close all;
clear all;
sourcePic=imread('tx8.jpg');
[height,width,l]=size(sourcePic);
grayPic=zeros(height,width);
for i=1:height %转换成灰度图象
for j=1:width
grayPic(i,j)=(sourcePic(i,j,1)+sourcePic(i,j,2)+sourcePic(i,j,3))/3;
end
end
logNum=0; %log算子的计算值
edgePic=zeros(height,width);
for i=3:height-2 %log算子提取边界
for j=3:width-2
logNum=16*grayPic(i,j)-grayPic(i-2,j)-grayPic(i-1,j-1)-2*grayPic(i-1,j)-grayPic(i-1,j+1)-grayPic(i,j-2)-2*grayPic(i,j-1)-2*grayPic(i,j+1)-grayPic(i,j+2)-grayPic(i+1,j-1)-2*grayPic(i+1,j)-grayPic(i+1,j+1)-grayPic(i+2,j);
if(logNum > 0)
edgePic(i,j)=255;
else
edgePic(i,j)=0;
end
end
end
% Hough变换检测直线，g(x)=(a,p)为边界点对应的平面
ma=180; %a的值为0到180度
mp=round(sqrt(height^2+width^2)); %对应P的最大值
npc=zeros(ma,2*mp); %用于记录(a,p)对应的点的个数
npp=cell(ma,2*mp); %用于记录(a,p)对应的点的坐标
for i=1:height %计算(a,p)的值，并做相应记录
for j=1:width
if(edgePic(i,j)==255)
for k=1:ma
p = round(i*cos(pi*k/180)+j*sin(pi*k/180));
if(p > 0)
%npc(k,mp*2)=npc(k,mp*2)+1;
%npp{k,mp*2}=[npp{k,mp*2},[i,j]'];
%2010.01.05修正
npc(k,mp+p)=npc(k,mp+p)+1;
npp{k,mp+p}=[npp{k,mp+p},[i,j]'];
else
ap=abs(p)+1;
npc(k,ap)=npc(k,ap)+1;
npp{k,ap}=[npp{k,ap},[i,j]'];
end
end
end
end
end
for i=1:ma %根据(a,p)对应的点的个数，用红色标出相应直线
for j=1:mp*2
if(npc(i,j) > 90) %将提取直线的阈值设为90
lp=npp{i,j};
for k=1:npc(i,j)
sourcePic(lp(1,k),lp(2,k),1)=255;
sourcePic(lp(1,k),lp(2,k),2)=255;
sourcePic(lp(1,k),lp(2,k),3)=255;
end
end
end
end
figure,imshow(sourcePic);
ma
mp
