车牌识别 之 字符分割

直接贴代码：

#include "stdafx.h"

#include "cv.h"
#include "highgui.h"

using namespace std;
using namespace cv;

IplImage *g_pGrayImage = NULL;  
IplImage *g_pBinaryImage = NULL;  
const char *pstrWindowsBinaryTitle = "二值图";  

void on_trackbar(int pos)  
{  
    // 转为二值图  
    cvThreshold(g_pGrayImage, g_pBinaryImage, pos, 255, CV_THRESH_BINARY);  
    // 显示二值图  
    cvShowImage(pstrWindowsBinaryTitle, g_pBinaryImage);  
} 

int detectionChange(Mat& mat1, Mat& mat2, int number);
void verProjection_calculate(Mat& mat1, int* vArr, int number);
int** verProjection_cut(int* vArr, int width, int* number);
float pixelPercentage(Mat& mat1);


int _tmain(int argc, _TCHAR* argv[])
{
	 const char *pstrWindowsSrcTitle = "原图";  
    const char *pstrWindowsToolBarName = "二值图阈值";  
  
    // 从文件中加载原图  
    IplImage *pSrcImage = cvLoadImage("plate.jpg", CV_LOAD_IMAGE_UNCHANGED);  

	if (pSrcImage==NULL)
		return -1;
  
    // 转为灰度图  
    g_pGrayImage =  cvCreateImage(cvGetSize(pSrcImage), IPL_DEPTH_8U, 1);  
    cvCvtColor(pSrcImage, g_pGrayImage, CV_BGR2GRAY);  
  
    // 创建二值图  
    g_pBinaryImage = cvCreateImage(cvGetSize(g_pGrayImage), IPL_DEPTH_8U, 1);  
  
    // 显示原图  
    cvNamedWindow(pstrWindowsSrcTitle, CV_WINDOW_AUTOSIZE);  
    cvShowImage(pstrWindowsSrcTitle, pSrcImage);  
    // 创建二值图窗口  
    cvNamedWindow(pstrWindowsBinaryTitle, CV_WINDOW_AUTOSIZE);  
  
    // 滑动条    
    //int nThreshold = 0;  
    //cvCreateTrackbar(pstrWindowsToolBarName, pstrWindowsBinaryTitle, &nThreshold, 254, on_trackbar);    
    //on_trackbar(1);  

	// 转为二值图  
    cvThreshold(g_pGrayImage, g_pBinaryImage, 190, 255, CV_THRESH_BINARY);  
    // 显示二值图  
    cvShowImage(pstrWindowsBinaryTitle, g_pBinaryImage);  

	// 字符分割
	Mat img_3;
	detectionChange((Mat)g_pBinaryImage, img_3, 7);  
	imshow(" 边缘分离 ",img_3);


	int width, reWidth=30, wWidth=20, pic_width;  
    int height, reHeight=100, wHeight = 20; 
	int pic_ArrNumber;  
    int vArr[100];  
    int **pic_Arr;
	Mat img_4 = img_3;
	// 调整图片的大小。
	resize(img_3,img_4,Size(100,30));
	verProjection_calculate(img_4, vArr, reHeight);  
    pic_Arr = verProjection_cut(vArr, reHeight, &pic_ArrNumber);  

	int i;
	for(i=0; i< pic_ArrNumber; i++){  
        printf("pic_Arr[%d]:%d, %d\n", i, pic_Arr[i][0], pic_Arr[i][1]);                                                               
    }  
	char str[20]={0};
    sprintf(str, "%d", i+3);  
    namedWindow(str);  
    imshow("缩小的图像", img_4);  


	Mat img_5; 
    IplImage pI_1 = (Mat)img_4;  
    IplImage pI_2;
	float percentage = 0.0;  
	CvScalar s1;  
	char str1[20]={0};
	for(i=0; i< pic_ArrNumber; i++){  
        pic_width = pic_Arr[i][1] - pic_Arr[i][0];  
		// 字体宽度的度量。
        if(pic_width < 3){  
            continue;  
        }  
   
        img_5 = cv::Mat(reWidth, pic_Arr[i][1] - pic_Arr[i][0], CV_8UC1, 1);  
        pI_2 = img_5;  
        for(int j=0; j= number){  
            width_1 = i;  
            break;  
        }else{  
            width_1 = i;      
        }  
    }  
   
    for(i=width-1; i> 0; i--){  
        sum = 0;  
        sum_2 = 0;  
        for(j=0; j= number){  
            width_2 = i;  
            break;    
        }else{  
            width_2 = i;  
        }  
    }  
    if(width_2 <= width_1){  
        width_2 = width;      
    }  
    mat2 = cv::Mat(width_2 - width_1 + 1, height, CV_8UC1, 1);  
    pI_2 = mat2;  
    for(i=width_1; i<= width_2; i++){  
        for(j=0; j 20){  
                vArr[j] += 1;                 
            }     
        }  
    }  
}  
   
int** verProjection_cut(int* vArr, int width, int* number){  
    int **a;  
    int i, flag = 0;  
    int num = 0;  
    int threshold = 2;  
   
    a = (int**)malloc(width / 2 * sizeof(int*));  
   
    for(i=0; i threshold)){  
            a[num] = (int* )malloc(2 * sizeof(int));  
            a[num][0] = i;  
            flag = 1;  
        }else if((vArr[i] > threshold) && (vArr[i+1] <= threshold) && (flag != 0)){  
            a[num][1] = i;  
            num += 1;  
            flag = 0;  
        }  
    }  
    *number = num;  
   
    return a;  
}

float pixelPercentage(Mat& mat1){  
    IplImage pI_1 = mat1;  
    CvScalar s1;  
    int width = mat1.rows;  
    int height = mat1.cols;  
    int i, j;  
    float sum = 0, allSum = 0, tmp;  
   
    for(i=0; i 20){  
                sum += 1;  
            }  
            allSum += 1;  
        }     
    }  
    tmp = sum / allSum;  
   
    return tmp;  
} 

分割结果演示：