matlab 调用图像放大命令

Posted 2023-03-16

matlab 常用图像放大方法的调用语句，如最近邻域，线性插值，三次样条插值。最好能具体说明其具体用法，在线等。谢谢……

Matlab图像处理函数 汇总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)

siz =

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 参考技术A 用set命令matlab缩小和放大图片的方法
在matlab里直接使用10.5大小的字体（5号字体），
并调整图片的大小（50%），按厘米
set(gcf,'Units','centimeters','position',[12 2 12 8]);
set(gca,'xtick',-8:1:2,'ytick',[0:0.25:1]);%设置刻度
set(gcf,'Units','centimeters','Position',[10 10 7 5]);%设置图片大小为7cm×5cm
%get hanlde to current axis返回当前图形的当前坐标轴的句柄,
%(the first element is the relative distance of the axes to the left edge of the figure,...
%the second the vertical distance from the bottom, and then the width and height;
set(gca,'Position',[.13 .17 .80 .74]);%设置xy轴在图片中占的比例
set(get(gca,'XLabel'),'FontSize',8);%图上文字为8 point或小5号
set(get(gca,'YLabel'),'FontSize',8);
set(get(gca,'TITLE'),'FontSize',8);
set(gca,'fontsize',8);
set(gca,'linewidth',0.5); %坐标线粗0.5磅
set(gca,'box','off');%Controls the box around the plotting area
set(get(gca,'Children'),'linewidth',1.5);%设置图中线宽1.5磅