《学习opencv》第四章课后习题2

// 4-2.cpp : 定义控制台应用程序的入口点。 // #include "stdafx.h" #include<opencv/cv.h> #include<opencv/highgui.h> int a,b; int showtext=0; void my_mouse_callback( int event, int x, int y, int flags, void* param ); void mouseHandler( int event, int x, int y, int flags, void* param ); // A litte subroutine to draw a box onto an image void showpiexl( IplImage* img,int x,int y) { char label[20]; sprintf(label,"(%d, %d, %d)",CV_IMAGE_ELEM(img, uchar, y, 3*x), CV_IMAGE_ELEM(img, uchar, y, 3*x+1),CV_IMAGE_ELEM(img, uchar, y, 3*x+2)); CvFont font; cvInitFont(&font, CV_FONT_VECTOR0,1, 1, 0, 1, 8); cvPutText(img,label,cvPoint(x,y),&font,CV_RGB(255,255,255)); cvShowImage("TEXT",img); } int main() { IplImage* img=cvLoadImage("C:\\lena.jpg"); cvNamedWindow("TEXT",CV_WINDOW_AUTOSIZE); cvSetMouseCallback("TEXT",my_mouse_callback,(void*)img); cvShowImage("TEXT",img); cvWaitKey(0); cvDestroyWindow("TEXT"); cvReleaseImage(&img); } void my_mouse_callback(int event, int x, int y, int flags, void* param ) { IplImage* img0; img0 = (IplImage*) param; //img1 = cvCloneImage(img0); switch( event ) { case CV_EVENT_LBUTTONDOWN: { showpiexl(img0,x,y); } break; } } void mouseHandler(int event, int x, int y, int flags, void* param) { IplImage* img0, * img1; CvFont font; uchar* ptr; char label[20]; img0 = (IplImage*) param; img1 = cvCloneImage(img0); cvInitFont(&font, CV_FONT_HERSHEY_PLAIN, .8, .8, 0, 1, 8); if (event == CV_EVENT_LBUTTONDOWN) { /* read pixel */ ptr = cvPtr2D(img1, y, x, NULL); /* * display the BGR value */ sprintf(label,"(%d, %d, %d)", ptr[0], ptr[1], ptr[2]); cvRectangle( img1, cvPoint(x, y - 12), cvPoint(x + 100, y + 4), CV_RGB(255, 0, 0), CV_FILLED, 8, 0 ); cvPutText( img1, label, cvPoint(x, y), &font, CV_RGB(255, 255, 0) ); cvShowImage("TEXT", img1); } }