OpenCV鼠标画图例程，鼠标绘制矩形

最新推荐文章于 2020-09-24 21:53:41 发布

转载最新推荐文章于 2020-09-24 21:53:41 发布 · 363 阅读

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本文提供了一个使用OpenCV库进行鼠标交互绘制矩形的示例程序。通过安装回调函数来响应用户的鼠标操作，实现动态绘制矩形框的功能。

文章出处来源于：

http://blog.youkuaiyun.com/wangyaninglm/article/details/19618871

#include <cv.h>

#include <highgui.h>
#pragma comment(lib,"opencv_core2413d.lib") //等同于附加依赖项所需的库文件

#pragma comment(lib,"opencv_highgui2413d.lib")

/*
zlibd.lib
libjasperd.lib
libjpegd.lib
libpngd.lib
libtiffd.lib
vfw32.lib
comctl32.lib
IlmImf.lib
gdi32.lib
*/
//以下代码经过测试可用
// Define our callback which we will install for
// mouse events.
//
void my_mouse_callback(int event, int x, int y, int flags, void* param);

CvRect box;
bool drawing_box = false;

// A litte subroutine to draw a box onto an image
//
void draw_box(IplImage* img, CvRect rect)
{
cvRectangle
(
img,
cvPoint(box.x, box.y),
cvPoint(box.x + box.width, box.y + box.height),
cvScalar(0x00, 0x00, 0xff) /* red */
);
}

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");

// Here is the crucial moment that we actually install
// the callback. Note that we set the value ‘param’ to
// be the image we are working with so that the callback
// will have the image to edit.
//
cvSetMouseCallback(
"Box Example",
my_mouse_callback,
(void*)image
);

// The main program loop. Here we copy the working image
// to the ‘temp’ image, and if the user is drawing, then
// put the currently contemplated box onto that temp image.
// display the temp image, and wait 15ms for a keystroke,
// then repeat…
//
while (1) {

cvCopyImage(image, temp);
if (drawing_box) draw_box(temp, box);
cvShowImage("Box Example", temp);

if (cvWaitKey(15) == 27) break;
}

// Be tidy
//
cvReleaseImage(&image);
cvReleaseImage(&temp);
cvDestroyWindow("Box Example");
}

// This is our mouse callback. If the user
// presses the left button, we start a box.
// when the user releases that button, then we
// add the box to the current image. When the
// mouse is dragged (with the button down) we
// resize the box.
//
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;
}
}