【opencv学习笔记】3、opencv图像二值化

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#include <opencv2\opencv.hpp>
#include <iostream>

using namespace std;
//定义灰度图像变量
IplImage *g_GrayImage = NULL;
//定义二值化图片变量
IplImage *g_BinaryImage = NULL;
//定义二值化窗口标题
const char *WindowBinaryTitle = "二值化图片";
//定义滑块响应函数
void on_trackbar(int n1){
	//根据传递进来的参数，进行图像二值化操作，参数1-输入图像（必须为单通道灰度图），参数2-输出边缘图像，单通道黑白图，参数3-阀值，参数4-最大值，参数5-运算方法

	/*
	参数5
	Threshold types 

	enum

	{

		CV_THRESH_BINARY = 0, // value = value > threshold ? max_value : 0      

		CV_THRESH_BINARY_INV = 1,  // value = value > threshold ? 0 : max_value      

		CV_THRESH_TRUNC = 2,  // value = value > threshold ? threshold : value   

		CV_THRESH_TOZERO = 3,  // value = value > threshold ? value : 0           

		CV_THRESH_TOZERO_INV = 4,  // value = value > threshold ? 0 : value           

		CV_THRESH_MASK = 7,

		CV_THRESH_OTSU = 8  // use Otsu algorithm to choose the optimal threshold value; combine the flag with one of the above CV_THRESH_* values 

	};
	*/
	cvThreshold(g_GrayImage, g_BinaryImage, n1, 255, CV_THRESH_BINARY);
	//显示二值化后的图片
	cvShowImage(WindowBinaryTitle, g_BinaryImage);
}
int main(){
	//创建源图像窗口标题变量
	const char *WindowSrcTitle = "灰度图像";
	//创建滑块标题变量
	const char *TheSliderTitle = "二值化阀值";
	//原图位置
	const char *SrcPath = "C:\\Users\\Administrator\\Documents\\visual studio 2013\\Projects\\cv\\Debug\\a.jpg";
	//载入原图
	IplImage *SrcImage = cvLoadImage(SrcPath,CV_LOAD_IMAGE_UNCHANGED);
	//单通道灰度化处理
	g_GrayImage = cvCreateImage(cvSize(SrcImage->width,SrcImage->height), IPL_DEPTH_8U, 1);
	cvCvtColor(SrcImage, g_GrayImage, CV_BGR2GRAY);

	//创建二值图
	g_BinaryImage = cvCreateImage(cvGetSize(g_GrayImage), IPL_DEPTH_8U, 1);
	//创建原图窗口
	cvNamedWindow(WindowSrcTitle, CV_WINDOW_AUTOSIZE);
	//显示原图到原图窗口
	cvShowImage(WindowSrcTitle, SrcImage);

	//创建二值窗口
	cvNamedWindow(WindowBinaryTitle, CV_WINDOW_AUTOSIZE);

	//创建滑块
	int n = 0;
	cvCreateTrackbar(TheSliderTitle, WindowBinaryTitle, &n, 254, on_trackbar);

	//先执行一次
	on_trackbar(1);

	cvWaitKey(0);

	//销毁窗口，释放图片
	cvDestroyWindow(WindowBinaryTitle);
	cvDestroyWindow(WindowSrcTitle);
	cvReleaseImage(&g_BinaryImage);
	cvReleaseImage(&g_GrayImage);
	cvReleaseImage(&SrcImage);
	return 0;
}