使用OpenCV消除閃爍？

Question

我是openCV的新手。我已經在ubuntu系統上安裝了opencv庫，對它進行了編譯並嘗試在opencv中查看一些圖像/視頻處理應用程序以瞭解更多信息。

我很想知道OpenCV庫是否有捕獲視頻中的閃爍算法/類？如果是的話，我應該更深入地研究哪些文件或代碼？

如果openCV沒有它，在其他一些視頻處理庫/ SDK/Matlab中是否有任何標準實現，它們提供了從視頻序列中去除閃爍的算法？

任何指針都會有用

謝謝。

-AD。

Answer 1

我不知道任何標準的方法來使視頻閃爍。

但VirtualDub是一個視頻處理軟件，它有一個用於deflickering視頻的過濾器。你可以找到它的過濾源和文檔（可能是算法描述）here。

Answer 2

我寫了我自己的Deflicker C++函數。這裏是。您可以按原樣剪切和粘貼此代碼 - 除了常用的openCV以外，不需要任何頭文件。

Mat deflicker(Mat,int); 
    Mat prevdeflicker; 
    Mat deflicker(Mat Mat1,int strengthcutoff = 20){ //deflicker - compares each pixel of the frame to a previously stored frame, and throttle small changes in pixels (flicker) 

    if (prevdeflicker.rows){//check if we stored a previous frame of this name.//if not, theres nothing we can do. clone and exit 
     int i,j; 
     uchar* p; 
     uchar* prevp; 
     for(i = 0; i < Mat1.rows; ++i) 
     { 
      p = Mat1.ptr<uchar>(i); 
      prevp = prevdeflicker.ptr<uchar>(i); 
      for (j = 0; j < Mat1.cols; ++j){ 

       Scalar previntensity = prevp[j]; 
       Scalar intensity = p[j]; 
       int strength = abs(intensity.val[0] - previntensity.val[0]); 

       if(strength < strengthcutoff){ //the strength of the stimulus must be greater than a certain point, else we do not want to allow the change 
        //value 25 works good for medium+ light. anything higher creates too much blur around moving objects. 
        //in low light however this makes it worse, since low light seems to increase contrasts in flicker - some flickers go from 0 to 255 and back. :(
        //I need to write a way to track large group movements vs small pixels, and only filter out the small pixel stuff. maybe blur first? 

        if(intensity.val[0] > previntensity.val[0]){ // use the previous frames value. Change it by +1 - slow enough to not be noticable flicker 
         p[j] = previntensity.val[0] + 1; 
        }else{ 
         p[j] = previntensity.val[0] - 1; 
        } 
       } 

      } 

     }//end for 
    } 

    prevdeflicker = Mat1.clone();//clone the current one as the old one. 
    return Mat1; 
} 

將其稱爲：Mat = deflicker（Mat）。它需要一個循環和一個灰度圖像，如下所示：

for(;;){ 
    cap >> frame; // get a new frame from camera 
    cvtColor(frame, src_grey, CV_RGB2GRAY); //convert to greyscale - simplifies everything 

    src_grey = deflicker(src_grey); // this is the function call 

    imshow("grey video", src_grey); 
    if(waitKey(30) >= 0) break; 
}