Python Lucas Kanade光流实现工作不正常

我正在使用python和numpy编写自己的光流脚本。但是，我使用该算法（）的opencv实现获得的流结果与我自己的不同

这是我的完整代码：

import cv2
import numpy as np

def drawlines (image, pts0, pts1, color):
    for pt0, pt1 in zip(pts0, pts1):
        cv2.line(image,(pt0[0],pt0[1]),(pt1[0],pt1[1]),color,thickness=2);

def calcFlowLib (prev, curr, points):
    #OPTICAL FLOW USING OPENCV IMPLEMENTATION
    currpts = np.reshape(points,(-1,1,2));
    lk_params = dict(winSize=(41,41), maxLevel=0, criteria=(cv2.TERM_CRITERIA_EPS|cv2.TERM_CRITERIA_COUNT,10,0.03));
    nextpts, stat, err = cv2.calcOpticalFlowPyrLK(prev,curr,currpts,None,**lk_params);
    nextpts = np.reshape(nextpts,(-1,2));
    return nextpts;

def calcFlow (im1, im2, points, halfwin=(20,20)):
    #MY OWN IMPLEMENTATION
    pts = np.copy(points)
    npts = points.shape[0]

    i_x = np.zeros(im1.shape)
    i_y = np.zeros(im1.shape)
    i_t = np.zeros(im1.shape)
    i_x[1:-1, 1:-1] = (im1[1:-1, 2:] - im1[1:-1, :-2]) / 2
    i_y[1:-1, 1:-1] = (im1[2:, 1:-1] - im1[:-2, 1:-1]) / 2
    i_t[1:-1, 1:-1] = im2[1:-1, 1:-1] - im1[1:-1, 1:-1]


    for i in xrange(0,npts,1):
        p = np.reshape(pts[i],(2,1))

        ix = i_x[p[1]-halfwin[1]:p[1]+halfwin[1]+1,p[0]-halfwin[0]:p[0]+halfwin[0]+1]
        iy = i_y[p[1]-halfwin[1]:p[1]+halfwin[1]+1,p[0]-halfwin[0]:p[0]+halfwin[0]+1]            
        it = i_t[p[1]-halfwin[1]:p[1]+halfwin[1]+1,p[0]-halfwin[0]:p[0]+halfwin[0]+1]

        ixx = ix*ix
        iyy = iy*iy
        ixy = ix*iy
        ixt = ix*it
        iyt = iy*it

        G = np.array([[np.sum(ixx),np.sum(ixy)],[np.sum(ixy),np.sum(iyy)]],dtype=np.float32)
        B = np.array([[np.sum(ixy)],[np.sum(iyt)]],dtype=np.float32)
        vel = np.linalg.lstsq(G,B)[0]
        pts[i] = pts[i] + np.ravel(vel)        

    return pts


cap = cv2.VideoCapture("OF.mp4")    
prevgray = None
currgray = None
prevpts0 = np.array([[320,180],[100,100]],dtype=np.float32)
prevpts1 = np.array([[320,180],[100,100]],dtype=np.float32)
while(cap.isOpened()):
    ret, frame = cap.read()
    if not ret:
        break
    frame = cv2.resize(frame,(640,360))
    currgray = cv2.cvtColor(frame,cv2.COLOR_BGR2GRAY)

    if(prevgray is not None):
        currpts0 = calcFlow(prevgray,currgray,prevpts0)
        drawlines(frame,prevpts0,currpts0,(0,255,0)) 
        currpts1 = calcFlowLib(prevgray,currgray,prevpts1)
        drawlines(frame,prevpts1,currpts1,(0,0,255))
        prevpts0 = np.copy(currpts0) 
        prevpts1 = np.copy(currpts1)

    prevgray = np.copy(currgray)
    cv2.imshow("Frame",frame)
    if cv2.waitKey(1) & 0xFF == ord('1'):
        break
cap.release()
cv2.destroyAllWindows()

我的实现的错误部分在哪里？

这个问题几乎是“过于宽泛”，在实现过程中可能存在多个问题。我建议您将代码稍微扩展到一个用户可以运行并包含或链接到输入图像的位置。如果你能做到这一点，你就更有可能得到帮助。