图像二值化后为什么背景的颜色为白色？此前使用的时候背景的颜色都为黑色的

brk1985 2009-07-19 10:07:38

使用OpenCV图像二值化函数cvThreshold，之前一直为黑色，但是我从网上下载的一个代码，也是用cvThreshold函数，看了关键代码也差不多。但是二值化后背景的颜色确是白色，为什么呢？



#include "cv.h"

#include "highgui.h"

#include <stdio.h>



int slider_pos = 40;



IplImage *image02 = 0, *image_src = 0, *image04 = 0;

void process_rect(int h);



void main( int argc, char** argv )

{

    const char* filename = "E:\\106vd.bmp";

    

    // 读入图像，强制为灰度图像

    if( (image_src = cvLoadImage(filename, 1)) == 0 ) //cvLoadImage(filename, 1)则为单通道图像

        return;



    // Create the destination images

    //image02 = cvCloneImage( image_src );

    //image04 = cvCloneImage( image_src );

	image02 = cvCreateImage(cvGetSize(image_src),8,1);//8位单通道图片

	image04 = cvCreateImage(cvGetSize(image_src),8,1);//8位单通道图片 NULL array pointer is passed

	cvCvtColor(image_src,image02,CV_BGR2GRAY);

	cvSmooth(image02, image02, CV_GAUSSIAN,9,9);//去除干扰

	cvErode( image02, image02, NULL,1 );//3*3腐蚀模板过滤，以去掉零星的噪声  		

	cvDilate(image02, image02, 0, 1);//3*3膨胀模板过滤，以恢复原来的前景

	//image02 = cvCloneImage( image_src );



    // Create windows.

    cvNamedWindow("Source", 1);

    cvNamedWindow("Result", 1);





    // Create toolbars. HighGUI use.

    cvCreateTrackbar( "Threshold", "Result", &slider_pos, 255, process_rect );

    process_rect(0);



    // Show the image.

    cvShowImage("Source", image_src);

	//cvShowImage("Result", image02);

    // Wait for a key stroke; the same function arranges events processing                

    cvWaitKey(0);



    cvReleaseImage(&image02);

    cvReleaseImage(&image_src);



    cvDestroyWindow("Source");

    cvDestroyWindow("Result");

}



// Define trackbar callback functon. This function find contours,

// draw it and approximate it by ellipses.

static void process_rect(int h)

{

 

    // 创建动态结构序列

    CvMemStorage* stor = cvCreateMemStorage(0);

    CvSeq* cont = cvCreateSeq(CV_SEQ_ELTYPE_POINT, sizeof(CvSeq), sizeof(CvPoint) , stor);



    

    // 二值化图像.

	//slider_pos = Otsu(image02);

	//char str[50];

	//sprintf(str,"%d",slider_pos);

	//MessageBox( 0, str , ".net", 0 );



    cvThreshold( image02, image04, slider_pos, 255, CV_THRESH_BINARY );



    // Show image. HighGUI use.

    cvShowImage( "Result", image04 );/**/

}