这段时间一直在用opencv搞图像处理的问题，发现虽然可调用的函数多，但是直接找相应代码还是很困难，就行寻找连通域，并在连通域外侧加框，对于习惯使用Mat矩形操作的我，真心感觉代码少之又少，为防止以后自己还会用到，特在此记录一下。
#include "stdafx.h"
#include "stdio.h"
#include "Base_process.h"
#include "opencv/cv.h"
#include "opencv/highgui.h"
#include
#include
#include
#include
using namespace std;
using namespace cv;
void main()
{
Mat src = imread("D:\\Recognize_Form_Project\\test_images\\0.jpg");//图片路径/*image180.jpg*/
Mat gray_image;
cvtColor(src, gray_image, CV_BGR2GRAY);
imwrite("src.jpg", src);
Mat binary_image;
adaptiveThreshold(gray_image, binary_image, 255, CV_ADAPTIVE_THRESH_MEAN_C,
CV_THRESH_BINARY_INV, 25, 10); ///局部自适应二值化函数
imwrite("erzhi.jpg", binary_image);
//去噪
Mat de_noise = binary_image.clone();
//中值滤波
medianBlur(binary_image, de_noise, 5);
///////////////////////// 膨胀 ////////////////////
Mat dilate_img;
Mat element = getStructuringElement(MORPH_RECT, Size(20, 20/*15, 15*/));
dilate(de_noise, dilate_img,element);
imwrite("dilate.jpg", dilate_img);
//外部加框
//检测连通域，每一个连通域以一系列的点表示，FindContours方法只能得到第一个域
vector> contours;
vector hierarchy;
findContours(dilate_img, contours, hierarchy, CV_RETR_EXTERNAL, CV_CHAIN_APPROX_NONE);//CV_RETR_EXTERNAL只检测外部轮廓，可根据自身需求进行调整
Mat contoursImage(dilate_img.rows, dilate_img.cols, CV_8U, Scalar(255));
int index = 0;
for (; index >= 0; index = hierarchy[index][0]) {
cv::Scalar color(rand() & 255, rand() & 255, rand() & 255);
// for opencv 2
// cv::drawContours(dstImage, contours, index, color, CV_FILLED, 8, hierarchy);//CV_FILLED所在位置表示轮廓线条粗细度，如果为负值（如thickness==cv_filled），绘制在轮廓内部
// for opencv 3
//cv::drawContours(contoursImage, contours, index, color, cv::FILLED, 8, hierarchy);
cv::drawContours(contoursImage, contours, index, Scalar(0), 1, 8, hierarchy);//描绘字符的外轮廓
Rect rect = boundingRect(contours[index]);//检测外轮廓
rectangle(contoursImage, rect, Scalar(0,0,255), 3);//对外轮廓加矩形框
}
imwrite("zt.jpg", contoursImage）;
cout << "完成检测";
de_noise.release();
element.release();
dilate_img.release();
binary_image.release();
gray_image.release();
}
