《学习OpenCV》第八章轮廓课后题8.3

#include <iostream>
#include <opencv2/opencv.hpp>
#include <opencv2/highgui.hpp>

using namespace std;
using namespace cv;

#define CVX_RED   CV_RGB(0xff, 0x00, 0x00)
#define CVX_GREEN CV_RGB(0x00, 0xff, 0x00)
#define CVX_BLUE  CV_RGB(0x00, 0x00, 0xff)

void DrawBox(IplImage* img)
{
/*1、初始化相关变量*/
CvBox2D box ;
CvPoint2D32f center;
CvSize2D32f  size;
center.x = 50;
center.y = 50;
size.width = 30;
size.height = 30;
box.center = center;
box.size = size;
CvPoint2D32f point[4];
int i;
for ( i=0; i<4; i++)
{
point[i].x = 0;
point[i].y = 0;
}

/*2、计算CvBox2D结构表示矩形的4顶点*/
cvBoxPoints(box, point); //计算二维盒子顶点，把box的点赋值给point

/*3、把float类型的点转化成int类型*/
CvPoint pt[4];
for ( i=0; i<4; i++)
{
pt[i].x = (int)point[i].x;
pt[i].y = (int)point[i].y;
}

/*4、开辟一个内存管理器并创建一个序列*/
CvMemStorage* store = cvCreateMemStorage(0);
CvSeq* seq = cvCreateSeq(CV_SEQ_ELTYPE_POINT | CV_SEQ_KIND_CURVE | CV_SEQ_FLAG_CLOSED,sizeof(CvContour),sizeof(CvPoint),store);

/*5、数据的存储和提取*/
for (int j = 0; j < 4; j++)
{
cvSeqPush(seq,&pt[j]);
}
for (int j = 0; j < seq->total; j++)
{
CvPoint* p=(CvPoint*)cvGetSeqElem(seq,j);
printf("p->x=%d,p->y=%d\n",p->x,p->y);
}

/*6、绘制图形*/
cvDrawContours(img,seq,CV_RGB(255,255,255),CV_RGB(255,255,255),1,3,8);
cvShowImage("Box", img);
cvReleaseMemStorage(&store);
}

void DrawCircle(IplImage* img)
{
/*1、开辟一个内存管理器并创建一个序列*/
CvMemStorage* store = cvCreateMemStorage(0);
CvSeq* seq = cvCreateSeq(CV_SEQ_ELTYPE_POINT | CV_SEQ_KIND_CURVE |CV_SEQ_FLAG_CLOSED,sizeof(CvContour),sizeof(CvPoint),store);

/*2、绘制圆*/
CvPoint pt;
for(int x=25; x<25+50; x++)
{
float y = 50 + sqrt(25*25.0-(x-50)*(x-50));

pt.x = x;
pt.y = y;
cvSeqPush(seq,&pt);
}
for(int x=25+50; x>25; x--)
{
float y = 50 - sqrt(25*25.0-(x-50)*(x-50));
pt.x = x;
pt.y = y;
cvSeqPush(seq,&pt);
}

for (int j = 0; j < seq->total; j++)
{
CvPoint* p=(CvPoint*)cvGetSeqElem(seq,j);
printf("p->x=%d,p->y=%d\n",p->x,p->y);
}
cvDrawContours(img,seq,CV_RGB(255,255,255),CV_RGB(255,255,255),1,3,8);
cvShowImage("Circle", img);
cvReleaseMemStorage(&store);
}

int main()
{
/*1、申请内存、创建一个图片、*/
CvMemStorage* storage = cvCreateMemStorage();
IplImage* img = cvCreateImage(cvSize(200,200),8,3);
cvZero(img);
cvShowImage("img", img);

/*2、绘制矩形*/
DrawBox(img);
cvSetZero(img);

/*3、绘制圆*/
DrawCircle(img);
cvWaitKey(100000);

cvReleaseImage(&img);
cvReleaseMemStorage(&storage);
return 1;
}