循环在Python中写入需要很多时间。

huangapple
go评论92阅读模式
英文:

loops written in Python take a lot of time

问题

我正在使用Python中的OpenCV制作这个蓝色滤镜，它能够工作，但视频输出有延迟。

  1. import numpy as np
  2. import cv2
  4. cap = cv2.VideoCapture(0)  
  6. while True:
  7.     ret, frame = cap.read()  
  8.     for i in range(frame.shape[0]):
  9.         for j in range(frame.shape[1]):
  10.             frame[i][j] = [255,frame[i][j][1],frame[i][j][2]]
  12.     cv2.imshow('frame',frame)
  14.     if cv2.waitKey(1) == ord('q'):
  15.         break
  17. cap.release()  
  18. cv2.destroyAllWindows()
英文:

I was making this blue colored filter using openCV in python and it works but the video output is lagging.

  1. import numpy as np
  2. import cv2
  4. cap = cv2.VideoCapture(0)  
  6. while True:
  7.     ret, frame = cap.read()  
  8.     for i in range(frame.shape[0]):
  9.         for j in range(frame.shape[1]):
  10.             frame[i][j] = [255,frame[i][j][1],frame[i][j][2]]
  12.     cv2.imshow('frame',frame)
  14.     if cv2.waitKey(1) == ord('q'):
  15.         break
  17. cap.release()  
  18. cv2.destroyAllWindows()

答案1

得分: 1

你可以利用NumPy中的向量化操作来避免显式循环：

  1. import numpy as np
  2. import cv2
  4. cap = cv2.VideoCapture(0)
  6. while True:
  7.     ret, frame = cap.read()
  8.     
  9.     frame[:, :, 0] = 255  # 将蓝色通道设为255（全蓝）
  10.     
  11.     cv2.imshow('frame', frame)
  13.     if cv2.waitKey(1) == ord('q'):
  14.         break
  16. cap.release()
  17. cv2.destroyAllWindows()
英文:

You can utilize vectorized operations in NumPy to avoid the explicit loops:

  1. import numpy as np
  2. import cv2
  4. cap = cv2.VideoCapture(0)
  6. while True:
  7.     ret, frame = cap.read()
  8.     
  9.     frame[:, :, 0] = 255  # Set blue channel to 255 (full blue)
  10.     
  11.     cv2.imshow('frame', frame)
  13.     if cv2.waitKey(1) == ord('q'):
  14.         break
  16. cap.release()
  17. cv2.destroyAllWindows()

huangapple
  • 本文由 发表于 2023年7月17日 21:45:07
  • 转载请务必保留本文链接：https://go.coder-hub.com/76705080.html
  • numpy
  • python
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