文章和代码以及样例图片等相关资源,已经归档至【Github仓库:digital-image-processing-matlab】。
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
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
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
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
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);
bwarea(BW)
ans =
15799
相关命令: bweuler, bwperim
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
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
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
功能:标注二进制图像中已连接的部分。
语法:
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
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');
imshow(BW1);
BW2 = bwmorph(BW1,'remove');
BW3 = bwmorph(BW1,'skel',Inf);
imshow(BW2)
figure, imshow(BW3)
相关命令:
bweuler, bwperim, dilate, erode
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)
相关命令:
bwarea, bweuler, bwfill
参考文献: