基于MATLAB的车牌识别系统

function [d]=main(jpg) close all clc I=imread('car2.jpg'); figure(1),imshow(I);title('原图') I1=rgb2gray(I); figure(2),subplot(1,2,1),imshow(I1);title('灰度图'); figure(2),subplot(1,2,2),imhist(I1);title('灰度图直方图'); I2=edge(I1,'roberts',0.15,'both'); figure(3),imshow(I2);title('robert算子边缘检测') se=[1;1;1]; I3=imerode(I2,se); figure(4),imshow(I3);title('腐蚀后图像'); se=strel('rectangle',[25,25]); I4=imclose(I3,se); figure(5),imshow(I4);title('平滑图像的轮廓'); I5=bwareaopen(I4,2000); figure(6),imshow(I5);title('从对象中移除小对象'); [y,x,z]=size(I5); myI=double(I5); tic Blue_y=zeros(y,1); for i=1:y for j=1:x if(myI(i,j,1)==1) Blue_y(i,1)= Blue_y(i,1)+1;%蓝色像素点统计 end end end [temp MaxY]=max(Blue_y);%Y方向车牌区域确定 PY1=MaxY; while ((Blue_y(PY1,1)>=5)&&(PY1>1)) PY1=PY1-1; end PY2=MaxY; while ((Blue_y(PY2,1)>=5)&&(PY2<y)) PY2=PY2+1; end IY=I(PY1:PY2,:,:); %%%%%% X方向 %%%%%%%%% Blue_x=zeros(1,x);%进一步确定x方向的车牌区域 for j=1:x for i=PY1:PY2 if(myI(i,j,1)==1) Blue_x(1,j)= Blue_x(1,j)+1; end end end PX1=1; while ((Blue_x(1,PX1)<3)&&(PX1<x)) PX1=PX1+1; end PX2=x; while ((Blue_x(1,PX2)<3)&&(PX2>PX1)) PX2=PX2-1; end PX1=PX1-1;%对车牌区域的校正 PX2=PX2+1; dw=I(PY1:PY2-8,PX1:PX2,:); t=toc; figure(7),subplot(1,2,1),imshow(IY),title('行方向合理区域'); figure(7),subplot(1,2,2),imshow(dw),title('定位剪切后的彩色车牌图像') imwrite(dw,'dw.jpg'); [filename,filepath]=uigetfile('dw.jpg','输入一个定位裁剪后的车牌图像'); jpg=strcat(filepath,filename); a=imread('dw.jpg'); b=rgb2gray(a); imwrite(b,'1.车牌灰度图像.jpg'); figure(8);subplot(3,2,1),imshow(b),title('1.车牌灰度图像') g_max=double(max(max(b))); g_min=double(min(min(b))); T=round(g_max-(g_max-g_min)/3); % T 为二值化的阈值 [m,n]=size(b); d=(double(b)>=T); % d:二值图像 imwrite(d,'2.车牌二值图像.jpg'); figure(8);subplot(3,2,2),imshow(d),title('2.车牌二值图像') figure(8),subplot(3,2,3),imshow(d),title('3.均值滤波前') % 滤波 h=fspecial('average',3); d=im2bw(round(filter2(h,d))); imwrite(d,'4.均值滤波后.jpg'); figure(8),subplot(3,2,4),imshow(d),title('4.均值滤波后') % 某些图像进行操作 % 膨胀或腐蚀 % se=strel('square',3); % 使用一个3X3的正方形结果元素对象对创建的图像进行膨胀 % 'line'/'diamond'/'ball'... se=eye(2); % eye(n) returns the n-by-n identity matrix 单位矩阵 [m,n]=size(d); if bwarea(d)/m/n>=0.365 d=imerode(d,se); elseif bwarea(d)/m/n<=0.235 d=imdilate(d,se); end imwrite(d,'5.膨胀或腐蚀处理后.jpg'); figure(8),subplot(3,2,5),imshow(d),title('5.膨胀或腐蚀处理后') % 寻找连续有文字的块，若长度大于某阈值，则认为该块有两个字符组成，需要分割 d=qiege(d); [m,n]=size(d); figure,subplot(2,1,1),imshow(d),title(n) k1=1;k2=1;s=sum(d);j=1; while j~=n while s(j)==0 j=j+1; end k1=j; while s(j)~=0 && j<=n-1 j=j+1; end k2=j-1; if k2-k1>=round(n/6.5) [val,num]=min(sum(d(:,[k1+5:k2-5]))); d(:,k1+num+5)=0; % 分割 end end % 再切割 d=qiege(d); % 切割出 7 个字符 y1=10;y2=0.25;flag=0;word1=[]; while flag==0 [m,n]=size(d); left=1;wide=0; while sum(d(:,wide+1))~=0 wide=wide+1; end if wide<y1 % 认为是左侧干扰 d(:,[1:wide])=0; d=qiege(d); else temp=qiege(imcrop(d,[1 1 wide m])); [m,n]=size(temp); all=sum(sum(temp)); two_thirds=sum(sum(temp([round(m/3):2*round(m/3)],:))); if two_thirds/all>y2 flag=1;word1=temp; % WORD 1 end d(:,[1:wide])=0;d=qiege(d); end end % 分割出第二个字符 [word2,d]=getword(d); % 分割出第三个字符 [word3,d]=getword(d); % 分割出第四个字符 [word4,d]=getword(d); % 分割出第五个字符 [word5,d]=getword(d); % 分割出第六个字符 [word6,d]=getword(d); % 分割出第七个字符 [word7,d]=getword(d); subplot(5,7,1),imshow(word1),title('1'); subplot(5,7,2),imshow(word2),title('2'); subplot(5,7,3),imshow(word3),title('3'); subplot(5,7,4),imshow(word4),title('4'); subplot(5,7,5),imshow(word5),title('5'); subplot(5,7,6),imshow(word6),title('6'); subplot(5,7,7),imshow(word7),title('7'); [m,n]=size(word1); % 商用系统程序中归一化大小为 40*20,此处演示 word1=imresize(word1,[40 20]); word2=imresize(word2,[40 20]); word3=imresize(word3,[40 20]); word4=imresize(word4,[40 20]); word5=imresize(word5,[40 20]); word6=imresize(word6,[40 20]); word7=imresize(word7,[40 20]); subplot(5,7,15),imshow(word1),title('1'); subplot(5,7,16),imshow(word2),title('2'); subplot(5,7,17),imshow(word3),title('3'); subplot(5,7,18),imshow(word4),title('4'); subplot(5,7,19),imshow(word5),title('5'); subplot(5,7,20),imshow(word6),title('6'); subplot(5,7,21),imshow(word7),title('7'); imwrite(word1,'1.jpg'); imwrite(word2,'2.jpg'); imwrite(word3,'3.jpg'); imwrite(word4,'4.jpg'); imwrite(word5,'5.jpg'); imwrite(word6,'6.jpg'); imwrite(word7,'7.jpg'); liccode=char(['0':'9' 'A':'Z' '苏豫陕鲁']); %建立自动识别字符代码表 SubBw2=zeros(40,20); l=1; for I=1:7 ii=int2str(I); t=imread([ii,'.jpg']); SegBw2=imresize(t,[40 20],'nearest'); if l==1 %第一位汉字识别 kmin=37; kmax=40; elseif l==2 %第二位 A~Z 字母识别 kmin=11; kmax=36; else l>=3 %第三位以后是字母或数字识别 kmin=1; kmax=36; end for k2=kmin:kmax fname=strcat('字符模板\',liccode(k2),'.jpg'); SamBw2 = imread(fname); for i=1:40 for j=1:20 SubBw2(i,j)=SegBw2(i,j)-SamBw2(i,j); end end % 以上相当于两幅图相减得到第三幅图 Dmax=0; for k1=1:40 for l1=1:20 if ( SubBw2(k1,l1) > 0 | SubBw2(k1,l1) <0 ) Dmax=Dmax+1; end end end Error(k2)=Dmax; end Error1=Error(kmin:kmax); MinError=min(Error1); findc=find(Error1==MinError); Code(l*2-1)=liccode(findc(1)+kmin-1); Code(l*2)=' '; l=l+1; end figure(10),imshow(dw),title (['车牌号码:', Code],'Color','b');