基于字符轮廓与形态学运算的车牌定位算法

%%%%车牌定位算法 clear all clc img=imread('D:\Matlab\work\plates\car4.jpg'); I=rgb2gray(img); imwrite(I,'D:\Matlab\work\plates\gray.jpg'); e=edge(I,'canny',0.25); imwrite(e,'D:\Matlab\work\plates\canny.jpg'); %figure,imshow(I,[]); %figure,imshow(e); [row,clo]=size(I); r=zeros(row,clo); %%%%%%%%%%%字符轮廓检测 for i=2:row-1 for j=2:clo-1 if(e(i,j)==1) if(e(i-1,j-1)==1 && e(i-1,j+1)==0 &&e(i+1,j-1)==0 ) r(i,j)=1; r(i-1,j-1)=1; end if(e(i+1,j+1)==1 && e(i+1,j-1)==0 &&e(i-1,j+1)==0 ) r(i,j)=1; r(i+1,j+1)=1; end if(e(i-1,j+1)==1 && e(i-1,j-1)==0 &&e(i+1,j+1)==0 ) r(i,j)=1; r(i-1,j+1)=1; end if(e(i+1,j-1)==1 && e(i-1,j-1)==0 &&e(i+1,j+1)==0 ) r(i,j)=1; r(i+1,j-1)=1; end if(e(i-1,j)==1 && e(i-1,j-1)==0 &&e(i-1,j+1)==0 ) r(i,j)=1; r(i-1,j)=1; end if(e(i+1,j)==1 && e(i+1,j-1)==0 &&e(i+1,j+1)==0 ) r(i,j)=1; r(i+1,j)=1; end end end end %%%%%%%%%%%%%%%%%%%小范围统计 step*step step=4; row1=floor(row/step); clo1=floor(clo/step); W=zeros(row,clo); WW=zeros(row,clo); RR=zeros(row1,clo1); R=zeros(row1,clo1); count=0;%%%%%%%字符轮廓点统计 for i=2:row1-1 for j=2:clo1-1 ii=(i-1)*step; jj=(j-1)*step; count=sum(sum(r(ii+1:ii+step,jj+1:jj+step))); if (count>1) RR(i,j)=1; W(ii+1:ii+step,jj+1:jj+step)=1; end end end %figure,imshow(W); imwrite(W,'D:\Matlab\work\plates\轮廓.jpg'); %%%%%%横向膨胀---隔一膨胀 %for i=1:row1 % for j=2:clo1-1 % if(RR(i,j-1)==1 && RR(i,j+1)==1) % ii=(i-1)*step; % jj=(j-1)*step; % RR(i,j)=1; % W(ii+1:ii+step,jj+1:jj+step)=1; % end % end %end %%%%%%横向膨胀,五步填充，消除横向缝隙 %%%%%%left , right 左右界，填充【 left，right】之间的缝隙 left=0; right=0; %%%%%%%%%%%lstart,rend,映射到原图像中的横向坐标 lstart=0; rend=0; W(:,:)=0; for i=1:row1 for j=3:clo1-2 left=0;right=0; for k=j-1:-1:j-2 if (RR(i,k)==1) left=k; break; end end for k=j+1:j+2 if(RR(i,k)==1) right=k; break; end end if(left>0 && right>0) RR(i,left:right)=1; ii=(i-1)*step; lstart=(left-1)*step; rend=right*step; W(ii+1:ii+step,lstart+1:rend)=1; end end end %%%figure,imshow(W); %%%%%%纵向膨胀，五步填充，三步效果较差，消除纵向缝隙 high=0; low=0; %%%%%%%%%%%%%%hstart,lend 映射到原图像纵坐标 hstart=0; lend=0; for i=3:row1-2 for j=1:clo1 high=0;low=0; for k=i-1:-1:i-2 if (RR(k,j)==1) high=k; break; end end for k=i+1:i+2 if(RR(k,j)==1) low=k; break; end end if(high>0 && low>0) RR(high:low,j)=1; hstart=(high-1)*step; lend=high*step; jj=(j-1)*step; W(hstart+1:lend,jj+1:jj+step)=1; end end end %figure,imshow(W); imwrite(W,'D:\Matlab\work\plates\膨胀.jpg'); %%%%%%%%%%%%利用宽度阈值，消除干扰 Twidth1=10; Twidth2=18; W(:,:)=0; left=0; right=0; lstart=0;rend=0; for i=1:row1 for j=1:clo1 if(RR(i,j)==1) k=j+1; left=j;right=j; while(RR(i,k)==1 && k<clo1) k=k+1; end right=k-1; if((right-left)<Twidth2 &&(right-left)>Twidth1) R(i,left:right)=1; ii=(i-1)*step; lstart=(left-1)*step; rend=right*step; W(ii+1:ii+step,lstart+1:rend)=1; end j=right+1; end end end RR(:,:)=0; %figure,imshow(W); imwrite(W,'D:\Matlab\work\plates\水平干扰.jpg'); %%%%%%%%%%%%%%%%%%%%候选车牌区域提取 %%%%% N 候选车牌区域数最大值 %%%%% T 质心 横、纵坐标差值阈值，即如果两区域，质心距离大于T %%%%% 则认为两候选区域为单独区域 %%%%% weightRow[],weightClo[]为质心横，纵坐标数组 %%%%% width[], height[] 为候选区域宽，高均值 %%%%% CurRow CurClo CurWidth 当前区域横、纵坐标及宽度 N=20; T=15; weightRow(N)=0; weightClo(N)=0; width(N)=0; height(N)=0; left=0; right=0; lstart=0; rend=0; WW=zeros(row,clo); CurRow=0; CurClo=0; CurWidth=0; for i=row1:-1:1 j=1; while(j<clo) left=j;right=j; if(j<clo1+1 && R(i,j)==1) k=j+1; while(k<clo1+1 && R(i,k)==1 ) k=k+1; end right=k-1; if((right-left)<Twidth1) %RR(i,left:right)=0; else ii=(i-1)*step; lstart=(left-1)*step; rend=right*step; WW(ii+1:ii+step,lstart+1:rend)=1; %%%%%%%%%%%%%%%%%%%质心横、纵坐标 CurRow=i; CurClo=round((left+right)/2); CurWidth=right-left+1; l=0; while(l<N) l=l+1; if(height(l)==0)%%%%%初始找到,或示找到匹配项 weightRow(l)=CurRow; weightClo(l)=CurClo; width(l)=CurWidth; height(l)=1; break; else if (abs(weightRow(l)-CurRow)<T && abs(weightClo(l)-CurClo)<T) %%%%%%%%%%%%%%%%%%%%对候选区域进行横、纵、宽、高进行更新，全平均法 weightRow(l)=round((height(l)*weightRow(l)+CurRow)/(height(l)+1)); weightClo(l)=round((height(l)*weightClo(l)+CurClo)/(height(l)+1)); width(l)=round((height(l)*width(l)+CurWidth)/(height(l)+1)); height(l)=height(l)+1; %%%%%更新后消除本区域 R(i,left:right)=0; break; end end end end j=right+1; else j=j+1; end end end %%%%%%%%显示 %figure,imshow(WW); %%%%%%%%%%%%%%%%%%%%%%%%%%%%候选区域进行宽高比生成 %%%%%%%%%%%%%rateCount候选区域个数 %%%%%%%%%%%%%rateValue,rateIndex与标准系数StandRate=0.318=140/440最接近候选区域值与索引值 %%%%% rate[] 为候选区域高宽比 rate(N)=0; StandRate=0.318; Theight=4; for l=1:N if(height(l)==0) break; elseif (height(l)<Theight) rate(l)=5*StandRate; else rate(l)=1.0*height(l)/width(l); end end %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%候选区域宽高比检测 Result=zeros(row,clo); temp=0; Candidade(N)=0; CandidateNumber=1; l=1; while(rate(l)>0) if(rate(l)==0) break; end minValue=0; minIndex=0; FinalHighStart=0;FinalLowEnd=0; FinalLeftStart=0; FinalRightEnd=0; [minValue,minIndex]=min(abs(rate-StandRate)); if (minValue>0.2)%%%%%%%%宽高比与标准值的差值上限>0.2认为没有候选区 break; else Candidate(CandidateNumber)=minIndex; CandidateNumber=CandidateNumber+1 ; end %%%%%%%%%%标记索引项，避免重复检测 rate(minIndex)=5*StandRate; temp=0; temp=floor(weightRow(minIndex)-height(minIndex)); if(temp>0) FinalHighStart=temp; else FinalHighStart=1; end temp=floor(weightRow(minIndex)+height(minIndex)); if(temp<ro