rgbmap = ntsc2rgb(yiqmap)

RGB = ntsc2rgb(YIQ)

rgb2hsv 转换RGB的值为HSV颜色

空间

cmap = rgb2hsv(M)

rgb2ntsc 转换RGB的值为NTSC颜色

空间

yiqmap = rgb2ntsc(rgbmap)

YIQ = rgb2ntsc(RGB)

rgb2ycbcr 转换RGB的值为YCbCr颜

色空间

ycbcrmap = rgb2ycbcr(rgbmap)

YCBCR = rgb2ycbcr(RGB)

ycbcr2rgb 转换YCbCr的值为RGB颜

色空间

rgbmap = ycbcr2rgb(ycbcrmap)

RGB = ycbcr2rgb(YCBCR)