这是代码
import cv2
import numpy
import time
class CaptureManager(object):
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 = long(0)
self._fpsEstimate = None
@property
def channel(self):
return self._channel
@channel.setter
def channel(self,value):
if self._channel != value:
self._channel = value
self.frame = None
@property
def frame(self):
if self._enteredFrame and self._frame is None:
_, self.frame = self._capture.retrieve()
return self.frame
@property
def isWritingImage(self):
return self._imageFilename is not None
@property
def isWritingVideo(self):
return self._videoFilename is not None
def enterFrame(self):
"""Capture the next frame,if any."""
#but first,check that any previous frame was exited.
assert not self._enteredFrame,\
'previous enterFrame() had no maching exitFrame()'
if self._capture is not None:
self._enteredFrame = self._capture.grab()
def exitFrame(self):
"""Draw to the window. Write to files.Release the frame."""
#Check whether any grabbed frame is retriveable.
#The getter may retrieve and cache the frame.
if self.frame is None:
self._enteredFrame = False
return
#Update the FPS estimate and related variables.
if self._framesElapsed == 0:
self._startTime = time.time()
else:
timeElapsed = time.time() - self.startTime
self.fpsEstimate = self._framesElapsed / timeElapsed
self._framesElapsed += 1
#Draw to the Window,if any.
if self.previewWindowManager is not None:
if self.showldMirrorPreview:
mirroredFrame = numpy.fliplr(self._frame).copy()
self.previewWindowManager.show(mirroredFrame)
else:
self.previewWindowManager.show(self._frame)
#Write to the image file,if any.
if self.isWrintingImage:
cv2.imwrite(self.imageFilename,self._frame)
self._imageFilename = None
#Write to the video file,if any.
self._writeVideoFrame()
#Release the frame.
self._frame = None
self.enteredFrame = False
def writeImage(self,filename):
"""Write the next exited frame to an image file."""
self._imageFilename = filename
def startWritingVideo(self,filename,encoding = cv2.VideoWriter_fourcc('I','4','2','0')):
"""Start writing exited frames to a video file."""
self._videoFilename = filename
self._videoEnchding = None
self._videoWriter = None
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:
#The capture's FPS is unknown so use an entimate.
if self._framesElapsed < 20:
#Wait until more frames frames elapse so that the estimate is more stable.
return
else:
fps = self._fpsEstimate
size = (int(self._capture.get(cv2.CAP_PROP_FRAME_WIDTH)),int(self._capture.get(cv2.CAP_FRAME_HEIGHT)))
self._videoWriter = cv2.VideoWriter(self._videoFilename,self._videoEncoding,fps,size)
self._videoWriter.write(self._frame)
class WindowManager(object):
def init(self,windowName,keypressCallback = None):
self.keypressCallback = keypressCallback
self._windowName = windowName
self._isWindowCreated = False
@property
def isWindowCreated(self):
return self._iswindowCreated
def creatWindow(self):
cv2.namedWindow(self._windowName)
self._isWindowCreated = True
def show(self,frame):
cv2.imshow(self._windowName,frame)
def destroyWindow(self):
cv2.destroyWindow(self._windowName)
self._isWindowCreated = False
def processEvents(self):
keycode = cv2.waitKey(1)
if self.keypressCallback is not None and keycode != -1:
#Discard any non-ASCII info encoded by GTY.
keycode &= 0xFF
self.keypressCallback(keycode)
运行一下报错
Traceback (most recent call last):
File "G:\opencv\usrcold\managers.py", line 5, in
class CaptureManager(object):
File "G:\opencv\usrcold\managers.py", line 76, in CaptureManager
self._framesElapsed += 1
NameError: name 'self' is not defined
为什么~
很明显你的缩进有问题吧？
import cv2
import numpy as np
import time
class CaptureManager(object):
def __init__(self,capture,previewWindowManger = None,shouldMirrorPreview = False):
self.previewWindowManger = previewWindowManger
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 = 0
self._fpsEstimate = None
@property
def channel(self):
return self._channel
@channel.setter
def channel(self,value):
if self._channel != value:
self._channel = value
self._frame = None
@property
def frame(self):
if self._enteredFrame and self._frame is None:
_,self._frame = self._capture.retrieve()
return self._frame
@property
def isWritingImage(self):
return self._imageFilename is not None
@property
def isWritingVideo(self):
return self._videoFilename is not None
def enterFrame (self):
assert not self._enteredFrame,\
'previous enterFrame() had no matching enterFrame()'
if self._capture is not None:
self._enteredFrame = self._capture.grab()
def exitFrame (self):
if self._frame is None:
self._enteredFrame = False
return
if self._framesElapsed == 0:
self.startTime = time.time()
else:
timeElapsed = time.time()-self.startTime
self._fpsEstimate = self._framesElapsed/timeElapsed
self._framesElapsed += 1
if self.previewWindowManger is not None:
if self.shouldMirrorPreview:
mirroredFrame = np.fliplr(self._frame).copy()
self.previewWindowManger.show(mirroredFrame)
else:
self.previewWindowManger.show(self._frame)
if self.isWritingImage:
cv2.imwrite(self._imageFilename,self._frame)
self._imageFilename = None
self._writeVideoFrame()
self._frame = None
self._enteredFrame = False
def writeImage(self,filename):
self._imageFilename = filename
def startWritingVideo(self,filename,encoding = cv2.VideoWriter_fourcc('i','4','2','0')):
self._videoFilename = filename
self._videoEncoding = encoding
def stopWritingVideo(self):
self._videoFilename = None
self._videoEncoding = None
self._videoWriter = None
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._frameElapsed <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)
class WindowManager(object):
def __init__(self,windowName,keypressCallback = None):
self.keypressCallback = keypressCallback
self._windowName = windowName
self._isWindowCreated = False
@property
def isWindowCreated(self):
return self._isWindowCreated
def createWindow(self):
cv2.namedWindow(self._windowName)
self._isWindowCreated = True
def show(self,frame):
cv2.imshow(self._windowName,frame)
def destroyWindow(self):
cv2.destroyWindow(self._windowName)
self._isWindowCreated = False
def processEvents(self):
keycode = cv2.waitKey(1)
if self.keypressCallback is not None and keycode != -1:
keycode &= 0xff
self.keypressCallback(keycode)
我今天也遇到这个问题了，最后这样就好了