opencv提取截獲影象(總結摘來)
阿新 • • 發佈:2019-01-01
擷取
100*100的矩陣頭
CvRect rect = cvRect(0, 0, 100, 100); //要擷取的區域,與建立的矩陣大小一樣
cvGetSubRect(pImg, pMat, rect); //pImg為指向影象的指標,pMat指向儲存所接影象的矩陣,返回值和pMat相等
也可以簡化為:
CvMat *pMat = cvGetSubRect(pImg, cvCreateMatHeader(100, 100, CV_8UC1), cvRect(0, 0, 100, 100));
第二步,把剛才存入矩陣的資料轉存為影象。
Rect rect(10, 20, 100, 50);
Mat image_roi = image(rect);
分割/聚合顏色平面
split( );
merge( );
案例一、得到由矩形提取到的影象
第一步,把擷取影象中需要的區域存入矩陣。
CvMat* cvGetSubRect(const CvArr* arr, CvMat* submat, CvRect rect);
把IplImage *傳給arr,IplImage *指向所要擷取的影象;
把CvMat *傳給submat;
rect是要擷取的區域;
返回指向所存矩陣。
例如:
CvMat *pMat = cvCreateMatHeader(100, 100, CV_8UC1); //建立一個
CvRect rect = cvRect(0, 0, 100, 100); //要擷取的區域,與建立的矩陣大小一樣
cvGetSubRect(pImg, pMat, rect); //pImg為指向影象的指標,pMat指向儲存所接影象的矩陣,返回值和pMat相等
也可以簡化為:
CvMat *pMat = cvGetSubRect(pImg, cvCreateMatHeader(100, 100, CV_8UC1), cvRect(0, 0, 100, 100));
第二步,把剛才存入矩陣的資料轉存為影象。
IplImage* cvGetImage( const CvArr* arr, IplImage* image_header );
把CvMat *傳給arr;image_header;
只需為影象頭就行,不用分配資料儲存空間 ;
返回所存影象的指標。
例如:
IplImage *pSubImg = cvCreateImageHeader(cvSize(100, 100), 8, 1); //建立一個100*100的影象頭
cvGetImage(pMat, pSubImg); //pMat為儲存資料的矩陣,pSubImg指向影象,返回值與pSubImg相等
也可以簡化為:
IplImage *pSubImg = cvGetImage(pMat, cvCreateImageHeader(cvSize(100, 100), 8, 1));
案例二、得到任意形狀區域
第一步、在圖片上畫出來
#include "cv.h"
#include "highgui.h"
#include <stdio.h>
#include <stdlib.h>
IplImage* inpaint_mask = 0;
IplImage* img0 = 0, *img = 0, *inpainted = 0;
CvPoint prev_pt = {-1,-1};
void on_mouse( int event, int x, int y, int flags, void* zhang)
{
if( !img )
return;
if( event == CV_EVENT_LBUTTONUP || !(flags & CV_EVENT_FLAG_LBUTTON) )
prev_pt = cvPoint(-1,-1);//初始化
else if( event == CV_EVENT_LBUTTONDOWN )
prev_pt = cvPoint(x,y);
else if( event == CV_EVENT_MOUSEMOVE && (flags & CV_EVENT_FLAG_LBUTTON) )
{//手一直在繪畫
CvPoint pt = cvPoint(x,y);
if( prev_pt.x < 0 )
prev_pt = pt;
cvLine( inpaint_mask, prev_pt, pt, cvScalarAll(255), 5, 8, 0 );
cvLine( img, prev_pt, pt, cvScalarAll(255), 5, 8, 0 );
prev_pt = pt;
cvShowImage( "image", img );
}
}
int main( int argc, char** argv )
{
char* filename = argc >= 2 ? argv[1] : (char*)"fruits.jpg";
if( (img0 = cvLoadImage(filename,-1)) == 0 )
return 0;
printf( "Hot keys: \n"
cvNamedWindow( "image", 1 );
img = cvCloneImage( img0 );
inpainted = cvCloneImage( img0 );
inpaint_mask = cvCreateImage( cvGetSize(img), 8, 1 );
cvZero( inpaint_mask );
cvZero( inpainted );
cvShowImage( "image", img );
cvShowImage( "watershed transform", inpainted );
cvSetMouseCallback( "image", on_mouse, 0 );
}
第二步、將選擇的區域提取出來
if(event == CV_EVENT_RBUTTONUP)
{
cvFloodFill(maskImg,cvPoint(x,y),cvScalarAll(255));
cvSaveImage("maskImg.bmp",maskImg);
IplImage *segImage=cvCreateImage(cvGetSize(img),8,3);;
cvCopy(img,segImage,maskImg);
cvSaveImage("segImage.bmp",segImage);
cvCopy(segImage,proc->img);
cvReleaseImage(&segImage);
cvDestroyWindow("Key Image");
}