CAMShift

While CAMShift adds complexity to Meanshift, the implementation of the the preceding program using CAMShift is surprisingly (or not?) similar to the Meanshift example, with the main difference being that, after the call to CamShift, the rectangle is drawn with a particular rotation that follows the rotation of the object being tracked.

Here's the code reimplemented with CAMShift:

import numpy as np
import cv2

cap = cv2.VideoCapture(0)

# take first frame of the video
ret,frame = cap.read()

# setup initial location of window
r,h,c,w = 300,200,400,300  # simply hardcoded the values
track_window = (c,r,w,h)


roi = frame[r:r+h, c:c+w]
hsv_roi =  cv2.cvtColor(frame, cv2.COLOR_BGR2HSV)
mask = cv2.inRange(hsv_roi, np.array((100., 30.,32.)), np.array((180.,120.,255.)))
roi_hist = cv2.calcHist([hsv_roi],[0],mask,[180],[0,180])
cv2.normalize(roi_hist,roi_hist,0,255,cv2.NORM_MINMAX)
term_crit = ( cv2.TERM_CRITERIA_EPS | cv2.TERM_CRITERIA_COUNT, 10, 1 )

while(1):
    ret ,frame = cap.read...