学习《OpenCV3计算机视觉，Python语言实现》时读书笔记。
最近对计算机视觉产生了浓厚的兴趣，又刚好在学校的图书馆看到了这本书，那可刚好满足了我的兴趣，今天先敲一个Cameo。
保存图片视频时，直接通过当前日期进行保存。
先创建一个manager.py
import cv2
import numpy
import time
# 视频图像管理类
class CaptureManager(object):
# 类变量前加 _ 代表将变量设置保护变量，只有类对象和子类才能访问
# 类变量前加 __ 代表将变量设置私有变量，只有类对象才能访问
def __init__(self, capture, previewWindowManager = None, shouldMirrorPreview = False):
self.previewWindowManager = previewWindowManager
self.shouldMirrorPreview = shouldMirrorPreview
self._capture = capture
self._channel = 0
self._enteredFrame = False
self._frame = None
self._imageFilename = None
self._videoFilename = None
self._videoEncoding = None
self._videoWriter = None
self._startTime = None
self._framesElapsed = float(0)
self._fpsEstimate = None
# 设置只读属性
@property
def channel(self):
return self._channel
# 设置可写属性
@channel.setter
def channel(self, value):
if self._channel != value:
self._channel = value
self._frame = None
# 设置只读属性
@property
def frame(self):
if self._enteredFrame and self._frame is None:
_, self._frame = self._capture.retrieve()
return self._frame
# 设置只读属性
@property #装饰器的用法具体了解可以参考这位小哥的博客
#https://blog.youkuaiyun.com/u013205877/article/details/77804137
def isWritingImage(self):
# return self._imageFilename is not None 首先判断self._imageFilename是否为None，若是，返回False，否则返回True
# if self._imageFilename:
# return True
# else:
# return False
return self._imageFilename is not None
# 设置只读属性
@property
def isWritingVideo(self):
return self._videoFilename is not None
# 启动摄像头录制功能
def enterFrame(self):
"""Capture the next frame, if any"""
assert not self._enteredFrame, 'previous enterFrame() had no mathcing exitFrame'
if self._capture is not None:
self._enteredFrame = self._capture.grab()
# 程序里最复杂的就是这方法了，担负了视频显示、视频视频录制、截屏保存的功能。
def exitFrame (self):
"""Draw to the window. Write to files. Release the frame"""
if self.frame is None:
self._enteredFrame = False
return
# 计算fps
if self._framesElapsed == 0:
self._startTime = time.time()
else:
timeElapsed = time.time() - self._startTime
self._fpsEstimate = self._framesElapsed / timeElapsed
self._framesElapsed += 1
# 显示图像
if self.previewWindowManager is not None:
if self.shouldMirrorPreview:
# 向左/右方向翻转阵列，翻转图像
mirroredFrame = numpy.fliplr(self._frame).copy()
self.previewWindowManager.show(mirroredFrame)
else:
self.previewWindowManager.show(self._frame)
# 图片文件生成
if self.isWritingImage:
cv2.imwrite(self._imageFilename, self._frame)
self._imageFilename = None
# 录像生成
self._writeVideoFrame()
self._frame = None
self._enteredFrame = False
# 设置图片文件名
def writeImage(self, filename):
"""Wirte the next exited frame to an image file."""
self._imageFilename = filename
# 开始录制
def startWritingVideo(self, filename, encodeing = cv2.VideoWriter_fourcc('I', '4', '2', '0')):
"""Start wirting exited frames to a video file."""
self._videoFilename = filename
self._videoEncoding = encodeing
# 停止录制
def stopWritingVideo(self):
"""Stop writing eited frames to a video file."""
self._videoFilename = None
self._videoEncodding = None
self._videoWriter = None
# 录制视频
def _writeVideoFrame(self):
if not self.isWritingVideo:
return
if self._videoWriter is None:
fps = self._capture.get(cv2.CAP_PROP_FPS)
if fps == 0.0:
if self._framesElapsed < 20:
return
else:
fps = self._fpsEstimate
size = (int(self._capture.get(cv2.CAP_PROP_FRAME_WIDTH)), int(self._capture.get(cv2.CAP_PROP_FRAME_HEIGHT)))
self._videoWriter = cv2.VideoWriter(self._videoFilename, self._videoEncoding, fps, size)
self._videoWriter.write(self._frame)
# 创建界面管理类
class WindowManager(object):
def __init__(self, windowName, keypressCallback = None):
self.keypressCallback = keypressCallback
self._windowName = windowName
self._isWindowCreated = False
# 设置只读属性
@property
def isWindowCreated(self):
return self._isWindowCreated
# 创建窗口
def createWindow(self):
cv2.namedWindow(self._windowName)
self._isWindowCreated = True
# 显示窗口
def show(self, frame):
cv2.imshow(self._windowName, frame)
# 注销窗口
def destroyWindow(self):
cv2.destroyWindow(self._windowName)
self._isWindowCreated = False
# 执行键盘操作的回调函数
def processEvents(self):
keycode = cv2.waitKey(1)
if self.keypressCallback is not None and keycode != -1:
# Discard any non-ASCII info encoded by GTK.
keycode &= 0xFF
self.keypressCallback(keycode)接下来创建cameo.py
import cv2
import datetime
from managers import WindowManager, CaptureManager
class Cameo(object):
def __init__(self):
# 创建一个窗口，并将键盘的回调函数传入
self._windowManager = WindowManager('Video_Date', self.onKeypress)
# 告诉程序数据来自摄像头， 还有镜面效果
self._captureManager = CaptureManager(cv2.VideoCapture(0), self._windowManager, True)
def run(self):
"""Run the main loop."""
self._windowManager.createWindow()
while self._windowManager.isWindowCreated:
# 这里的enterFrame就是告诉程序从摄像头中取数据
self._captureManager.enterFrame()
# 下面的这个frame是原始帧数据，这里没有做任何修改，后面的教程会对这个帧数据进行修改
frame = self._captureManager._frame
# exitFrame看起来是像是退出的意思，其实主要功能都是在这里方法里实现的，截屏、录像都是在这里
self._captureManager.exitFrame()
# 回调函数
self._windowManager.processEvents()
# 定义键盘的回调函数，用于self._windowManager.processEvents()的调用
def onKeypress(self, keycode):
'''
快捷键设置：
当按下“空格”键的时候，会进行抓屏。
当按下‘tab’键的时候，就开始或者停止录像。
当然相应的目录也会生成图片或者视频文件
'''
s = datetime.datetime.now().strftime('%Y-%m-%d')
if keycode == 32: # space
# 截屏保存的文件名字
self._captureManager.writeImage(s + '.png')
elif keycode == 9: # tab
if not self._captureManager.isWritingVideo:
# 告诉程序，录像保存的文件名字
self._captureManager.startWritingVideo(s + '_DateVideo.avi')
else:
self._captureManager.stopWritingVideo()
elif keycode == 27: # escape
self._windowManager.destroyWindow()
if __name__ == "__main__":
Cameo().run()最后完美实现。
代码永不停息...
扫一扫
被折叠的 条评论
为什么被折叠?
到【灌水乐园】发言
