学习 Opencv 例 4-1 正确跑出运行结果

把书上代码中的 cvCopyImage 函数改为 cvCopy 函数

代码：

#include 
#include 
#include 
#include 

using namespace std;
using namespace cv;

CvRect box;
bool drawing_box = false;

void draw_box(IplImage* img, CvRect rect)
{
    cvRectangle(
                img,
                cvPoint(box.x, box.y),
                cvPoint(box.x + box.width, box.y + box.height),
                cvScalar(0xff, 0x00, 0x00)
                );
}

void my_mouse_callback(int event, int x, int y, int flags, void* param)
{
    IplImage* image = (IplImage*) param;
    switch(event)
    {
        case CV_EVENT_MOUSEMOVE:
        {
            if (drawing_box)
            {
                box.width = x - box.x;
                box.height = y - box.y;
            }
        }
            break;
        case CV_EVENT_LBUTTONDOWN:
        {
            drawing_box = true;
            box = CvRect(x, y, 0, 0);
        }
            break;
        case CV_EVENT_LBUTTONUP:
        {
            drawing_box = false;
            if (box.width < 0)
            {
                box.x += box.width;
                box.width *= -1;
            }
            if (box.height < 0)
            {
                box.y += box.height;
                box.height *= -1;
            }
            draw_box(image, box);
        }
            break;
    }
}

int main(int argc, char* argv[])
{
    box = CvRect(-1, -1, 0, 0);
    
    IplImage* image = cvCreateImage(cvSize(200, 200), IPL_DEPTH_8U, 3);
    
    cvZero(image);
    
    IplImage* temp = cvCloneImage(image);
    
    cvNamedWindow("Box Example");
    
    cvSetMouseCallback(
                       "Box Example",
                       my_mouse_callback,
                       (void*) image
                       );
    
    while(1)
    {
        cvCopy(image, temp);
        if (drawing_box)
        {
            draw_box(temp, box);
        }
        cvShowImage("Box Example", temp);
        if (cvWaitKey(15) == 27)
        {
            break;
        }
    }
    
    cvReleaseImage(&image);
    cvReleaseImage(&temp);
    cvDestroyWindow("Box Example");
    
    return 0;
}

运行结果截图：