帧差法和三帧差法

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我是靠谱客的博主称心绿草，最近开发中收集的这篇文章主要介绍帧差法和三帧差法，觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

帧差法

//取两帧图像
if(preSafetyRopeDetectionFrame.empty()){
     preSafetyRopeDetectionFrame = curFrame;//将第一帧赋给preFrame
     preSafetyRopeDetectionFrameIdx = detectTrackInfo.GetCurFrameIdx();
}
else{
     if((detectTrackInfo.GetCurFrameIdx() - preSafetyRopeDetectionFrameIdx) % 10 == 0){
         SafetyRopeDetection(curFrame, dressingCheckResultVec, eventOccur);//安全绳的检测实现
         preSafetyRopeDetectionFrame = curFrame;
         preSafetyRopeDetectionFrameIdx = detectTrackInfo.GetCurFrameIdx();
     }
}


//帧差法--未进行形态学处理（膨胀，边缘等操作）
cv::Mat frameROI = curFrame(detectSafetyRopeROI);   //取检测区域ROI
cv::Mat showImg = frameROI.clone();
cv::Mat preFrameROI = preSafetyRopeDetectionFrame(detectSafetyRopeROI);
cvtColor(frameROI, frameROI, cv::COLOR_BGR2GRAY); //转成灰度图
cvtColor(preFrameROI, preFrameROI, cv::COLOR_BGR2GRAY); //转成灰度图
cv::Mat cutframe;
absdiff(frameROI, preFrameROI, cutframe);  //图像做差
cv::imwrite("cha.jpg", cutframe);
cv::threshold(cutframe, cutframe, 100, 255, cv::THRESH_BINARY);  //二值化差值图像
cv::imwrite("2.jpg", cutframe);

三帧差法

//取三帧图像
if(preSafetyRopeDetectionFrame.empty()){
     preSafetyRopeDetectionFrame = curFrame;//将第一帧赋给preFrame
     preSafetyRopeDetectionFrameIdx = detectTrackInfo.GetCurFrameIdx();
}
else if(midSafetyRopeDetectionFrame.empty() && (detectTrackInfo.GetCurFrameIdx()- preSafetyRopeDetectionFrameIdx) % 20 == 0){
     midSafetyRopeDetectionFrame = curFrame;//将第一帧赋给preFrame
     midSafetyRopeDetectionFrameIdx = detectTrackInfo.GetCurFrameIdx();
}
else{
     if((midSafetyRopeDetectionFrameIdx - preSafetyRopeDetectionFrameIdx) % 20 == 0 && (detectTrackInfo.GetCurFrameIdx() - midSafetyRopeDetectionFrameIdx) % 20 == 0){    
          SafetyRopeDetection(curFrame, dressingCheckResultVec, eventOccur);//安全绳的检测实现
          preSafetyRopeDetectionFrame = midSafetyRopeDetectionFrame;
          preSafetyRopeDetectionFrameIdx = midSafetyRopeDetectionFrameIdx;
          midSafetyRopeDetectionFrame = curFrame;
          midSafetyRopeDetectionFrameIdx = detectTrackInfo.GetCurFrameIdx();
     }
}


//三帧差法
cv::Mat preFrameROI = preSafetyRopeDetectionFrame(detectSafetyRopeROI); //取检测挂线的ROI区域
cv::Mat midFrameROI = midSafetyRopeDetectionFrame(detectSafetyRopeROI);
cv::Mat frameROI = curFrame(detectSafetyRopeROI);
cv::Mat showImg = midFrameROI.clone();  //保留第二帧原图用于画线
cvtColor(preFrameROI, preFrameROI, cv::COLOR_BGR2GRAY); //转成灰度图
cvtColor(midFrameROI, midFrameROI, cv::COLOR_BGR2GRAY); //转成灰度图
cvtColor(frameROI, frameROI, cv::COLOR_BGR2GRAY); //转成灰度图
cv::Mat difframe1,difframe2,difframe3,cutframe;
absdiff(midFrameROI, preFrameROI, difframe1);//做差求绝对值   2-1
absdiff(midFrameROI, frameROI, difframe2);//做差求绝对值      2-3
bitwise_and(difframe1, difframe2, difframe3);  //做与运算
cv::imwrite("cha.jpg", difframe3);
cv::threshold(difframe3, cutframe, 100, 255, cv::THRESH_BINARY);  //二值化差值图像
cv::imwrite("2.jpg", cutframe);