OpenCV的(开源计算机视觉)是一种计算机视觉库, 其中包含用于对图像或视频执行操作的各种功能。
OpenCV's application areas include :1) Facial recognition system
2) motion tracking
3) Artificial neural network
4) Deep neural network
5) video streamingetc.
在Python中, 可以使用一个名为CV2。 Python不随cv2一起提供, 因此用户需要单独安装它。
对于Windows:pip install opencv-pythonOpenCv库可用于对视频执行多项操作。让我们尝试使用CV2。将视频作为输入, 然后通过将视频逐帧拆分为反向并将其存储在列表中, 以反向模式播放。获取帧列表后, 我们对帧进行迭代。要以反向模式播放视频, 我们只需要在帧列表中迭代反向即可。使用列表的反转方法可以反转列表中帧的顺序。
对于Linux:sudo apt-get install python-opencv
下面是实现:
# Python program to play a video
# in reverse mode using opencv # import cv2 library
import cv2# videoCapture method of cv2 return video object# Pass absolute address of video file
cap = cv2.VideoCapture( "video_file_location" )# read method of video object will return
# a tuple with 1st element denotes whether
# the frame was read successfully or not, # 2nd element is the actual frame.# Grab the current frame.
check , vid = cap.read()# counter variable for
# counting frames
counter = 0# Initialize the value
# of check variable
check = Trueframe_list = []# If reached the end of the video
# then we got False value of check.# keep looping untill we
# got False value of check.
while (check = = True ):# imwrite method of cv2 saves the
# image to the specified format.
cv2.imwrite( "frame%d.jpg" % counter , vid)
check , vid = cap.read()# Add each frame in the list by
# using append method of the List
frame_list.append(vid)# increment the counter by 1
counter + = 1# last value in the frame_list is None
# because when video reaches to the end
# then false value store in check variable
# and None value is store in vide variable.# removing the last value from the
# frame_list by using pop method of List
frame_list.pop()# looping in the List of frames.
for frame in frame_list:# show the frame.
cv2.imshow( "Frame" , frame)# waitkey method to stoping the frame
# for some time. q key is presses, # stop the loop
if cv2.waitKey( 25 ) and 0xFF = = ord ( "q" ):
break# release method of video
# object clean the input video
cap.release()# close any open windows
cv2.destroyAllWindows()# reverse the order of the element
# present in the list by using
# reverse method of the List.
frame_list.reverse()for frame in frame_list:
cv2.imshow( "Frame" , frame)
if cv2.waitKey( 25 ) and 0xFF = = ord ( "q" ):
breakcap.release()
cv2.destroyAllWindows()
输出:
文章图片
【Python使用OpenCV反向播放视频()】首先, 你的面试准备可通过以下方式增强你的数据结构概念:Python DS课程。
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