Zi 字媒體

fanfuhan OpenCV 教學086 ~ opencv-086-視頻分析(稠密光流分析) 資料來源: https://fanfuhan.github.io/ https://fanfuhan.github.io/2019/05/06/opencv-086/ GITHUB:https://github.com/jash-git/fanfuhan_ML_OpenCV 光流跟踪方法分為稠密光流跟踪與稀疏光流跟踪算法，KLT是稀疏光流跟踪算法，前面我們已經介紹過了，OpenCV還支持稠密光流的移動對象跟踪方法，OpenCV中支持的稠密光流算法是由Gunner Farneback在2003年提出來的，它是基於前後兩幀所有像素點的移動估算算法，其效果要比稀疏光流算法更好。 C++ Python import cv2 as cv import numpy as np cap = cv.VideoCapture("D:/images/video/vtest.avi") ret, frame1 = cap.read() prvs = cv.cvtColor(frame1,cv.COLOR_BGR2GRAY) hsv = np.zeros_like(frame1) hsv[...,1] = 255 while(1): ret, frame2 = cap.read() next = cv.cvtColor(frame2,cv.COLOR_BGR2GRAY) flow = cv.calcOpticalFlowFarneback(prvs,next, None, 0.5, 3, 15, 3, 5, 1.2, 0) mag, ang = cv.cartToPolar(flow[...,0], flow[...,1]) hsv[...,0] = ang*180/np.pi/2 hsv[...,2] = cv.normalize(mag,None,0,255,cv.NORM_MINMAX) bgr = cv.cvtColor(hsv,cv.COLOR_HSV2BGR) cv.imshow('frame2',bgr) k = cv.waitKey(30) & 0xff if k == 27: break elif k == ord('s'): cv.imwrite('opticalfb.png',frame2) cv.imwrite('opticalhsv.png',bgr) prvs = next cap.release() cv.destroyAllWindows()