OpenCV  4.1.0
Open Source Computer Vision
Public Member Functions | Static Public Member Functions | Protected Member Functions | List of all members
cv::Algorithm Class Reference
Basic structures

This is a base class for all more or less complex algorithms in OpenCV. More...

#include <opencv2/core.hpp>

Inheritance diagram for cv::Algorithm:
cv::AlignExposures cv::BackgroundSubtractor cv::BaseCascadeClassifier cv::bgsegm::SyntheticSequenceGenerator cv::bioinspired::Retina cv::bioinspired::RetinaFastToneMapping cv::bioinspired::TransientAreasSegmentationModule cv::CalibrateCRF cv::ccalib::CustomPattern cv::CLAHE cv::cuda::CannyEdgeDetector cv::cuda::CascadeClassifier cv::cuda::Convolution cv::cuda::CornernessCriteria cv::cuda::CornersDetector cv::cuda::DenseOpticalFlow cv::cuda::DescriptorMatcher cv::cuda::DFT cv::cuda::DisparityBilateralFilter cv::cuda::Filter cv::cuda::HOG cv::cuda::HoughCirclesDetector cv::cuda::HoughLinesDetector cv::cuda::HoughSegmentDetector cv::cuda::ImagePyramid cv::cuda::LookUpTable cv::cuda::SparseOpticalFlow cv::cuda::TemplateMatching cv::DenseOpticalFlow cv::DescriptorMatcher cv::dnn::Layer cv::face::BIF cv::face::Facemark cv::face::FaceRecognizer cv::face::MACE cv::Feature2D cv::freetype::FreeType2 cv::GeneralizedHough cv::hfs::HfsSegment cv::HistogramCostExtractor cv::img_hash::ImgHashBase cv::line_descriptor::BinaryDescriptor cv::line_descriptor::BinaryDescriptorMatcher cv::line_descriptor::LSDDetector cv::LineSegmentDetector cv::LMSolver cv::MergeExposures cv::MinProblemSolver cv::ml::StatModel cv::ml::SVM::Kernel cv::MultiTracker cv::optflow::GPCForest< T > cv::optflow::GPCTree cv::phase_unwrapping::PhaseUnwrapping cv::plot::Plot2d cv::quality::QualityBase cv::rgbd::DepthCleaner cv::rgbd::Odometry cv::rgbd::RgbdNormals cv::rgbd::RgbdPlane cv::saliency::Saliency cv::ShapeDistanceExtractor cv::ShapeTransformer cv::SparseOpticalFlow cv::stereo::StereoMatcher cv::StereoMatcher cv::structured_light::StructuredLightPattern cv::superres::DenseOpticalFlowExt cv::superres::SuperResolution cv::text::ERFilter cv::Tonemap cv::Tracker cv::xfeatures2d::PCTSignatures cv::xfeatures2d::PCTSignaturesSQFD cv::ximgproc::AdaptiveManifoldFilter cv::ximgproc::ContourFitting cv::ximgproc::DisparityFilter cv::ximgproc::DTFilter cv::ximgproc::EdgeBoxes cv::ximgproc::FastBilateralSolverFilter cv::ximgproc::FastGlobalSmootherFilter cv::ximgproc::FastLineDetector cv::ximgproc::GuidedFilter cv::ximgproc::RFFeatureGetter cv::ximgproc::RidgeDetectionFilter cv::ximgproc::segmentation::GraphSegmentation cv::ximgproc::segmentation::SelectiveSearchSegmentation cv::ximgproc::segmentation::SelectiveSearchSegmentationStrategy cv::ximgproc::SparseMatchInterpolator cv::ximgproc::StructuredEdgeDetection cv::ximgproc::SuperpixelLSC cv::ximgproc::SuperpixelSEEDS cv::ximgproc::SuperpixelSLIC cv::xphoto::WhiteBalancer

Public Member Functions

 Algorithm ()
 
virtual ~Algorithm ()
 
virtual void clear ()
 Clears the algorithm state.
 
virtual bool empty () const
 Returns true if the Algorithm is empty (e.g. in the very beginning or after unsuccessful read.
 
virtual String getDefaultName () const
 
virtual void read (const FileNode &fn)
 Reads algorithm parameters from a file storage.
 
virtual void save (const String &filename) const
 
virtual void write (FileStorage &fs) const
 Stores algorithm parameters in a file storage.
 
void write (const Ptr< FileStorage > &fs, const String &name=String()) const
 simplified API for language bindingsThis is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
 

Static Public Member Functions

template<typename _Tp >
static Ptr< _Tp > load (const String &filename, const String &objname=String())
 Loads algorithm from the file.
 
template<typename _Tp >
static Ptr< _Tp > loadFromString (const String &strModel, const String &objname=String())
 Loads algorithm from a String.
 
template<typename _Tp >
static Ptr< _Tp > read (const FileNode &fn)
 Reads algorithm from the file node.
 

Protected Member Functions

void writeFormat (FileStorage &fs) const
 

Detailed Description

This is a base class for all more or less complex algorithms in OpenCV.

especially for classes of algorithms, for which there can be multiple implementations. The examples are stereo correspondence (for which there are algorithms like block matching, semi-global block matching, graph-cut etc.), background subtraction (which can be done using mixture-of-gaussians models, codebook-based algorithm etc.), optical flow (block matching, Lucas-Kanade, Horn-Schunck etc.).

Here is example of SimpleBlobDetector use in your application via Algorithm interface:

Ptr<Feature2D> sbd = SimpleBlobDetector::create();
FileStorage fs_read("SimpleBlobDetector_params.xml", FileStorage::READ);
if (fs_read.isOpened()) // if we have file with parameters, read them
{
sbd->read(fs_read.root());
fs_read.release();
}
else // else modify the parameters and store them; user can later edit the file to use different parameters
{
fs_read.release();
FileStorage fs_write("SimpleBlobDetector_params.xml", FileStorage::WRITE);
sbd->write(fs_write);
fs_write.release();
}
Mat result, image = imread("../data/detect_blob.png", IMREAD_COLOR);
vector<KeyPoint> keypoints;
sbd->detect(image, keypoints, Mat());
drawKeypoints(image, keypoints, result);
for (vector<KeyPoint>::iterator k = keypoints.begin(); k != keypoints.end(); ++k)
circle(result, k->pt, (int)k->size, Scalar(0, 0, 255), 2);
imshow("result", result);
waitKey(0);

Constructor & Destructor Documentation

cv::Algorithm::Algorithm ( )
virtual cv::Algorithm::~Algorithm ( )
virtual

Member Function Documentation

virtual void cv::Algorithm::clear ( )
inlinevirtual

Clears the algorithm state.

Reimplemented in cv::FlannBasedMatcher, cv::line_descriptor::BinaryDescriptorMatcher, cv::DescriptorMatcher, cv::cuda::DescriptorMatcher, cv::quality::QualityPSNR, cv::quality::QualityBase, cv::quality::QualityGMSD, cv::quality::QualitySSIM, and cv::quality::QualityMSE.

virtual bool cv::Algorithm::empty ( ) const
inlinevirtual

Returns true if the Algorithm is empty (e.g. in the very beginning or after unsuccessful read.

Reimplemented in cv::DescriptorMatcher, cv::face::FaceRecognizer, cv::ml::StatModel, cv::Feature2D, cv::BaseCascadeClassifier, cv::cuda::DescriptorMatcher, cv::quality::QualityPSNR, cv::quality::QualityBase, cv::face::BasicFaceRecognizer, cv::quality::QualityGMSD, cv::quality::QualitySSIM, and cv::quality::QualityMSE.

virtual String cv::Algorithm::getDefaultName ( ) const
virtual 
Returns the algorithm string identifier.

This string is used as top level xml/yml node tag when the object is saved to a file or string.

Reimplemented in cv::AKAZE, cv::KAZE, cv::SimpleBlobDetector, cv::GFTTDetector, cv::AgastFeatureDetector, cv::FastFeatureDetector, cv::MSER, cv::ORB, cv::BRISK, and cv::Feature2D.

template<typename _Tp >
static Ptr<_Tp> cv::Algorithm::load ( const String &  filename,
const String &  objname = String() 
)
inlinestatic

Loads algorithm from the file.

Parameters
filenameName of the file to read.
objnameThe optional name of the node to read (if empty, the first top-level node will be used)

This is static template method of Algorithm. It's usage is following (in the case of SVM):

Ptr<SVM> svm = Algorithm::load<SVM>("my_svm_model.xml");

In order to make this method work, the derived class must overwrite Algorithm::read(const FileNode& fn).

template<typename _Tp >
static Ptr<_Tp> cv::Algorithm::loadFromString ( const String &  strModel,
const String &  objname = String() 
)
inlinestatic

Loads algorithm from a String.

Parameters
strModelThe string variable containing the model you want to load.
objnameThe optional name of the node to read (if empty, the first top-level node will be used)

This is static template method of Algorithm. It's usage is following (in the case of SVM):

Ptr<SVM> svm = Algorithm::loadFromString<SVM>(myStringModel);
virtual void cv::Algorithm::read ( const FileNode &  fn)
inlinevirtual

Reads algorithm parameters from a file storage.

Reimplemented in cv::FlannBasedMatcher, cv::DescriptorMatcher, cv::Tracker, cv::face::FaceRecognizer, cv::optflow::GPCForest< T >, cv::line_descriptor::BinaryDescriptor, cv::Feature2D, cv::optflow::GPCTree, cv::saliency::StaticSaliencySpectralResidual, and cv::face::BasicFaceRecognizer.

template<typename _Tp >
static Ptr<_Tp> cv::Algorithm::read ( const FileNode &  fn)
inlinestatic

Reads algorithm from the file node.

This is static template method of Algorithm. It's usage is following (in the case of SVM):

cv::FileStorage fsRead("example.xml", FileStorage::READ);
Ptr<SVM> svm = Algorithm::read<SVM>(fsRead.root());

In order to make this method work, the derived class must overwrite Algorithm::read(const FileNode& fn) and also have static create() method without parameters (or with all the optional parameters)

virtual void cv::Algorithm::save ( const String &  filename) const
virtual 
Saves the algorithm to a file.

In order to make this method work, the derived class must implement Algorithm::write(FileStorage& fs).

virtual void cv::Algorithm::write ( FileStorage &  fs) const
inlinevirtual

Stores algorithm parameters in a file storage.

Reimplemented in cv::FlannBasedMatcher, cv::DescriptorMatcher, cv::Tracker, cv::face::FaceRecognizer, cv::optflow::GPCForest< T >, cv::bioinspired::Retina, cv::line_descriptor::BinaryDescriptor, cv::Feature2D, cv::optflow::GPCTree, cv::bioinspired::TransientAreasSegmentationModule, cv::saliency::StaticSaliencySpectralResidual, and cv::face::BasicFaceRecognizer.

void cv::Algorithm::write ( const Ptr< FileStorage > &  fs,
const String &  name = String() 
) const

simplified API for language bindingsThis is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

void cv::Algorithm::writeFormat ( FileStorage &  fs) const
protected
The documentation for this class was generated from the following file:
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