opencv学习心得

Opencv学习（二）

1.    函数命名

cvAction(表示核心函数Set,Create)Target(图像区域)Mod（变量类型）

矩阵函数类型

通用CV_<bit_depth>(S|U|F)C<number_of_channels>

S:符号整数

U：无符号整数

F：浮点数

CV_8UC1 8位无符号整数单通道矩阵

图像数据类型

 IPL_DEPTH_32F  表示32位浮点数图像

CVPoint p=cvPoint(int x,int y);

CVPoint2D32f p=cvPoint2D32f(float x,float y);

CVSize  r=cvSize(int width,int height);

CVRect r=cvRect(intx,int y,int width,int height);

分配矩阵

CvMat*cvCreateMat(int rows,int cols,inttype);

 

CvMat*M=cvCreateMat(4,4,CV_32FC1);

cvReleaseMat(&M);

CvMat*cvCloneMat(CvMat*);复制矩阵。

CvMat*M1=cvCreateMat(4,4CV_32FC1);

CvMat*M2;

M2=cvCloneMat(M1);

初始化矩阵

Double a[ ]={1,2,3,4,

            5,6,7,8,

            9,10,11,12};

CvMatMa=cvMat(3,4,CV_64FC1,a);或；

CvMat Ma;

cvintMatHeader(&Ma,3,4,CV_64FC1,a);

访问矩阵

1.    直接访问

cvmSet(M,i,j,2,0);M(I,j)赋值

       t=cvmGet(M,I,j);

已知对齐方式的直接访问：

      CvMat*M =cvCreateMat (4,4,CV_32FC1);

      Int n =M->cols;

      Float *data =M->data.fl;

      Data[ i*n+j]=3.0;

未知对齐方式的直接访问

CvMat*M =cvCreateMat (4,4,CV_32FC1);

Int step =M->step/sizeof/(float);

Float *data =M->data.fl;

(data+i*step)[j]=3.0;

直接访问一个已知初始化的矩阵

   Double a[16];

   CvMat Ma=cvMat(3,4,CV_64FCI,a);

A[i*4+j]=2.0

 

 

GUI命令

  创建定位一个窗口：

 cvNameWindow(“win1”,CV_WINDOW_AUTOSIZE);

cvMoveWindow(“win1”,100,100);

加载一幅图片

IplImage*img=0;

Img=cvLoadImage(fileName);

If(!img)printf(“Could not load image file:%s\n”,fileName);

显示一幅图像

cvShowImage(“win1”,img);

关闭窗口

cvDestroyWindow(“win1”);

缩放窗口

cvResizeWindow(“win1”,100,100);

      分配一幅图像

       IpIImage*img1=cvCreatImage(cvSize(640,480),IPL_DEPTH_8U,1);

      cvReleseImage(&img);//释放一幅图像

       IpIImage*img2;

Img2=cvCloneImage(img 1);

读入图像文件，先进行图像反转，然后将图像显示在屏幕上。

#include<stdlib.h>

#include<stdio.h>

#include<math.h>

#include<cv.h>

#include<highgui.h>

int main(intargc,char *argv[])

{

   IplImage*img = 0;

   int height, width,step, channels;

   uchar *data;

   int i, j, k;

   if (argc < 2)

   {

       printf("Usage：InvImage<image-file-name>\n\7");

       exit(0);

   }

   img= cvLoadImage(argv[1]);

   if (!img)

   {

       printf("Could not load image file:%s\n",argv[1]);

       exit(0);

   }

    height= img->height;

   width= img->width;

   step= img->widthStep;

   channels= img->nChannels;

   data= (uchar*)img->imageData;

   printf("Processing a%dx%d image with %d channels\n", height, width, channels);

   cvNamedWindow("mainWin",CV_WINDOW_AUTOSIZE);

   cvMoveWindow("mainWin", 100,100);

   for (i = 0; i <height; i++)for (j = 0;j < width; j++) for (k = 0; k <channels; k++);

   data[i*step+ j*channels + k] = 255 - data[i*step + channels + k];

   cvShowImage("mainWin", img);

   cvWaitKey(30);

   cvReleaseImage(&img);

   return 0;

 

}

从文件中读取图像

IplImage*img=0;

Img=cvLoadImage(filename);

If(!img)printf(“could not load image file:%s\n”,filename);

 

调整默认设置（3-通道）

Img=cvLoadImage,(filename,flag);>0(3通道)=0(单通道灰度图像)<0（图像的通道数决定）；

向文件写图像：

If(!cvSeveImage(outFileName,img))

 Printf(“Couldnot save:%s\n”,outFilename);

图片格式转换：

#include<cv.h>

#include<highgui.h>

#include<stdio.h>

int main(intargc,char**argv)

{

   IplImage *src;

   if (argc != 3)

   {

       printf("CONV:Image format convertion,supportJPG,BMP,TIE,PNG,PPM\n");

       printf("Usage:conv srcImage dstImage\n");

       return 0;

   }

   if (strstr(argv[1],".jpg")==NULL

       &&strstr(argv[1],".bmp") ==NULL

       &&strstr(argv[1],".tif") ==NULL

       &&strstr(argv[1],".png") ==NULL

       &&strstr(argv[1],".ppm") ==NULL)

       ||(strstr(argv[2], ".jpg") ==NULL

            &&strstr(argv[2],".bmp") ==NULL

            &&strstr(argv[2],".tif") ==NULL

            &&strstr(argv[2],".png") ==NULL

            &&strstr(argv[2],".ppm") ==NULL

            ))

   {

       printf("WARNING:CONV only suportJPG,BMP,TIF.PPM.TAG,andPPM\n");

   }

   else

   {

       if ((src =cvLoadImage(argv[1],-1)) != 0){

            cvSaveImage(argv[2], src);

            cvReleaseImage(&src);

            printf("\n Convert succeesfully.\n");

       }

       else {

            printf("\n*** Read or write image Fils***\n");

       }

   }

   return 0;

}

 

 

访问图片元素

 间接访问：

 IplImage*img=cvCreateImage(cvSize(640,480),IPL_DEPTH_8U,1);

CVScalar s;

S=cvGet2D(img,ij);

Printf(“intensity=%f\n”,s.val[0]);

s.val{0}=111;

cvSet2D(img,ij,s);

 

间接访问：

（（uchar*）(img->imageData+i*img->widthStep)）[j]=111;

多通道

（（uchar*）(img->imageData+i*img->widthstep)）[j*img->nChannels+0]=111;BGR

（（uchar*）(img->imageData+i*img->widthstep)）[j*img->nChannels+1]=112;

（（uchar*）(img->imageData+i*img->widthstep)）[j*img->nChannels+2]=113;

多通道浮点数用float*

指针直接访问;

Int height =img->height;

Int width=->img->width;

Int step=->img->widthStep/sizeof(unchar);

Uchar*data (uchar*)img->imageData;

Data[i*step+j]=111;

多通道   int channels= img ->nChannels;

Data[i*step+j*channels+k]=111;

将灰度图像转换成彩色图像

CvConvertImage(src,dst,flags=0);

 浮点（单字节灰度（彩色）图像）；

 Flags   CV_CVTIMG_FLIP.垂直翻转   CV_CVTIMG_SWAP_RB   交换R和B通道。。

彩色转换为灰色

 CvCvtColor(cimg,gimg.CV_BGR2GRAY);

 

 

画矩形

    cvRectangle(img,cvPoint(100,100),cvPoint(200,200),CVScalar(255,0,0),1);

画圆形

    CvCircle(img,cvPoint(100,100),20,cvScalar(0,255,0),1);

画线段

    cvLine(img,cvPoint(100，100) ,cvPoint(200,200),CVScalar(255,0,0),1);

画多边形

 

 

 

视屏的使用和操作

一．捕获某一帧

IpImage*img =0;

If(！cvGrabFrame(capture)){

 Printf(“Could notgrab a frame\n\7”);

Exit(0);

}

保存视屏文件

      初始化视频写入

对视屏写入并初始化

  CvvideoWriter*writer=0;

  Int isColor=1;

Int fps=25;

Int frameW=640;

Int frameH=480;

Writer=cvCreateVideoWriter(“out”)

CvtSeqToArray

CvMemStorage *stor;

CvSeq*cont;

CvPoint *PointArray;

CvPoint2D32f*PointArray2D32f;

Float temp;

Stor=cvCreateMemStorage(0);

Cont=cvCreateSeq(CV_SEQ_ELTYPE_POINT,sizeof(CvSeq),sizeof(CvPoint),stor);

 

CvFlushSeq Writer