OpenCV 相机相关函数

一、变换参数矩阵的求解

计算三个二维点对之间的仿射变换矩阵：getAffineTransform()
计算多个二维点对之间的最优放射变换矩阵（误差最小准则）：estimateRigidTransform();或者findHomography();
计算四个二维点对之间的透射变换：getPerspectiveTransform();
计算多个三维点对之间的仿射变换：estimateAffine3D();
计算多个点对之间的基矩阵：findFundamentalMat();

二、进行矩阵变换

对输入图像进行仿射变换：warpAffine();
对输入图像进行透射变换：perspectiveTransform();和warpPerspective();
对输入二维点对进行仿射变换：transform(); 该函数还可用于色彩变换
对输入三维点对进行透射变换：perspectiveTransform();

三、来自相机标定工具箱的函数

估算物体位置和姿态：cvPOSIT();
根据对应三维点恢复位置姿态，实现物体位置的二维坐标三维坐标之间的变换：solvePnP()和solvePnPRansac()
合并两个旋转平移变换：composeRT()
把点从欧式空间转换到齐次坐标：convertPointsToHomogeneous()
把点从其次空间转换到欧式空间：convertPointsFromHomogeneous()

以上两个函数合并为：convertPointsHomogeneous()

将矩阵分解：decomposeProjectionMatrix()
检测棋盘格内角点的位置：findChessboardCorners()
绘制检测出的棋盘格内的角点位置：drawChessboardCorners()
得到圆圈光栅中圆斑的中心：findCirclesGrid()
计算两幅图像关联点的基础矩阵：findFundamentalMat()
计算其它图像对应的外极线：computeCorrespondEpilines()

cv2.absdiff()
cv2.accumulate()
cv2.accumulateProduct()
cv2.accumulateSquare()
cv2.accumulateWeighted()
cv2.adaptiveThreshold() # 图像自适应局部二值化
cv2.add() # 两个图像相加
cv2.addText() # 添加文字
cv2.addWeighted() # 调整图像亮度与对比度
cv2.applyColorMap()
cv2.approxPolyDP() # 多边形逼近轮廓
cv2.arcLength() # 轮廓周长,弧长
cv2.arrowedLine() # 带箭头的线
cv2.ACCESS_FAST #todo

cv2.batchDistance()
cv2.bilateralFilter() # 高斯双边滤波。保留图像的边缘，边缘保留滤波，用于美颜，滤镜
cv2.bitwise_and() # 两个图像的逻辑与运算
cv2.bitwise_not() # 一个图像的像素取反
cv2.bitwise_or() # 两个图像的逻辑或运算
cv2.bitwise_xor() # 异或
cv2.blur() # 图像均值模糊
cv2.borderInterpolate()
cv2.boundingRect() # 轮廓的外接矩形
cv2.boxFilter()
cv2.boxPoints()
cv2.buildOpticalFlowPyramid() # 构建光流金字塔
cv2.BackgroundSubtractor # 类，视频背景检测
cv2.BackgroundSubtractor.apply()
cv2.BackgroundSubtractor.clear
cv2.BackgroundSubtractor.empty()
cv2.BackgroundSubtractor.getBackgroundImage()
cv2.BackgroundSubtractor.getDefaultName()
cv2.BackgroundSubtractor.mro()
cv2.BackgroundSubtractor.read()
cv2.BackgroundSubtractor.save()
cv2.BackgroundSubtractor.write()
cv2.BackgroundSubtractorKNN #类
cv2.BackgroundSubtractorKNN.apply()
cv2.BackgroundSubtractorKNN.clear()
cv2.BackgroundSubtractorKNN.empty()
cv2.BackgroundSubtractorKNN.getBackgroundImage()
cv2.BackgroundSubtractorKNN.getDefaultName()
cv2.BackgroundSubtractorKNN.getDetectShadows()
cv2.BackgroundSubtractorKNN.getDist2Threshold()
cv2.BackgroundSubtractorKNN.getHistory()
cv2.BackgroundSubtractorKNN.getkNNSamples()
cv2.BackgroundSubtractorKNN.getShadowThreshold()
cv2.BackgroundSubtractorKNN.getShadowValue()
cv2.BackgroundSubtractorKNN.mro()
cv2.BackgroundSubtractorKNN.read()
cv2.BackgroundSubtractorKNN.save()
cv2.BackgroundSubtractorKNN.setDetectShadows()
cv2.BackgroundSubtractorKNN.setDist2Threshold()
cv2.BackgroundSubtractorKNN.setHistory()
cv2.BackgroundSubtractorKNN.setkNNSamples()
cv2.BackgroundSubtractorKNN.setNSamples()
cv2.BackgroundSubtractorKNN.setShadowThreshold()
cv2.BackgroundSubtractorKNN.setShadowValue()
cv2.BackgroundSubtractorKNN.write()
cv2.BackgroundSubtractorMOG2
cv2.BaseCascadeClassifier
cv2.BFMatcher # 类。Brute-Force图像特征特征匹配
cv2.BFMatcher_create()
cv2.BFMatcher.match()
cv2.BOWImgDescriptorExtractor
cv2.BOWKMeansTrainer
cv2.BOWTrainer
cv2.BRISK
cv2.BRISK_create()

cv2.calcBackProject() # 在HSV色彩空间中，直方图反向投影。可用于检测目标
cv2.calcCovarMatrix()
cv2.calcHist() # 计算图像的直方图
cv2.calcOpticalFlowFarneback()
cv2.calcOpticalFlowPyrLK() # Lucas-Kanade光流算法
cv2.calibrateCamera() # 相机校正
cv2.calibrateCameraExtended()
cv2.calibrateCameraRO()
cv2.calibrateCameraROExtended()
cv2.calibrateHandEye()
cv2.calibrationMatrixValues() # 从相机矩阵中计算相机特征
cv2.cartToPolar()
cv2.checkChessboard()
cv2.checkHardwareSupport()
cv2.checkRange()
cv2.circle() # 画圆
cv2.clipLine()
cv2.CLAHE() # CLAHE直方图均衡化
cv2.colorChange()
cv2.compare()
cv2.compareHist() # 比较两个图像的直方图。可用于两个图像之间的相似性
cv2.completeSymm()
cv2.composeRT() # 旋转和平移变换的组合
cv2.computeCorrespondEpilines()
cv2.computeECC()
cv2.connectedComponents() # 图像的连通区域
cv2.connectedComponentsWithAlgorithm()
cv2.connectedComponentsWithStats()
cv2.connectedComponentsWithStatsWithAlgorithm()
cv2.contourArea() # 轮廓面积
cv2.convertFp16()
cv2.convertMaps()
cv2.convertPointsFromHomogeneous()
cv2.convertPointsToHomogeneous()
cv2.convertScaleAbs() # 绝对值变换
cv2.convexHull() # 绘制点集的凸壳
cv2.convexityDefects() # 凸面缺陷
cv2.copyMakeBorder()
cv2.copyTo()
cv2.cornerEigenValsAndVecs()
cv2.cornerHarris() #Harris角点
cv2.cornerSubPix()
cv2.correctMatches() # 修正对应点的坐标
cv2.countNonZero() # 非零值个数
cv2.createAlignMTB()
cv2.createBackgroundSubtractorKNN()
cv2.createBackgroundSubtractorMOG2() # 高斯混合模型，用于视频的背景检测
cv2.createButton()
cv2.createCalibrateDebevec()
cv2.createCalibrateRobertson()
cv2.createCLAHE() #灰度图局部自适应的直方图均衡化。
cv2.createGeneralizedHoughBallard()
cv2.createGeneralizedHoughGuil()
cv2.createHanningWindow()
cv2.createLineSegmentDetector()
cv2.createMergeDebevec()
cv2.createMergeMertens()
cv2.createMergeRobertson()
cv2.createTonemap()
cv2.createTonemapDrago()
cv2.createTonemapMantiuk()
cv2.createTonemapReinhard()
cv2.createTrackbar()
cv2.cubeRoot()
cv2.cuda()
cv2.cuda_BufferPool()
cv2.cuda_DeviceInfo()
cv2.cuda_Event()
cv2.cuda_GpuMat()
cv2.cuda_GpuMat_Allocator()
cv2.cuda_HostMem()
cv2.cuda_Stream()
cv2.cuda_TargetArchs()
cv2.cvtColor() #转换图像颜色空间。肤色识别一般用HSV颜色空间
cv2.cvtColorTwoPlane()
cv2.CALIB_CB_ACCURACY() #todo
cv2.CalibrateCRF #类
cv2.CalibrateDebevec #类
cv2.CalibrateRobertson #类
cv2.CamShift()
cv2.Canny() # Canny边缘检测
cv2.CascadeClassifier # 类，级联分类器。例如人脸检测
cv2.CascadeClassifier_convert()

cv2.data()
cv2.dct()
cv2.decolor()
cv2.decomposeEssentialMat()
cv2.decomposeHomographyMat()
cv2.decomposeProjectionMatrix() #把投影矩阵分解成旋转矩阵和相机矩阵
cv2.demosaicing()
cv2.denoise_TVL1()
cv2.destroyAllWindows()
cv2.destroyWindow()
cv2.detail()
cv2.detail_AffineBasedEstimator() #todo
cv2.dft()
cv2.dilate() # 二值图像的膨胀。膨胀后图像线条变粗
cv2.displayOverlay()
cv2.displayStatusBar()
cv2.distanceTransform() # 距离变换
cv2.distanceTransformWithLabels()
cv2.divide() #两个图像相除
cv2.dnn.blobFromImage #图像或一帧视频的缩放变换
cv2.dnn.blobFromImages
cv2.dnn.DNN_BACKEND_CUDA
cv2.dnn.DNN_BACKEND_DEFAULT
cv2.dnn.DNN_BACKEND_HALIDE
cv2.dnn.DNN_BACKEND_INFERENCE_ENGINE
cv2.dnn.DNN_BACKEND_OPENCV
cv2.dnn.DNN_BACKEND_VKCOM
cv2.dnn.DNN_TARGET_CPU
cv2.dnn.DNN_TARGET_CUDA
cv2.dnn.DNN_TARGET_CUDA_FP16
cv2.dnn.DNN_TARGET_FPGA
cv2.dnn.DNN_TARGET_MYRIAD
cv2.dnn.DNN_TARGET_OPENCL
cv2.dnn.DNN_TARGET_OPENCL_FP16
cv2.dnn.DNN_TARGET_VULKAN
cv2.dnn.imagesFromBlob
cv2.dnn.Net_readFromModelOptimizer
cv2.dnn.NMSBoxes
cv2.dnn.NMSBoxesRotated
cv2.dnn.readNet
cv2.dnn.readNetFromCaffe
cv2.dnn.readNetFromDarknet
cv2.dnn.readNetFromModelOptimizer
cv2.dnn.readNetFromONNX
cv2.dnn.readNetFromTensorflow
cv2.dnn.readNetFromTorch
cv2.dnn.readTensorFromONNX
cv2.dnn.readTorchBlob
cv2.dnn.shrinkCaffeModel
cv2.dnn.writeTextGraph
cv2.drawChessboardCorners() # 绘制图像中的黑白交界处
cv2.drawContours() # 绘制轮廓
cv2.drawFrameAxes()
cv2.drawKeypoints()
cv2.drawMarker()
cv2.drawMatches() # 画出特征点匹配的结果
cv2.drawMatchesKnn() # 画出特征点匹配的结果
cv2.DCT_INVERSE()
cv2.DenseOpticalFlow # 密集光流类
cv2.DescriptorMatcher # 描述子匹配类
cv2.DescriptorMatcher_create()
cv2.DISOpticalFlow # 类
cv2.DISOpticalFlow_create()
cv2.DMatch # 类

cv2.edgePreservingFilter()
cv2.eigen()
cv2.eigenNonSymmetric()
cv2.ellipse() # 画椭圆
cv2.ellipse2Poly()
cv2.equalizeHist() # 用于灰度图的全局直方图均衡化。可用于增强图像的对比度，亮的地方更亮，黑的地方更黑。
cv2.erode() # 二值图像的腐蚀。腐蚀后图像线条变细
cv2.error()
cv2.estimateAffine2D()
cv2.estimateAffine3D()
cv2.estimateAffinePartial2D()
cv2.exp() #计算指数
cv2.extractChannel()
cv2.EMD()#todo

cv2.fastAtan2()
cv2.fastNlMeansDenoising()
cv2.fastNlMeansDenoisingColored()
cv2.fastNlMeansDenoisingColoredMulti()
cv2.fastNlMeansDenoisingMulti()
cv2.fillConvexPoly()
cv2.fillPoly()
cv2.filter2D() # 图像2D卷积滤波
cv2.filterHomographyDecompByVisibleRefpoints()
cv2.filterSpeckles() # 过滤掉小的噪音块
cv2.find4QuadCornerSubpix()
cv2.findChessboardCorners() # 获取图像中的黑白交界处
cv2.findChessboardCornersSB() # 获取图像中的黑白交界处
cv2.findCirclesGrid() # 寻找圆心点
cv2.findContours() # 寻找二值化图中的轮廓
cv2.findEssentialMat()
cv2.findFundamentalMat() # 计算两个图像中对应点之间的基础矩阵
cv2.findHomography() # 计算两个平面之间的透视变换
cv2.findNonZero()
cv2.findTransformECC()
cv2.fisheye # 模块，鱼眼相机模型
cv2.fisheye.calibrate
cv2.fisheye.distortPoints
cv2.fisheye.estimateNewCameraMatrixForUndistortRectify
cv2.fisheye.initUndistortRectifyMap（） # 在相机标定完后，得到x轴与y轴映射
cv2.fisheye.projectPoints
cv2.fisheye.stereoCalibrate
cv2.fisheye.stereoRectify
cv2.fisheye.undistortImage
cv2.fisheye.undistortPoints
cv2.fitEllipse() # 拟合椭圆
cv2.fitEllipseAMS()
cv2.fitEllipseDirect()
cv2.fitLine()
cv2.flann()
cv2.flann_Index()
cv2.flip() # 翻转图片或视频的一帧
cv2.floodFill() # 图像泛洪填充，填充方式 cv2.FLOODFILL_FIXED_RANGE，cv2.FLOODFILL_MASK_ONLY
cv2.FarnebackOpticalFlow() #todo
cv2.FlannBasedMatcher # 类。#FLANN图像特征特征匹配
cv2.FlannBasedMatcher_create()
cv2.FlannBasedMatcher.knnMatch()

cv2.gemm()
cv2.getAffineTransform()
cv2.getBuildInformation()
cv2.getCPUTickCount()
cv2.getDefaultNewCameraMatrix()
cv2.getDerivKernels()
cv2.getFontScaleFromHeight()
cv2.getGaborKernel()
cv2.getGaussianKernel()
cv2.getHardwareFeatureName()
cv2.getNumberOfCPUs() # CPU数量
cv2.getNumThreads() # 线程数量
cv2.getOptimalDFTSize()
cv2.getOptimalNewCameraMatrix() # 在相机标定完后，得到新的矩阵
cv2.getPerspectiveTransform()
cv2.getRectSubPix()
cv2.getRotationMatrix2D()
cv2.getStructuringElement() # 获取结构元素。用于构建形态学操作的核
cv2.getTextSize() # 获取文本大小
cv2.getThreadNum()
cv2.getTickCount() # 获取CPU时间
cv2.getTickFrequency()
cv2.getTrackbarPos()
cv2.getValidDisparityROI()
cv2.getVersionMajor()
cv2.getVersionMinor()
cv2.getVersionRevision()
cv2.getVersionString()
cv2.getWindowImageRect()
cv2.getWindowProperty()
cv2.goodFeaturesToTrack() # 检测视频中的角点
cv2.grabCut() # GrabCut提取前景
cv2.groupRectangles()
cv2.GaussianBlur() # Gauss模糊
cv2.GeneralizedHough # 类
cv2.GeneralizedHoughBallard # 类
cv2.GeneralizedHoughGuil # 类
cv2.GFTTDetector # 类
cv2.GFTTDetector_create()

cv2.haarcascades()
cv2.hconcat()
cv2.HOGDescriptor_getDaimlerPeopleDetector()
cv2.HOGDescriptor_getDefaultPeopleDetector()
cv2.HoughCircles() # Hough圆检测
cv2.HoughLines() # Hough直线检测，极坐标
cv2.HoughLinesP() # Hough检测直线的起点、终点
cv2.HoughLinesPointSet()
cv2.HuMoments() # Hu矩
cv2.HISTCMP_BHATTACHARYYA() # todo

cv2.isContourConvex # 轮廓是否是凸的
cv2.idct
cv2.idft
cv2.illuminationChange
cv2.imdecode
cv2.imencode
cv2.importlib
cv2.imread # 读图片或视频一帧
cv2.imreadmulti
cv2.imshow # 显示图片
cv2.imwrite # 把图片保存到外部文件
cv2.inpaint
cv2.inRange
cv2.INTERSECT_PARTIAL #todo

cv2.kmeans()
cv2.KalmanFilter() #todo

cv2.line() # 画直线
cv2.linearPolar()
cv2.log()
cv2.logPolar()
cv2.Laplacian() # Laplacian边缘提取算子
cv2.LDR_SIZE()
cv2.LineSegmentDetector # 类
cv2.LUT
#todo

cv2.magnitude()
cv2.matchShapes() # 形状匹配
cv2.matchTemplate() # 图片模板匹配
cv2.matMulDeriv()
cv2.max()
cv2.mean() # 一个图像的均值
cv2.meanShift()
cv2.meanStdDev() # 一个图像的均值、标准差
cv2.medianBlur() # 图像中值模糊
cv2.merge() # 合并颜色通道
cv2.min()
cv2.minAreaRect() # 图像的最小外接矩形
cv2.minEnclosingCircle() # 图像最小外接圆
cv2.minEnclosingTriangle()
cv2.minMaxLoc() # 获取图片中最小、最大值的坐标。一般用在图片模板匹配中。
cv2.mixChannels()
cv2.ml #ml包
cv2.ml_ANN_MLP() # 类
cv2.ml_Boost()
cv2.ml_DTrees()
cv2.ml_EM()
cv2.ml_KNearest()
cv2.ml_LogisticRegression()
cv2.ml_NormalBayesClassifier()
cv2.ml_ParamGrid()
cv2.ml_RTrees()
cv2.ml_StatModel()
cv2.ml_SVM()
cv2.ml_SVMSGD()
cv2.ml_TrainData()
cv2.moments() # 图像矩
cv2.morphologyEx() # 二值图像的形态学操作。例如开操作、闭操作、顶帽、黑帽、内梯度、外梯度。
# 开操作可以：1）提取水平或竖直线。2）移除细的干扰直线或干扰块
cv2.moveWindow()
cv2.mulSpectrums()
cv2.multiply() # 两个图像相乘
cv2.mulTransposed()
cv2.Mahalanobis() # todo

cv2.namedWindow()
cv2.norm() # 向量或句矩阵的范数
cv2.normalize() # 正则化
cv2.NORM_HAMMING() # todo

cv2.os()
cv2.ocl()
cv2.ocl_Device()
cv2.OPTFLOW_FARNEBACK_GAUSSIAN
cv2.OPTFLOW_LK_GET_MIN_EIGENVALS
cv2.OPTFLOW_USE_INITIAL_FLOW
cv2.ORB # 类。ORB特征，比SIFT、SUFRF快
cv2.ORB_create()
cv2.ORB_FAST_SCORE
cv2.ORB_HARRIS_SCORE

cv2.patchNaNs()
cv2.pencilSketch()
cv2.perspectiveTransform()
cv2.phase()
cv2.phaseCorrelate()
cv2.pointPolygonTest() # 点到轮廓距离
cv2.polarToCart()
cv2.polylines() # 画多边形
cv2.pow()
cv2.preCornerDetect()
cv2.projectPoints()
cv2.putText()
cv2.pyrDown() # 图像金字塔下采样
cv2.pyrMeanShiftFiltering() # 均值迁移滤波。一种高斯双边滤波，保留图像的边缘，边缘保留滤波，油画效果，用于美颜，滤镜
cv2.pyrUp() # 图像金字塔上采样
cv2.PARAM_ALGORITHM() # todo
cv2.QRCodeDetector() # todo

cv2.randn()
cv2.randShuffle()
cv2.randu()
cv2.readOpticalFlow()
cv2.recoverPose()
cv2.rectangle() # 画矩形
cv2.rectify3Collinear()
cv2.redirectError()
cv2.reduce()
cv2.remap() # 在相机标定完后,将原图映射到新图
cv2.repeat()
cv2.reprojectImageTo3D()
cv2.resize()
cv2.resizeWindow()
cv2.rotate()
cv2.rotatedRectangleIntersection()
cv2.RANSAC() #todo
cv2.Rodrigues # 把旋转矩阵变成旋转向量，或把旋转向量变成旋转矩阵
cv2.RQDecomp3x3 # 计算3*3矩阵的RQ分解

cv2.samples()
cv2.sampsonDistance()
cv2.scaleAdd()
cv2.seamlessClone()
cv2.selectROI()
cv2.selectROIs()
cv2.sepFilter2D()
cv2.setIdentity()
cv2.setMouseCallback()
cv2.setNumThreads()
cv2.setRNGSeed()
cv2.setTrackbarMax()
cv2.setTrackbarMin()
cv2.setTrackbarPos()
cv2.setUseOpenVX()
cv2.setUseOptimized()
cv2.setWindowProperty()
cv2.setWindowTitle()
cv2.solve()
cv2.solveCubic()
cv2.solveLP()
cv2.solveP3P()
cv2.solvePnP() #从3与2D的对应关系中，发现物体的姿态
cv2.solvePnPGeneric()
cv2.solvePnPRansac() #用RANSAC算法从3与2D的对应关系中，发现物体的姿态
cv2.solvePnPRefineLM()
cv2.solvePnPRefineVVS()
cv2.solvePoly()
cv2.sort()
cv2.sortIdx()
cv2.spatialGradient()
cv2.split() #分隔颜色通道成BGR
cv2.sqrBoxFilter()
cv2.sqrt() #开方
cv2.startWindowThread()
cv2.stereoCalibrate()
cv2.stereoCalibrateExtended()
cv2.stereoRectify()
cv2.stereoRectifyUncalibrated()
cv2.stylization()
cv2.subtract() #两个图像相减
cv2.sumElems()
cv2.Scharr() #Scharr边缘提取算子，是Sobel算子的增强算法
cv2.StereoBM #类，用块对应算法计算双目立体匹配
cv2.StereoSGBM #类，用半全局块对应算法计算双目立体匹配
cv2.SimpleBlobDetector #类
cv2.SimpleBlobDetector_create()
cv2.SimpleBlobDetector_Params #类
cv2.Sobel() #Sobel边缘提取算子
cv2.SparseOpticalFlow #类
cv2.SparsePyrLKOpticalFlow #类
cv2.SparsePyrLKOpticalFlow_create
cv2.StereoBM_create()
cv2.StereoMatcher #类
cv2.Stitcher #类
cv2.Stitcher_create()
cv2.Subdiv2D #类
cv2.SVBackSubst()
cv2.SVDecomp() #SVD分解
#todo

cv2.textureFlattening()
cv2.threshold() #图像整体二值化
cv2.trace()
cv2.transform() #变换
cv2.transpose() #转置
cv2.triangulatePoints() #用三角化重建点
cv2.TERM_CRITERIA_COUNT() #todo
cv2.TickMeter #类
cv2.Tonemap #类
cv2.TonemapDrago #类
cv2.TonemapMantiuk #类
cv2.TonemapReinhard #类

cv2.undistort() #在相机标定完后，直接得到去畸变的图像
cv2.undistortPoints()
cv2.undistortPointsIter()
cv2.useOpenVX()
cv2.useOptimized()
cv2.utils()
#todo
cv2.UMat() #类
cv2.UMAT_AUTO_STEP
cv2.UMat_AUTO_STEP
cv2.UMat_context
cv2.UMAT_CONTINUOUS_FLAG
cv2.UMat_CONTINUOUS_FLAG
cv2.UMAT_DATA_ASYNC_CLEANUP
cv2.UMAT_DATA_COPY_ON_MAP
cv2.UMAT_DATA_DEVICE_COPY_OBSOLETE
cv2.UMAT_DATA_DEVICE_MEM_MAPPED
cv2.UMAT_DATA_HOST_COPY_OBSOLETE
cv2.UMAT_DATA_TEMP_COPIED_UMAT
cv2.UMAT_DATA_TEMP_UMAT
cv2.UMAT_DATA_USER_ALLOCATED
cv2.UMAT_DEPTH_MASK #todo
cv2.UMAT_TYPE_MASK
cv2.UMatData_ASYNC_CLEANUP
cv2.USAGE_ALLOCATE_HOST_MEMORY
#todo

cv2.validateDisparity()
cv2.vconcat()
cv2.videoio_registry()
cv2.VariationalRefinement()
cv2.VariationalRefinement_create()
cv2.VideoCapture() #打开摄像头或视频文件的类
cv2.VideoCapture.get
cv2.VideoCapture.getBackendName
cv2.VideoCapture.getExceptionMode
cv2.VideoCapture.grab
cv2.VideoCapture.isOpened
cv2.VideoCapture.mro
cv2.VideoCapture.open
cv2.VideoCapture.read() #读取视频中的一帧图片
cv2.VideoCapture.release
cv2.VideoCapture.retrieve
cv2.VideoCapture.set
cv2.VideoCapture.setExceptionMode

cv2.VideoWriter() #写视频类
cv2.VideoWriter_fourcc()
cv2.VIDEOWRITER_PROP_FRAMEBYTES
cv2.VIDEOWRITER_PROP_NSTRIPES
cv2.VIDEOWRITER_PROP_QUALITY

cv2.waitKey()
cv2.waitKeyEx()
cv2.warpAffine() #仿射变换
cv2.warpPerspective() #投影变换
cv2.warpPolar()
cv2.watershed() # 分水岭算法
cv2.writeOpticalFlow()
#todo
cv2.WARP_FILL_OUTLIERS()
cv2.WARP_INVERSE_MAP
cv2.WARP_POLAR_LINEAR
cv2.WARP_POLAR_LOG
cv2.WarperCreator()
cv2.WINDOW_AUTOSIZE
cv2.WINDOW_FREERATIO
cv2.WINDOW_FULLSCREEN
cv2.WINDOW_GUI_EXPANDED
cv2.WINDOW_GUI_NORMAL
cv2.WINDOW_KEEPRATIO
cv2.WINDOW_FULLSCREEN
cv2.WND_PROP_OPENGL
cv2.WND_PROP_TOPMOST
cv2.WND_PROP_VISIBLE