OpenCV, librairie C/C++ opensource de traitement d’image.

Introduction

• Cette librairie permet de réaliser du traitement d’image avancé et dispose de plusieurs milliers de fonctions dédiées. Les utilisations typiques possibles :
  • traitements d’image de base (flou, seuillage, filtre Guaussien, Sobel)
  • algorithmes d’analyse d’image (reconnaissance de lignes, de cercle)
  • détection de contour
  • reconnaissance et suivi d’objet
  • …
• Je présente cette librairie ici, car elle est utilisable sous Processing, soit à l’aide de la librairie OpenCV Processing, soit via javacv, une librairie qui implémente les fonctions openCV en java et est donc utilisable sous Processing.

Liens essentiels

• Présentation wikipédia : http://fr.wikipedia.org/wiki/OpenCV
• Le site officiel : http://opencv.willowgarage.com/wiki/ (willowgarage est une société de robotique californienne qui maintient la librairie depuis 2010)
• La documentation de la 2.3.1 : http://opencv.itseez.com/ (Itseez est une startup qui supporte OpenCV)
• La librairie javacv, implémentation Java de la librairie openCV : http://code.google.com/p/javacv/ Cette librairie fait le « pont » entre la librairie openCV écrite en C/C++ et le langage Java. Cette librairie permet d’accéder relativement simplement aux fonctions d’openCV directement dans Processing notamment.

Installation

• Compilation/Installation d’OpenCV 2.3.1 sous Ubuntu 10.04
• Installation de javacv dans Processing

Structure de la librairie

• core. Le coeur de la librairie
• imgproc. Traitement d’image
• highgui. Interface Utilisateur Graphique et gestion des E/S (fichiers)
• video. Analyse vidéo
• calib3d. Calibration de caméra et reconnaissance 3D
• features2d. Outils 2D
• objdetect. Détection d’objet
• ml. Algorithmes d’apprentissage
• flann. Recherche dans des espaces à dimensions multiples
• gpu. Vision par ordinateur accélérée

Dans le cadre d’une approche basique, et pour un objectif de robotique amateur, l’utilisation des fonctions des modules « core » et « imgproc » constitue une bonne base.

Vue d’ensemble des fonctions de la librairie

Fonctions du module core

    * Basic Structures
          o DataType
          o Point_
          o Point3_
          o Size_
          o Rect_
          o RotatedRect
          o TermCriteria
          o Matx
          o Vec
          o Scalar_
          o Range
          o Ptr
          o Mat
          o Matrix Expressions
          o Mat::Mat
          o Mat::~Mat
          o Mat::operator =
          o Mat::operator MatExpr
          o Mat::row
          o Mat::col
          o Mat::rowRange
          o Mat::colRange
          o Mat::diag
          o Mat::clone
          o Mat::copyTo
          o Mat::convertTo
          o Mat::assignTo
          o Mat::setTo
          o Mat::reshape
          o Mat::t
          o Mat::inv
          o Mat::mul
          o Mat::cross
          o Mat::dot
          o Mat::zeros
          o Mat::ones
          o Mat::eye
          o Mat::create
          o Mat::addref
          o Mat::release
          o Mat::resize
          o Mat::reserve
          o Mat::push_back
          o Mat::pop_back
          o Mat::locateROI
          o Mat::adjustROI
          o Mat::operator()
          o Mat::operator CvMat
          o Mat::operator IplImage
          o Mat::total
          o Mat::isContinuous
          o Mat::elemSize
          o Mat::elemSize1
          o Mat::type
          o Mat::depth
          o Mat::channels
          o Mat::step1
          o Mat::size
          o Mat::empty
          o Mat::ptr
          o Mat::at
          o Mat::begin
          o Mat::end
          o Mat_
          o NAryMatIterator
          o SparseMat
          o SparseMat_
    * Basic C Structures and Operations
          o CvPoint
          o CvPoint2D32f
          o CvPoint3D32f
          o CvPoint2D64f
          o CvPoint3D64f
          o CvSize
          o CvSize2D32f
          o CvRect
          o CvScalar
          o CvTermCriteria
          o CvMat
          o CvMatND
          o CvSparseMat
          o IplImage
          o CvArr
          o ClearND
          o CloneImage
          o CloneMat
          o CloneMatND
          o CloneSparseMat
          o ConvertScale
          o Copy
          o CreateData
          o CreateImage
          o CreateImageHeader
          o CreateMat
          o CreateMatHeader
          o CreateMatND
          o CreateMatNDHeader
          o CreateSparseMat
          o CrossProduct
          o DotProduct
          o Get?D
          o GetCol(s)
          o GetDiag
          o GetDims
          o GetDimSize
          o GetElemType
          o GetImage
          o GetImageCOI
          o GetImageROI
          o GetMat
          o GetNextSparseNode
          o GetRawData
          o GetReal?D
          o GetRow(s)
          o GetSize
          o GetSubRect
          o DecRefData
          o IncRefData
          o InitImageHeader
          o InitMatHeader
          o InitMatNDHeader
          o InitSparseMatIterator
          o Mat
          o Ptr?D
          o ReleaseData
          o ReleaseImage
          o ReleaseImageHeader
          o ReleaseMat
          o ReleaseMatND
          o ReleaseSparseMat
          o ResetImageROI
          o Reshape
          o ReshapeMatND
          o Set
          o Set?D
          o SetData
          o SetImageCOI
          o SetImageROI
          o SetReal?D
          o SetZero
          o mGet
          o mSet
          o SetIPLAllocators
          o RNG
          o RandArr
          o RandInt
          o RandReal
          o fromarray
    * Dynamic Structures
          o CvMemStorage
          o CvMemBlock
          o CvMemStoragePos
          o CvSeq
          o CvSlice
          o CvSet
          o CvGraph
          o CvGraphScanner
          o CvTreeNodeIterator
          o ClearGraph
          o ClearMemStorage
          o ClearSeq
          o ClearSet
          o CloneGraph
          o CloneSeq
          o CreateChildMemStorage
          o CreateGraph
          o CreateGraphScanner
          o CreateMemStorage
          o CreateSeq
          o CreateSet
          o CvtSeqToArray
          o EndWriteSeq
          o FindGraphEdge
          o FindGraphEdgeByPtr
          o FlushSeqWriter
          o GetGraphVtx
          o GetSeqElem
          o GetSeqReaderPos
          o GetSetElem
          o GraphAddEdge
          o GraphAddEdgeByPtr
          o GraphAddVtx
          o GraphEdgeIdx
          o GraphRemoveEdge
          o GraphRemoveEdgeByPtr
          o GraphRemoveVtx
          o GraphRemoveVtxByPtr
          o GraphVtxDegree
          o GraphVtxDegreeByPtr
          o GraphVtxIdx
          o InitTreeNodeIterator
          o InsertNodeIntoTree
          o MakeSeqHeaderForArray
          o MemStorageAlloc
          o MemStorageAllocString
          o NextGraphItem
          o NextTreeNode
          o PrevTreeNode
          o ReleaseGraphScanner
          o ReleaseMemStorage
          o RestoreMemStoragePos
          o SaveMemStoragePos
          o SeqElemIdx
          o SeqInsert
          o SeqInsertSlice
          o SeqInvert
          o SeqPop
          o SeqPopFront
          o SeqPopMulti
          o SeqPush
          o SeqPushFront
          o SeqPushMulti
          o SeqRemove
          o SeqRemoveSlice
          o SeqSearch
          o SeqSlice
          o SeqSort
          o SetAdd
          o SetNew
          o SetRemove
          o SetRemoveByPtr
          o SetSeqBlockSize
          o SetSeqReaderPos
          o StartAppendToSeq
          o StartReadSeq
          o StartWriteSeq
          o TreeToNodeSeq
    * Operations on Arrays
          o abs
          o absdiff
          o add
          o addWeighted
          o bitwise_and
          o bitwise_not
          o bitwise_or
          o bitwise_xor
          o calcCovarMatrix
          o cartToPolar
          o checkRange
          o compare
          o completeSymm
          o convertScaleAbs
          o countNonZero
          o cvarrToMat
          o dct
          o dft
          o divide
          o determinant
          o eigen
          o exp
          o extractImageCOI
          o flip
          o gemm
          o getConvertElem
          o getOptimalDFTSize
          o idct
          o idft
          o inRange
          o invert
          o log
          o LUT
          o magnitude
          o Mahalanobis
          o max
          o mean
          o meanStdDev
          o merge
          o min
          o minMaxLoc
          o mixChannels
          o mulSpectrums
          o multiply
          o mulTransposed
          o norm
          o normalize
          o PCA
          o PCA::PCA
          o PCA::operator ()
          o PCA::project
          o PCA::backProject
          o perspectiveTransform
          o phase
          o polarToCart
          o pow
          o RNG
          o RNG::RNG
          o RNG::next
          o RNG::operator T
          o RNG::operator ()
          o RNG::uniform
          o RNG::gaussian
          o RNG::fill
          o randu
          o randn
          o randShuffle
          o reduce
          o repeat
          o scaleAdd
          o setIdentity
          o solve
          o solveCubic
          o solvePoly
          o sort
          o sortIdx
          o split
          o sqrt
          o subtract
          o SVD
          o SVD::SVD
          o SVD::operator ()
          o SVD::compute
          o SVD::solveZ
          o SVD::backSubst
          o sum
          o theRNG
          o trace
          o transform
          o transpose
    * Drawing Functions
          o circle
          o clipLine
          o ellipse
          o ellipse2Poly
          o fillConvexPoly
          o fillPoly
          o getTextSize
          o InitFont
          o line
          o LineIterator
          o rectangle
          o polylines
          o putText
    * XML/YAML Persistence
          o XML/YAML file storages. Writing to a file storage.
          o Reading data from a file storage.
          o FileStorage
          o FileNode
          o FileNodeIterator
    * XML/YAML Persistence (C API)
          o CvFileStorage
          o CvFileNode
          o CvAttrList
          o CvTypeInfo
          o Clone
          o EndWriteStruct
          o FindType
          o FirstType
          o GetFileNode
          o GetFileNodeByName
          o GetFileNodeName
          o GetHashedKey
          o GetRootFileNode
          o Load
          o OpenFileStorage
          o Read
          o ReadByName
          o ReadInt
          o ReadIntByName
          o ReadRawData
          o ReadRawDataSlice
          o ReadReal
          o ReadRealByName
          o ReadString
          o ReadStringByName
          o RegisterType
          o Release
          o ReleaseFileStorage
          o Save
          o StartNextStream
          o StartReadRawData
          o StartWriteStruct
          o TypeOf
          o UnregisterType
          o Write
          o WriteComment
          o WriteFileNode
          o WriteInt
          o WriteRawData
          o WriteReal
          o WriteString
    * Clustering
          o kmeans
          o partition
    * Utility and System Functions and Macros
          o alignPtr
          o alignSize
          o allocate
          o deallocate
          o fastAtan2
          o cubeRoot
          o Ceil
          o Floor
          o Round
          o IsInf
          o IsNaN
          o CV_Assert
          o error
          o Exception
          o fastMalloc
          o fastFree
          o format
          o checkHardwareSupport
          o getNumThreads
          o getThreadNum
          o getTickCount
          o getTickFrequency
          o getCPUTickCount
          o saturate_cast
          o setNumThreads
          o setUseOptimized
          o useOptimized

Fonctions du module improc

    * Image Filtering
          o BaseColumnFilter
          o BaseFilter
          o BaseRowFilter
          o FilterEngine
          o bilateralFilter
          o blur
          o borderInterpolate
          o boxFilter
          o buildPyramid
          o copyMakeBorder
          o createBoxFilter
          o createDerivFilter
          o createGaussianFilter
          o createLinearFilter
          o createMorphologyFilter
          o createSeparableLinearFilter
          o dilate
          o erode
          o filter2D
          o GaussianBlur
          o getDerivKernels
          o getGaussianKernel
          o getKernelType
          o getStructuringElement
          o medianBlur
          o morphologyEx
          o Laplacian
          o pyrDown
          o pyrUp
          o pyrMeanShiftFiltering
          o sepFilter2D
          o Smooth
          o Sobel
          o Scharr
    * Geometric Image Transformations
          o convertMaps
          o getAffineTransform
          o getPerspectiveTransform
          o getRectSubPix
          o getRotationMatrix2D
          o invertAffineTransform
          o LogPolar
          o remap
          o resize
          o warpAffine
          o warpPerspective
          o initUndistortRectifyMap
          o getDefaultNewCameraMatrix
          o undistort
          o undistortPoints
    * Miscellaneous Image Transformations
          o adaptiveThreshold
          o cvtColor
          o distanceTransform
          o floodFill
          o inpaint
          o integral
          o threshold
          o watershed
          o grabCut
    * Histograms
          o calcHist
          o calcBackProject
          o compareHist
          o EMD
          o equalizeHist
          o Extra Histogram Functions (C API)
          o CalcBackProjectPatch
          o CalcProbDensity
          o ClearHist
          o CopyHist
          o CreateHist
          o GetHistValue*D
          o GetMinMaxHistValue
          o MakeHistHeaderForArray
          o NormalizeHist
          o QueryHistValue*D
          o ReleaseHist
          o SetHistBinRanges
          o ThreshHist
          o CalcPGH
    * Structural Analysis and Shape Descriptors
          o moments
          o HuMoments
          o findContours
          o drawContours
          o approxPolyDP
          o ApproxChains
          o arcLength
          o boundingRect
          o contourArea
          o convexHull
          o ConvexityDefects
          o fitEllipse
          o fitLine
          o isContourConvex
          o minAreaRect
          o minEnclosingCircle
          o matchShapes
          o pointPolygonTest
    * Planar Subdivisions (C API)
          o CvSubdiv2D
          o CvQuadEdge2D
          o CvSubdiv2DPoint
          o CalcSubdivVoronoi2D
          o ClearSubdivVoronoi2D
          o CreateSubdivDelaunay2D
          o FindNearestPoint2D
          o Subdiv2DEdgeDst
          o Subdiv2DGetEdge
          o Subdiv2DNextEdge
          o Subdiv2DLocate
          o Subdiv2DRotateEdge
          o SubdivDelaunay2DInsert
    * Motion Analysis and Object Tracking
          o accumulate
          o accumulateSquare
          o accumulateProduct
          o accumulateWeighted
    * Feature Detection
          o Canny
          o cornerEigenValsAndVecs
          o cornerHarris
          o cornerMinEigenVal
          o cornerSubPix
          o goodFeaturesToTrack
          o HoughCircles
          o HoughLines
          o HoughLinesP
          o preCornerDetect
    * Object Detection
          o matchTemplate

Fonctions du module

    * User Interface
          o createTrackbar
          o getTrackbarPos
          o imshow
          o namedWindow
          o destroyWindow
          o destroyAllWindows
          o MoveWindow
          o ResizeWindow
          o SetMouseCallback
          o setTrackbarPos
          o waitKey
    * Reading and Writing Images and Video
          o imdecode
          o imencode
          o imread
          o imwrite
          o VideoCapture
          o VideoCapture::VideoCapture
          o VideoCapture::open
          o VideoCapture::isOpened
          o VideoCapture::release
          o VideoCapture::grab
          o VideoCapture::retrieve
          o VideoCapture::read
          o VideoCapture::get
          o VideoCapture::set
          o VideoWriter
          o VideoWriter::VideoWriter
          o ReleaseVideoWriter
          o VideoWriter::open
          o VideoWriter::isOpened
          o VideoWriter::write
    * Qt New Functions
          o setWindowProperty
          o getWindowProperty
          o fontQt
          o addText
          o displayOverlay
          o displayStatusBar
          o createOpenGLCallback
          o saveWindowParameters
          o loadWindowParameters
          o createButton

Fonctions du module