如何在视频中用open cv画虚线？

Question

我试着用这段代码在视频上画一个动画点。

from collections import deque
from imutils.video import VideoStream
import numpy as np
import cv2
import imutils
import time

vs = cv2.VideoCapture('/media/intercept.mp4')    
pts = deque(maxlen=64) #buffer size

# keep looping
while True:
    ret,frame = vs.read()

    if frame is None:
        break
    # resize the frame, blur it, and convert it to the HSV
    # color space
    frame = imutils.resize(frame, width=600)
    blurred = cv2.GaussianBlur(frame, (11, 11), 0)
    hsv = cv2.cvtColor(frame, cv2.COLOR_BGR2HSV)

    for i in range(10,260,20):
        time.sleep(0.5)     #To visualise dots one by one
        cv2.circle(frame,(i, i),10, (0,0,255), -1) #draw circle
        cv2.imshow('frame',frame)     #show output image
        if cv2.waitKey(1) == ord('q'):
            break

    cv2.imshow("Frame", frame)
    key = cv2.waitKey(1) & 0xFF
    # if the 'q' key is pressed, stop the loop
    if key == ord("q"):
        break

cv2.destroyAllWindows()
vs.release()    

但整个动画发生在一帧中，而不是连续的帧。另外，我还想在红色球圈上添加一定的抖动随机性元素，如何实现这两点？

Answer 1

啊，通过调整睡眠定时器，跳过帧，解决了这个问题。

from collections import deque
from imutils.video import VideoStream
import numpy as np
import cv2
import imutils
import time

vs = cv2.VideoCapture('/media/intercept.mp4')
pts = deque(maxlen=64) #buffer size

i=0
ct=0
# keep looping
while True:
    ret,frame = vs.read()
    # resize the frame, blur it, and convert it to the HSV
    # color space
    frame = imutils.resize(frame, width=600)
    blurred = cv2.GaussianBlur(frame, (11, 11), 0)
    hsv = cv2.cvtColor(frame, cv2.COLOR_BGR2HSV)

    i+=2
    ct+=10
    #for i in range(10,260,20):
        #time.sleep(0.5)     #To visualise dots one by one
    if ct%10==0:
        cv2.circle(frame,(i, i),10, (0,0,255), -1) #draw circle
        #cv2.imshow('frame',frame)     #show output image
        if cv2.waitKey(1) == ord('q'):
            break

    cv2.imshow("Frame", frame)
    key = cv2.waitKey(1) & 0xFF
    # if the 'q' key is pressed, stop the loop
    if key == ord("q"):
        break

cv2.destroyAllWindows()
vs.release()