opencv&Python——多种边缘检测
原教程bug挺多，此处感谢https://blog.csdn.net/qq_34877350/article/details/78583787
话不多说，上代码
comeo.py
# 使用managers.CaptureManager提取视频流
import numpy
import cv2
import time
import filters
from managers import WindowManager,CaptureManager
class Cameo(object):
def __init__(self):
self._windowManager = WindowManager('Cameo', self.onKeypress)
self._captureManager = CaptureManager(cv2.VideoCapture(0), self._windowManager, True)
self._curveFilter = filters.BGRPortraCurveFilter() # 后添加
def run(self):
self._windowManager.createWindow()
while self._windowManager.isWindowCreated:
self._captureManager.enterFrame()
frame = self._captureManager.frame
filters.strokeEdges(frame,frame) # 边缘检测
self._curveFilter.apply(frame,frame)
self._captureManager.exitFrame()
self._windowManager.processEvents()
def onKeypress(self, keycode):
if keycode == 32: # space
self._captureManager.writeImage('cameo/screenshot.png')
elif keycode == 9: # tab
if not self._captureManager.isWritingVideo:
self._captureManager.startWritingVideo('cameo/screenshot.avi')
else:
self._captureManager.stopWritingVideo()
elif keycode == 27: # escape
self._windowManager.destoryWindow()
if __name__ == '__main__':
Cameo().run()
filters.py
# ——创建时间：2019.2.21——
# 添加一些滤波函数的类
import cv2
import numpy
import utils
# 边缘检测
def strokeEdges(src, dst, blurKsize=7, edgeKsize=5):
# 先进行模糊化处理
if blurKsize >= 3:
blurredSrc = cv2.medianBlur(src, blurKsize) # 进行模糊化处理
garySrc = cv2.cvtColor(blurredSrc, cv2.COLOR_BGR2GRAY) # 将色彩空间转换成灰度色彩空间
# blurKsize在3以下时相当于关闭了模糊效果
else:
garySrc = cv2.cvtColor(src, cv2.COLOR_BAYER_BG2BGR)
cv2.Laplacian(garySrc, cv2.CV_8U, garySrc, ksize=edgeKsize) # 进行边缘检测
normalizedInverseAlpha = (1.0 / 255 * (255 - garySrc)) # 将像素值归一化
channels = cv2.split(src)
for channel in channels:
channel[:] = channel * normalizedInverseAlpha # 乘以原图像能将边缘变黑
cv2.merge(channels, dst)
# 一般卷积滤波器
class VConvolutionFilter(object):
def __init__(self, kernel):
self._kernel = kernel
def apply(self, src, dst):
cv2.filter2D(src, -1, self._kernel, dst)
# 锐化卷积滤波器
class SharpenFilter(VConvolutionFilter):
def __init__(self):
kernel = numpy.array([[-1, -1, -1],
[-1, 9, -1],
[-1, -1, -1]]) # 权重加起来等于1不会改变颜色
VConvolutionFilter.__init__(self, kernel)
# 临近平均滤波器
class BlurFilter(VConvolutionFilter):
def __init__(self):
kernel= numpy.array([[0.04,0.04,0.04,0.04,0.04],
[0.04,0.04,0.04,0.04,0.04],
[0.04,0.04,0.04,0.04,0.04],
[0.04,0.04,0.04,0.04,0.04],
[0.04,0.04,0.04,0.04,0.04],])
VConvolutionFilter.__init__(self,kernel)
# 脊状或浮雕效果滤波器
class EmbossFilter(VConvolutionFilter):
def __init__(self):
kernel = numpy.array([[-2,-1,0],
[-1,1,1],
[0,1,2]])
VConvolutionFilter.__init__(self,kernel)
class BGRFuncFilter(object):
def __init__(self, vFunc = None, bFunc = None, gFunc = None, rFunc = None,dtype = numpy.uint8) :
length = numpy.iinfo(dtype).max + 1
self._bLookupArray = utils.createLookupArray(utils.createCompositeFunc(bFunc, vFunc), length)
self._gLookupArray = utils.createLookupArray(utils.createCompositeFunc(gFunc, vFunc), length)
self._rLookupArray = utils.createLookupArray(utils.createCompositeFunc(rFunc, vFunc), length)
def apply(self, src, dst) :
# """Apply the filter with a BGR source/destination."""
b, g, r = cv2.split(src)
utils.applyLookupArray(self._bLookupArray, b, b)
utils.applyLookupArray(self._gLookupArray, g, g)
utils.applyLookupArray(self._rLookupArray, r, r)
cv2.merge([ b, g, r ], dst)
class BGRCurveFilter(BGRFuncFilter):
def __init__(self, vPoints = None, bPoints = None,gPoints = None, rPoints = None, dtype = numpy.uint8):
BGRFuncFilter.__init__(self, utils.createCurveFunc(vPoints), utils.createCurveFunc(bPoints), utils.createCurveFunc(gPoints), utils.createCurveFunc(rPoints), dtype)
class BGRPortraCurveFilter(BGRCurveFilter):
def __init__(self, dtype = numpy.uint8):
BGRCurveFilter.__init__(self,
vPoints = [ (0, 0), (23, 20), (157, 173), (255, 255) ],
bPoints = [ (0, 0), (41, 46), (231, 228), (255, 255) ],
gPoints = [ (0, 0), (52, 47), (189, 196), (255, 255) ],
rPoints = [ (0, 0), (69, 69), (213, 218), (255, 255) ],
dtype = dtype)
managers.py
import cv2
import time
import numpy
# 增加要导入的包、构造函数和属性值
class CaptureManager(object):
def __init__(self, capture, previewWindowManager=None, shouldMirrorPreview=False):
self.previewWindowManager = previewWindowManager
self.shouldMirrorPreview = shouldMirrorPreview # 设置为True时，帧在窗口中国水平翻转，但不记录在文件中
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 = int(0)
self._fpsEstimate = None
@property # 装饰器，方便访问
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 exitFram()'
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.previewWindowManager is not None:
if self.shouldMirrorPreview:
mirroredFrame = numpy.fliplr(self._frame).copy()
self.previewWindowManager.show(mirroredFrame)
else:
self.previewWindowManager.show(self._frame)
if self.isWritingImage:
cv2.imwrite(self._imageFilename, self._frame)
self._imageFilename = None
self._writerVideoFrame()
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 _writerVideoFrame(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)
# 使用managers.WindowManager抽象窗口和键盘
class WindowManager(object):
# 实现支持键盘事件
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 destoryWindow(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)
utils.py
# ——创建时间：2019.2.21——
# 存放一些通用的数学函数
import cv2,numpy,scipy.interpolate
def createCurveFunc(points):
# """Return a function derived from control points."""
if points is None:
return None
num_points = len(points)
if num_points < 2:
return None
xs, ys = zip(*points)
if num_points < 4:
kind = 'linear'
# 'quadratic' is not implemented.
else:
kind = 'cubic'
return scipy.interpolate.interp1d(xs, ys, kind,bounds_error = False)
def createLookupArray(func, length = 256):
# """Return a lookup for whole-number inputs to a function. The lookup values are clamped to [0, length - 1]."""
if func is None:
return None
lookup_array = numpy.empty(length)
i = 0
while i < length:
func_i = func(i)
lookup_array[i] = min(max(0, func_i), length - 1)
i += 1
return lookup_array
def applyLookupArray(lookup_array, src, dst):
# """Map a source to a destination using a lookup."""
if lookup_array is None:
return
dst[:] = lookup_array[src]
def createCompositeFunc(func0, func1):
# """Return a composite of two functions."""
if func0 is None:
return func1
if func1 is None:
return func0
return lambda x: func0(func1(x))
def createFlatView(array):
# """Return a 1D view of an array of any dimensionality."""
flat_view = array.view()
flat_view.shape = array.size
return flat_view
程序完美运行，这是原书的一个比较大的bug！
可以任意在filter.py中选择想要的滤波器