cpl.rar_数学形态学_车牌定位

%程序功能：实现车牌自动定位 %作者：郭雄伟 clear;clc;close all filename='36.jpg'; %输入使用的图片名 figure imshow(filename);title('原图') %%%%%%%%%%%%%%%%%%%%%%%%%%%%%% I=im2gray(filename); %调用自编函数读取图像，并转化为灰度图象； %%%%%%%%%%%%%%%%%%%%%%%%%%%%%% figure imshow(I);title('灰度图') %%%%%%%%%%%%%%%%%%%%%%%%%%%%%% I=medfilt2(I); %中值滤波 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%% figure imshow(I);title('中值滤波后的灰度图') tic %计时开始 [height,width]=size(I); %读取图片大小信息 I_edge=zeros(height,width); % 创建height*width的矩阵 for i=1:width-1 % 对每一列开始遍历 I_edge(:,i)=abs(I(:,i+1)-I(:,i)); % 每列的值赋为原图像中左右两列相减的绝对值(即梯度) end I_edge=(255/(max(max(I_edge))-min(min(I_edge))))*(I_edge-min(min(I_edge)));% 归一化处理(0～255) [I_edge,y1]=select(I_edge,height,width); %调用select函数，进行边缘提取 figure imshow(I_edge);title('选择') BW2 = I_edge;%BW2为0和255二值图像 %%%%%%%%%%%%%%%%%%%%%%%%%%%一些形态学处理 SE=strel('rectangle',[10,10]); IM2=imerode(BW2,SE);%腐蚀 figure imshow(IM2);title('腐蚀'); IM2=bwareaopen(IM2,20);%开运算，消除细小物体 figure imshow(IM2);title('开运算'); IM3=imdilate(IM2,SE);%膨胀 figure imshow(IM2);title('膨胀'); %%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%投影估计车牌位置 p_h=projection(double(IM3),'h'); %调用projection函数，水平投影 if(p_h(1)>0) p_h=[0,p_h]; end p_v=projection(double(IM3),'v'); %调用projection函数，垂直投影 if(p_v(1)>0) p_v=[0,p_v]; end p_h=double((p_h>5)); p_h=find(((p_h(1:end-1)-p_h(2:end))~=0)); len_h=length(p_h)/2; p_v=double((p_v>5)); p_v=find(((p_v(1:end-1)-p_v(2:end))~=0)); len_v=length(p_v)/2; %%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%粗略计算车牌候选区 k=1; for i=1:len_h for j=1:len_v s=IM3(p_h(2*i-1):p_h(2*i),p_v(2*j-1):p_v(2*j)); if(mean(mean(s))>0.1) %根据投影值变化确定阈值，此值可以调节 p{k}=[p_h(2*i-1),p_h(2*i)+1,p_v(2*j-1),p_v(2*j)+1]; k=k+1; end end end k=k-1; %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%进一步缩小车牌候选区 for i=1:k edge_IM3=double(edge(double(IM3(p{i}(1):p{i}(2),p{i}(3):p{i}(4))),'canny')); [x,y]=find(edge_IM3==1); p{i}=[p{i}(1)+min(x),p{i}(2)-(p{i}(2)-p{i}(1)+1-max(x)),...%矩形的行起点与终点 p{i}(3)+min(y),p{i}(4)-(p{i}(4)-p{i}(3)+1-max(y))]; %矩形的列起点与终点 p_center{i}=[fix((p{i}(1)+p{i}(2))/2),fix((p{i}(3)+p{i}(4))/2)]; %矩形中心 p_ratio(i)=(p{i}(4)-p{i}(3))/(p{i}(2)-p{i}(1)); % 矩形长宽比 end %%%%%%%%%%%%%%%%%%%%%%%%%%%%% %对上面参数和变量的说明：p为一元胞，用于存放每个图像块的左上和右下两个点的坐标； %存放格式为：p{k}=[x1,x2,y1,y2]；x1,x2分别为行坐标，y1,y2为列坐标 %p_center为一元胞,用于存放每个图像块的中心坐标,p_center{k}=[x,y];x,y分别为行,列坐标 %p_ratio为一矩阵，用来存放图像块的长宽比例 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%合并临近区域%%%%%%% %如果有多个区域则执行合并 if k>1 n=0; ncount=zeros(1,k); for i=1:k-1 %需要调整if条件中的比例 %检查是否满足合并条件 if(abs(p{i}(1)+p{i}(2)-p{i+1}(1)-p{i+1}(2))<=height/30&&abs(p{i+1}(3)-p{i}(4))<=width/15)%设置合并的阈值 p{i+1}(1)=min(p{i}(1),p{i+1}(1)); p{i+1}(2)=max(p{i}(2),p{i+1}(2)); p{i+1}(3)=min(p{i}(3),p{i+1}(3)); p{i+1}(4)=max(p{i}(4),p{i+1}(4)); %向后合并 n=n+1; ncount(n)=i+1; end end %如果有合并，求出合并后最终区域 if(n>0) d_ncount=ncount(2:n+1)-ncount(1:n);%避免重复记录临近的多个区域。 index=find(d_ncount~=1); m=length(index); for i=1:m pp{i}=p{ncount(index(i))}; %重新记录合并区域的比例 pp_ratio(i)=(pp{i}(4)-pp{i}(3))/(pp{i}(2)-pp{i}(1)); %长宽比例 end p=pp;%更新区域记录 p_ratio=pp_ratio; %更新区域比例记录 clear pp;clear pp_ratio; %清除部分变量 end end k=length(p); %更新区域个数 %%%%%%%%%%%%%%合并结束%%%%%%%%%%%%%%%%%%%%% %%%%%%%%根据区域比例判断是否为车牌区域%%%%%%%%%%%% m=1;T=0.6*max(p_ratio);%此式中的0.6参数可以调节调整 for i=1:k if(p_ratio(i)>=T&p_ratio(i)<10)%有区域长宽比值判断是否为车牌,此值需要根据实际调节 %%%%% %%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%根据区域占图片比例判断 disw=p{i}(4)-p{i}(3); dish=p{i}(2)-p{i}(1); if((disw>=width*0.01 & disw<=width*0.5)... %假定车牌长度大于整张图片长度的0.01，小于0.5，可以 &(dish>=height*0.01 & dish<=height*0.5)) %根据实际要求调节 %参数可修改 %车牌区域宽度各高度占整个图像的大小不能太大也不能太小 p1{m}=p{i}; m=m+1; end %%%%% %%%%%%%%%%%%%%%%%%%%%%%%%% end end p=p1;clear p1; k=m-1; %更新区域数 %%%%%%%%%%%判定结束%%%%%%%%%%%%%%%%%%%%% toc %计时结束 %%%%%%%%%%%%%%%%%显示选定的车牌区域 figure; for i=1:k subplot(1,k,i); index=p{i}; imshow(I(index(1)-2:index(2),index(3):index(4))); end if(k==1) imwrite(I(index(1)-2:index(2),index(3):index(4)),'车牌.jpg'); end