OpenCV 利用hsv颜色空间的车牌底色检测

叁歲伎倆 2022-07-14 10:57 217阅读 0赞

一个针对车牌颜色分类的小测试，根据hsv颜色空间，遍历像素点后计算在每个颜色下的像素个数，区分蓝，黄，黑，白车牌底色。

#include<windows.h>
    #include<ctime>
    #include <iostream>   
    #include <stdio.h>
    #include <string>
    #include <stdlib.h>
    #include "opencv2/objdetect/objdetect.hpp"
    #include "opencv2/highgui/highgui.hpp"
    #include "opencv2/imgproc/imgproc.hpp"
    #include <opencv2/opencv.hpp> 
    
    using namespace std;  
    using namespace cv;
    char adr[128]={0};
    int main()
    {
    	Mat hsv;
    	Mat imgH ;
    	Mat imgS ;
    	Mat imgV ;
    
    	for (int i=57;i<=114;i++)
    	{
    		int bluenum=0;
    		int yellownum = 0;
    		int whitenum = 0;
    		int blacknum = 0;
    		int othernum = 0;
    		sprintf_s(adr, "C:\\Users\\Administrator\\Desktop\\save\\1 (%d).jpg",i);
    		printf("-------------------------------------------------------\n");
    		printf("当前图片为%d张\n",i);
    	Mat carplate= imread(adr);
    	cvtColor(carplate,hsv,CV_BGR2HSV);
    	vector<Mat> channels; 
    	split(hsv, channels);
    	imgH =  channels.at(0); 
    	imgS = channels.at(1);
    	imgV = channels.at(2);
    
    	for (int i=0;i<hsv.rows;i++)  
    	{  
    		for(int j=0;j<hsv.cols;j++)  
    		{  
    			//h通道/-/
    			 uchar hvalue=imgH.at<uchar>(i,j);  //
    			 //s通道/-/
    			 uchar svalue=imgS.at<uchar>(i,j);  //
    			 //v通道/-/
    			 uchar vvalue=imgV.at<uchar>(i,j);  //
    			// printf("x=%d,y=%d,HSV: H=%d,S=%d,V=%d\n",i,j,hvalue,svalue,vvalue);
    			 if ((hvalue>90&&hvalue<120)&&(svalue>80&&svalue<220)&&(vvalue>80&&vvalue<255))//hsv图像在蓝色区域里
    			 {
    				 //蓝色+1
    				 bluenum++;
    			 }
    			else  if ((hvalue>11&&hvalue<34)&&(svalue>43&&svalue<255)&&(vvalue>46&&vvalue<255))//hsv在黄色区域里
    			 {
    				 //黄色+1
    				 yellownum++;
    			 }
    			else if ((hvalue>0&&hvalue<180)&&(svalue>0&&svalue<255)&&(vvalue>0&&vvalue<46))//hsv在黑色区域里
    			 {
    				 blacknum++;
    				 //黑色+1
    			 }
    		   else	 if ((hvalue>0&&hvalue<180)&&(svalue>0&&svalue<30)&&(vvalue>46&&vvalue<220))//hsv在白色区域里
    			 {
    				 //白色+1
    				 whitenum++;
    			 }
    			else
    			{
    				//其他颜色
    				othernum++;
    			}
    		}
    	}
    	四个颜色值找最大值//
    	if ((bluenum>yellownum)&(bluenum>blacknum)&(bluenum>whitenum)&(bluenum>othernum))
        printf("图%d底色为蓝色\n",i);
    	if ((yellownum>whitenum)&(yellownum>blacknum)&(yellownum>bluenum)&(yellownum>othernum))
    	printf("图%d底色为黄色\n",i);
    	if ((whitenum>yellownum)&(whitenum>blacknum)&(whitenum>bluenum)&(whitenum>othernum))
    	printf("图%d底色为白色\n",i);
    	if ((blacknum>yellownum)&(blacknum>whitenum)&(blacknum>bluenum)&(blacknum>othernum))
    	printf("图%d底色为黑色\n",i);
    	if ((othernum>yellownum)&(othernum>whitenum)&(othernum>bluenum)&(othernum>blacknum))
    	printf("图%d不是车牌\n",i);
    
    }	
    getchar();
    	waitKey(0);
    	return 0;
    }

测试结果如下：  
![这里写图片描述][5902d2d69390eeb544a953318970758e.png]

测试素材：  
![这里写图片描述][b2c15a2786bb1f2fa717e03b0c1389f4.png]

[5902d2d69390eeb544a953318970758e.png]: /images/20220714/5fe979d92ac34df7b7d2aef2a294d4ba.png
[b2c15a2786bb1f2fa717e03b0c1389f4.png]: /images/20220714/a1fac0b185f143a5bca5f0d29c051937.png