所以我遵循这个教程,但它似乎没有做任何事情。只是没有。它等待几秒钟并关闭程序。这段代码有什么问题?
import cv2
vidcap = cv2.VideoCapture('Compton.mp4')
success,image = vidcap.read()
count = 0
success = True
while success:
success,image = vidcap.read()
cv2.imwrite("frame%d.jpg" % count, image) # save frame as JPEG file
if cv2.waitKey(10) == 27: # exit if Escape is hit
break
count += 1
此外,在评论中它说这限制帧到1000?为什么?
编辑:
我试着先做success = True,但没有帮助。它只创建了一个0字节的图像。
我可能在这里迟到了,但你可以使用这个PIP包从视频中快速生成图像。你也可以使用特定的fps来获取图像。
pip安装videoToImages
然后在终端中输入以下命令
视频到图像 --视频文件夹 [路径到视频文件夹]
示例:videoToimages——videoofolder "c:/videos"
对于特定的输出FPS,将——FPS 10设置为任何所需的值。-fps 1表示视频中每秒钟一个图像。
完整的命令:
videoToimages—视频文件夹“c:/videos”
videoToimages——videoofolder "c:/videos"——fps 10——img_size (512, 512)
之前的答案已经失去了第一帧。把图片存储在文件夹里会很好。
# create a folder to store extracted images
import os
folder = 'test'
os.mkdir(folder)
# use opencv to do the job
import cv2
print(cv2.__version__) # my version is 3.1.0
vidcap = cv2.VideoCapture('test_video.mp4')
count = 0
while True:
success,image = vidcap.read()
if not success:
break
cv2.imwrite(os.path.join(folder,"frame{:d}.jpg".format(count)), image) # save frame as JPEG file
count += 1
print("{} images are extacted in {}.".format(count,folder))
顺便说一下,你可以通过VLC检查帧率。进入“windows ->媒体信息->编解码器详细信息”
在稍微不同的情况下扩展这个问题(@user2700065的回答),如果有人不想提取每一帧,但想每一秒提取一帧。所以1分钟的视频会有60帧(图像)。
import sys
import argparse
import cv2
print(cv2.__version__)
def extractImages(pathIn, pathOut):
count = 0
vidcap = cv2.VideoCapture(pathIn)
success,image = vidcap.read()
success = True
while success:
vidcap.set(cv2.CAP_PROP_POS_MSEC,(count*1000)) # added this line
success,image = vidcap.read()
print ('Read a new frame: ', success)
cv2.imwrite( pathOut + "\\frame%d.jpg" % count, image) # save frame as JPEG file
count = count + 1
if __name__=="__main__":
a = argparse.ArgumentParser()
a.add_argument("--pathIn", help="path to video")
a.add_argument("--pathOut", help="path to images")
args = a.parse_args()
print(args)
extractImages(args.pathIn, args.pathOut)
在对如何将帧转换为视频进行了大量研究后,我创建了这个函数,希望这能有所帮助。我们需要opencv来实现:
import cv2
import numpy as np
import os
def frames_to_video(inputpath,outputpath,fps):
image_array = []
files = [f for f in os.listdir(inputpath) if isfile(join(inputpath, f))]
files.sort(key = lambda x: int(x[5:-4]))
for i in range(len(files)):
img = cv2.imread(inputpath + files[i])
size = (img.shape[1],img.shape[0])
img = cv2.resize(img,size)
image_array.append(img)
fourcc = cv2.VideoWriter_fourcc('D', 'I', 'V', 'X')
out = cv2.VideoWriter(outputpath,fourcc, fps, size)
for i in range(len(image_array)):
out.write(image_array[i])
out.release()
inputpath = 'folder path'
outpath = 'video file path/video.mp4'
fps = 29
frames_to_video(inputpath,outpath,fps)
修改fps(帧/秒)的值,输入文件夹路径和输出文件夹路径根据您自己的本地位置
下面的脚本将提取帧每半秒的所有视频在文件夹。(适用于python 3.7)
import cv2
import os
listing = os.listdir(r'D:/Images/AllVideos')
count=1
for vid in listing:
vid = r"D:/Images/AllVideos/"+vid
vidcap = cv2.VideoCapture(vid)
def getFrame(sec):
vidcap.set(cv2.CAP_PROP_POS_MSEC,sec*1000)
hasFrames,image = vidcap.read()
if hasFrames:
cv2.imwrite("D:/Images/Frames/image"+str(count)+".jpg", image) # Save frame as JPG file
return hasFrames
sec = 0
frameRate = 0.5 # Change this number to 1 for each 1 second
success = getFrame(sec)
while success:
count = count + 1
sec = sec + frameRate
sec = round(sec, 2)
success = getFrame(sec)