cvZero()；是让矩阵的值都为0，有初始化的作用，或者说清零~
比如说：IplImage img=cvCreateImage(cvSize(640,480),IPL_DEPTH_8U,1);%创建一幅图像
cvZero(img);%相当于初始化图片，值都为0，矩阵大小为640*480
cvShowImage("img",img);%就显示一幅黑色，且值都为零的图像
cvCircle(CvArr* img , CvPoint center , int radius , CvScalar color , int thickness=1 , int lineType=8 , int shift=0 )
img为图像指针，单通道多通道都行，不需要特殊要求
center为画圆的圆心坐标
radius为圆的半径
color为设定圆的颜色，比如用CV_RGB(255, 0,0)设置为红色
thickness为设置圆线条的粗细，值越大则线条越粗，为负数则是填充效果
1:
#include
"stdafx.h"
2:
#include
"opencv2/opencv.hpp"
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#include
"opencv2/opencv_modules.hpp"
4:
#include
"cv.h"
5:
#include
"cxcore.h"
6:
#include
"highgui.h"
7:
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#define
RaderImageWdith 720
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#define
RaderImageHeight 720
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/*******************从文件中读取一副图像并在屏幕中显示***********************/
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int
main()
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{
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/*********************雷达数据处理*********************/
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IplImage* RaderImage = cvCreateImage(cvSize(RaderImageWdith,RaderImageHeight),IPL_DEPTH_8U,1);
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cvZero(RaderImage);
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int
dx = RaderImageWdith/2;
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int
dy = RaderImageHeight*3/4;
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cvCircle(RaderImage, cvPoint(dx,dy),3, CV_RGB(0,255,255), -1, 8,0);
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cvShowImage(
"RaderImage"
,RaderImage);
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//定义一个字符指针，并指向图片所在的位置
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char
*PFileName;
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PFileName =
"D:\\Pictures\\parrot.jpg"
;
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//读取一张图片并载入内存，并用一个数据结构指针指向这张图片
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IplImage *Img = cvLoadImage(PFileName);
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if
(NULL == Img)
//如果读入失败，退出程序
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exit(1);
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//创建一个窗体，标题为Example，自增益
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cvNamedWindow(
"Example"
,1);
39:
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//用指针指向图像的数据区头部
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uchar *pchar;
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int
width = Img ->width;
//读取图像宽度
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int
height = Img ->height;
//读取图像高度
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int
channel = Img ->nChannels;
//读取图像的通道数
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int
widthStep = Img ->widthStep;
//读取图像一行像素所占的字节数
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int
i,j;
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for
(i = 0; i < height ; i++)
//以下是遍历一副图像中的每个像素点
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{
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pchar = (uchar*)Img ->imageData + i * widthStep;
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for
(j = 0; j < width; j++)
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{
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uchar *temp = pchar + j * channel;
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temp[0] += 10;
//通道B
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temp[1] += 10;
//通道G
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temp[2] += 10;
//通道R
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}
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}
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//在窗口中显示这张图片
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cvShowImage(
"Example"
,Img);
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//暂停程序，等待用户触发一个按键
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cvWaitKey(0);
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//释放图像所分配的内存空间
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cvReleaseImage(&Img);
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//销毁窗口
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cvDestroyWindow(
"Example"
);
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return
0;
67:
}
