calcopticalflowpyrlk斷言失敗

Question

我試圖做視頻穩定在OpenCV的2.4.12在Ubuntu下面的代碼，我使用calcopticalflowpyrlk會拋出一個斷言失敗錯誤： 錯誤是以下幾點：

OpenCV的錯誤：斷言失敗（（npoints = prevPtsMat.checkVector（2，CV_32F，true））> = 0）in cv :: calcOpticalFlowPyrLK，file home ... \ opencv \ modules \ video \ src \ lkpyramid.cpp，line 845

這裏是代碼：

#include <stdio.h> 
#include <sys/types.h> 
#include <unistd.h> 
#include <sys/stat.h> 
#include <fcntl.h> 
#include <errno.h> 
#include <iostream> 
#include <stdlib.h> 

#include <opencv2/opencv.hpp> 
#include <opencv2/core/core.hpp> 
#include <opencv2/highgui/highgui.hpp> 
#include <opencv2/imgproc/imgproc.hpp> 


using namespace cv; 
using namespace std; 




int main() 
{ 

int rows = 240; 
int cols = 240; 
int i = 1; 

VideoCapture cap(0); 

Mat Canvass; 
Canvass.create(rows, cols * 2, CV_8UC3); 




for(;;) 
{Mat prev,cur; 

    Mat prev_gray,cur_gray, aligned; 
    Mat TT(2, 3, CV_64F); 

    vector <Point2f> cur_corner, cur_corner2, prev_corner2; 
    vector <Point2f> prev_corner; 
    Mat prev_grey; 
    vector <uchar> status; 
    vector <float> err; 
    double dx, dy, da; 

    const int max_no_of_corners = 20000; 
    const double quality_of_corners = 0.00001; 
    const double min_dist_bw_corners = 5; 
    const int search_window_size = 80; 
    const int pyramid_level = 5; 

Mat cur_warped; 
int rows = 240; 
int cols = 240; 


    if(i == 1) 
    { //capture the prev frame,resize,grayscale and display it 
      for (int x = 0; x < 10;x++) 
      { cap >> prev; } 

     resize(prev, prev,Size(240,240)); 
     cvtColor(prev,prev_gray,CV_BGR2GRAY); 
     prev.copyTo(Canvass(Range::all(), Range(0,cols))); 
       //capture the current frame,resize and grayscale it 
     cap>>cur; 
     resize(cur,cur,Size(240,240)); 
     cvtColor(cur,cur_gray,CV_BGR2GRAY); 
     i++; 
    } 
    else{ 
      cap>>cur; 
      resize(cur,cur,Size(240,240)); 
      cvtColor(cur,cur_gray,CV_BGR2GRAY); 
      cvtColor(prev,prev_gray,CV_BGR2GRAY); 
      //display the previous image in canvass 
      cur.copyTo(Canvass(Range::all(), Range(0,cols))); 

    } 

      ///find corner points here 

goodFeaturesToTrack(prev_grey, prev_corner, max_no_of_corners, quality_of_corners, min_dist_bw_corners); 

    //usecalcopticalflowpyrlk 
calcOpticalFlowPyrLK(prev_gray, cur_gray, prev_corner, cur_corner, status, err, Size(10,10),2); 

//weed out bad matches 
for (int t = 0; t < status.size(); t++) { 
     if (int(status[t])) { 

      cur_corner2.push_back(cur_corner[t]); 
      prev_corner2.push_back(prev_corner[t]); 
     } 
    } 



    //estimate transform 
Mat T; 
T = estimateRigidTransform(prev_corner2, cur_corner2,false); 

if (T.data == NULL) 
{cout<<"No transform found"<<endl; 
     cur.copyTo(Canvass(Range::all(), Range(cols,cols * 2))); 
     cur.copyTo(prev); 
     } 
    else{ 
        cout<<"transform found "<<endl; 
     // decompose T 
     dx = T.at<double>(0, 2); 
     dy = T.at<double>(1, 2); 
     da = atan2(T.at<double>(1, 0), T.at<double>(0, 0)); 
     da = -da; 
     //da = 0; 
     TT.at<double>(0, 0) = cos(da);; 
     TT.at<double>(0, 1) = -sin(da); 
     TT.at<double>(1, 0) = sin(da); 
     TT.at<double>(1, 1) = cos(da); 
     TT.at<double>(0, 2) = -dx;///scale; 
     TT.at<double>(1, 2) = -dy;///scale; 
     //TT.copyTo(Transform); 

//warp 
warpAffine(cur, cur_warped, TT, cur.size(),INTER_NEAREST|WARP_INVERSE_MAP); 
cur.copyTo(prev); 
cur_warped.copyTo(Canvass(Range::all(), Range(cols,(cols * 2)))); 
} 

imshow("Output",Canvass); 
waitKey(1); 
} 

} 

我認爲在calcopticalflowpyrlk中可能存在一些向量數據類型的問題，但我已經用文檔驗證過它們，但仍然遇到了這個錯誤。我該如何解決這個問題？

Answer 1

您能顯示並檢查prev_corner.size()和cur_corner.size()嗎？據斷言這些載體似乎是空的。如果是這種情況 - 只需檢查是否有足夠的特徵點來尋找對應關係。

順便說一句，您還應該在調用estimateRigidTransform()之前檢查匹配數量;如果我記得正確 - 它至少需要3個對應關係（估計6個自由度）。