cvThreshold() 阈值化

OpenCV中阈值化的5种形式

CVAPI(double)  cvThreshold( const CvArr*  src, CvArr*  dst,
                            double  threshold, double  max_value,
                            int threshold_type );

src源图像,dst输出图像,threshold阈值,max_value,threshold_type 上面贴图的5种阈值化形式

阈值化的图像必须是单通道的，需要先用cvSplit() 和cvAddWeighted()

测试用图：

程序代码：

#include 
#include 
#include 
using namespace std;

int t,Threshold,Max_value;

IplImage *img_in = cvLoadImage("test.jpg");
IplImage *img_blue = cvCreateImage(cvGetSize(img_in),IPL_DEPTH_8U,1);
IplImage *img_green = cvCreateImage(cvGetSize(img_in),IPL_DEPTH_8U,1);
IplImage *img_red = cvCreateImage(cvGetSize(img_in),IPL_DEPTH_8U,1);
IplImage *img_all = cvCreateImage(cvGetSize(img_in),IPL_DEPTH_8U,1);
IplImage *img_out = cvCreateImage(cvGetSize(img_in),IPL_DEPTH_8U,1);
IplImage *img_control = cvCreateImage(cvGetSize(img_in),IPL_DEPTH_8U,1);

void on_trackbar_1(int Threshold_pos)
{
	Threshold=Threshold_pos;
	cvSplit(img_in,img_blue,img_green,img_red,NULL);
	cvAddWeighted(img_blue,1.0/3,img_green,1.0/3,0.0,img_all);
	cvAddWeighted(img_all,2.0/3,img_red,1.0/3,0.0,img_all);
	cvThreshold(img_all,img_out,Threshold,Max_value,CV_THRESH_BINARY);
	cvThreshold(img_all,img_out,Threshold,Max_value,CV_THRESH_TRUNC);
	cvNamedWindow("img_out",CV_WINDOW_AUTOSIZE);
	cvShowImage("img_out",img_out);
}

void on_trackbar_2(int Max_value_pos)
{
	Max_value=Max_value_pos;
	cvSplit(img_in,img_blue,img_green,img_red,NULL);
	cvAddWeighted(img_blue,1.0/3,img_green,1.0/3,0.0,img_all);
	cvAddWeighted(img_all,2.0/3,img_red,1.0/3,0.0,img_all);
	cvThreshold(img_all,img_out,Threshold,Max_value,CV_THRESH_BINARY);
	cvNamedWindow("img_out",CV_WINDOW_AUTOSIZE);
	cvShowImage("img_out",img_out);
}

int main()
{
	cvNamedWindow("img_in",CV_WINDOW_AUTOSIZE);
	cvShowImage("img_in",img_in);

	cvSplit(img_in,img_blue,img_green,img_red,NULL);
	cvAddWeighted(img_blue,1.0/3,img_green,1.0/3,0.0,img_all);
	cvAddWeighted(img_all,2.0/3,img_red,1.0/3,0.0,img_all);

	cvNamedWindow("img_all",CV_WINDOW_AUTOSIZE);
	cvShowImage("img_all",img_all);

	cvNamedWindow("img_control",CV_WINDOW_AUTOSIZE);
	cvCreateTrackbar("Threshold","img_control",&t,255,on_trackbar_1);
	cvCreateTrackbar("Max_value","img_control",&t,255,on_trackbar_2);

	cvNamedWindow("img_out",CV_WINDOW_AUTOSIZE);

	cvWaitKey(0);
	cvDestroyAllWindows();
	cvReleaseImage(&img_in);
	cvReleaseImage(&img_blue);
	cvReleaseImage(&img_green);
	cvReleaseImage(&img_red);
	cvReleaseImage(&img_all);
	cvReleaseImage(&img_out);
	cvReleaseImage(&img_control);

	return 0; 
}

运行结果：

截断模式：

二值化模式：