Core functionality

Topics
	Basic structures
	Operations on arrays
	Asynchronous API
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	Utility and system functions and macros
	OpenGL interoperability
	Intel IPP Asynchronous C/C++ Converters
	Optimization Algorithms
	DirectX interoperability
	Eigen support
	OpenCL support
	Intel VA-API/OpenCL (CL-VA) interoperability
	Hardware Acceleration Layer
	Parallel Processing

Detailed Description

Namespaces
namespace	cv::traits

Classes
class	cv::Affine3< T >
	Affine transform. More...
class	cv::BufferPoolController
class	cv::DualQuat< _Tp >
class	cv::Quat< _Tp >
class	cv::QuatEnum

Typedefs
typedef Affine3< double >	cv::Affine3d
typedef Affine3< float >	cv::Affine3f
using	cv::DualQuatd = DualQuat<double>
using	cv::DualQuatf = DualQuat<float>
using	cv::Quatd = Quat<double>
using	cv::Quatf = Quat<float>

Enumerations
enum	cv::CovarFlags {   cv::COVAR_SCRAMBLED = 0 ,   cv::COVAR_NORMAL = 1 ,   cv::COVAR_USE_AVG = 2 ,   cv::COVAR_SCALE = 4 ,   cv::COVAR_ROWS = 8 ,   cv::COVAR_COLS = 16 }
	Covariation flags. More...
enum	cv::QuatAssumeType {   cv::QUAT_ASSUME_NOT_UNIT ,   cv::QUAT_ASSUME_UNIT }
	Unit quaternion flag. More...

Functions
template<typename T>
Quat< T >	cv::acos (const Quat< T > &q)
template<typename T>
Quat< T >	cv::acosh (const Quat< T > &q)
template<typename T>
Quat< T >	cv::asin (const Quat< T > &q)
template<typename T>
Quat< T >	cv::asinh (const Quat< T > &q)
template<typename T>
Quat< T >	cv::atan (const Quat< T > &q)
template<typename T>
Quat< T >	cv::atanh (const Quat< T > &q)
template<typename T>
Quat< T >	cv::cos (const Quat< T > &q)
template<typename T>
Quat< T >	cv::cosh (const Quat< T > &q)
template<typename T>
Quat< T >	cv::crossProduct (const Quat< T > &p, const Quat< T > &q)
template<typename T>
Quat< T >	cv::exp (const Quat< T > &q)
template<typename T>
Quat< T >	cv::inv (const Quat< T > &q, QuatAssumeType assumeUnit=QUAT_ASSUME_NOT_UNIT)
template<typename T>
Quat< T >	cv::log (const Quat< T > &q, QuatAssumeType assumeUnit=QUAT_ASSUME_NOT_UNIT)
template<typename T, typename V>
static V	cv::operator* (const Affine3< T > &affine, const V &vector)
	V is a 3-element vector with member fields x, y and z.
template<typename T>
static Affine3< T >	cv::operator* (const Affine3< T > &affine1, const Affine3< T > &affine2)
static Vec3d	cv::operator* (const Affine3d &affine, const Vec3d &vector)
static Vec3f	cv::operator* (const Affine3f &affine, const Vec3f &vector)
template<typename T>
Quat< T >	cv::operator* (const Quat< T > &, const T)
template<typename T>
Quat< T >	cv::operator* (const T, const Quat< T > &)
template<typename _Tp>
std::ostream &	cv::operator<< (std::ostream &, const DualQuat< _Tp > &)
template<typename _Tp>
std::ostream &	cv::operator<< (std::ostream &, const Quat< _Tp > &)
template<typename S>
std::ostream &	cv::operator<< (std::ostream &, const Quat< S > &)
template<typename T>
Quat< T >	cv::power (const Quat< T > &q, const Quat< T > &p, QuatAssumeType assumeUnit=QUAT_ASSUME_NOT_UNIT)
template<typename T>
Quat< T >	cv::power (const Quat< T > &q, const T x, QuatAssumeType assumeUnit=QUAT_ASSUME_NOT_UNIT)
template<typename T>
Quat< T >	cv::sin (const Quat< T > &q)
template<typename T>
Quat< T >	cv::sinh (const Quat< T > &q)
template<typename S>
Quat< S >	cv::sqrt (const Quat< S > &q, QuatAssumeType assumeUnit=QUAT_ASSUME_NOT_UNIT)
void	cv::swap (Mat &a, Mat &b)
	Swaps two matrices.
void	cv::swap (UMat &a, UMat &b)
template<typename T>
Quat< T >	cv::tan (const Quat< T > &q)
template<typename T>
Quat< T >	cv::tanh (const Quat< T > &q)

Typedef Documentation

Affine3d

typedef Affine3<double> cv::Affine3d

#include <opencv2/core/affine.hpp>

Affine3f

typedef Affine3<float> cv::Affine3f

#include <opencv2/core/affine.hpp>

DualQuatd

using cv::DualQuatd = DualQuat<double>

#include <opencv2/core/dualquaternion.hpp>

DualQuatf

using cv::DualQuatf = DualQuat<float>

#include <opencv2/core/dualquaternion.hpp>

Quatd

using cv::Quatd = Quat<double>

#include <opencv2/core/quaternion.hpp>

Quatf

using cv::Quatf = Quat<float>

#include <opencv2/core/quaternion.hpp>

Enumeration Type Documentation

CovarFlags

enum cv::CovarFlags

#include <opencv2/core.hpp>

Covariation flags.

Enumerator
COVAR_SCRAMBLED  Python: cv.COVAR_SCRAMBLED	The output covariance matrix is calculated as: \[\texttt{scale} \cdot [ \texttt{vects} [0]- \texttt{mean} , \texttt{vects} [1]- \texttt{mean} ,...]^T \cdot [ \texttt{vects} [0]- \texttt{mean} , \texttt{vects} [1]- \texttt{mean} ,...],\] The covariance matrix will be nsamples x nsamples. Such an unusual covariance matrix is used for fast PCA of a set of very large vectors (see, for example, the EigenFaces technique for face recognition). Eigenvalues of this "scrambled" matrix match the eigenvalues of the true covariance matrix. The "true" eigenvectors can be easily calculated from the eigenvectors of the "scrambled" covariance matrix.
COVAR_NORMAL  Python: cv.COVAR_NORMAL	The output covariance matrix is calculated as: \[\texttt{scale} \cdot [ \texttt{vects} [0]- \texttt{mean} , \texttt{vects} [1]- \texttt{mean} ,...] \cdot [ \texttt{vects} [0]- \texttt{mean} , \texttt{vects} [1]- \texttt{mean} ,...]^T,\] covar will be a square matrix of the same size as the total number of elements in each input vector. One and only one of COVAR_SCRAMBLED and COVAR_NORMAL must be specified.
COVAR_USE_AVG  Python: cv.COVAR_USE_AVG	If the flag is specified, the function does not calculate mean from the input vectors but, instead, uses the passed mean vector. This is useful if mean has been pre-calculated or known in advance, or if the covariance matrix is calculated by parts. In this case, mean is not a mean vector of the input sub-set of vectors but rather the mean vector of the whole set.
COVAR_SCALE  Python: cv.COVAR_SCALE	If the flag is specified, the covariance matrix is scaled. In the "normal" mode, scale is 1./nsamples . In the "scrambled" mode, scale is the reciprocal of the total number of elements in each input vector. By default (if the flag is not specified), the covariance matrix is not scaled ( scale=1 ).
COVAR_ROWS  Python: cv.COVAR_ROWS	If the flag is specified, all the input vectors are stored as rows of the samples matrix. mean should be a single-row vector in this case.
COVAR_COLS  Python: cv.COVAR_COLS	If the flag is specified, all the input vectors are stored as columns of the samples matrix. mean should be a single-column vector in this case.

QuatAssumeType

enum cv::QuatAssumeType

#include <opencv2/core/quaternion.hpp>

Unit quaternion flag.

Enumerator
QUAT_ASSUME_NOT_UNIT  Python: cv.QUAT_ASSUME_NOT_UNIT	This flag is specified by default. If this flag is specified, the input quaternions are assumed to be not unit quaternions. It can guarantee the correctness of the calculations, although the calculation speed will be slower than the flag QUAT_ASSUME_UNIT.
QUAT_ASSUME_UNIT  Python: cv.QUAT_ASSUME_UNIT	If this flag is specified, the input quaternions are assumed to be unit quaternions which will save some computations. However, if this flag is specified without unit quaternion, the program correctness of the result will not be guaranteed.

Function Documentation

acos()

template<typename T>

Quat< T > cv::acos

(

const Quat< T > &

q

)

#include <opencv2/core/quaternion.hpp>

\[\arccos(q) = -\frac{\boldsymbol{v}}{||\boldsymbol{v}||}arccosh(q)\]

where \(\boldsymbol{v} = [x, y, z].\)

Parameters

q	a quaternion.

For example

Quatd q(1,2,3,4);
acos(q);

acosh()

template<typename T>

Quat< T > cv::acosh

(

const Quat< T > &

q

)

#include <opencv2/core/quaternion.hpp>

\[arccosh(q) = \ln(q + \sqrt{q^2 - 1})\]

.

Parameters

q	a quaternion.

For example

Quatd q(1,2,3,4);
acosh(q);

asin()

template<typename T>

Quat< T > cv::asin

(

const Quat< T > &

q

)

#include <opencv2/core/quaternion.hpp>

\[\arcsin(q) = -\frac{\boldsymbol{v}}{||\boldsymbol{v}||}arcsinh(q\frac{\boldsymbol{v}}{||\boldsymbol{v}||})\]

where \(\boldsymbol{v} = [x, y, z].\)

Parameters

q	a quaternion.

For example

Quatd q(1,2,3,4);
asin(q);

asinh()

template<typename T>

Quat< T > cv::asinh

(

const Quat< T > &

q

)

#include <opencv2/core/quaternion.hpp>

\[arcsinh(q) = \ln(q + \sqrt{q^2 + 1})\]

.

Parameters

q	a quaternion.

For example

Quatd q(1,2,3,4);
asinh(q);

atan()

template<typename T>

Quat< T > cv::atan

(

const Quat< T > &

q

)

#include <opencv2/core/quaternion.hpp>

\[\arctan(q) = -\frac{\boldsymbol{v}}{||\boldsymbol{v}||}arctanh(q\frac{\boldsymbol{v}}{||\boldsymbol{v}||})\]

where \(\boldsymbol{v} = [x, y, z].\)

Parameters

q	a quaternion.

For example

Quatd q(1,2,3,4);
atan(q);

atanh()

template<typename T>

Quat< T > cv::atanh

(

const Quat< T > &

q

)

#include <opencv2/core/quaternion.hpp>

\[arctanh(q) = \frac{\ln(q + 1) - \ln(1 - q)}{2}\]

.

Parameters

q	a quaternion.

For example

Quatd q(1,2,3,4);
atanh(q);

cos()

template<typename T>

Quat< T > cv::cos

(

const Quat< T > &

q

)

#include <opencv2/core/quaternion.hpp>

\[\cos(p) = \cos(w) * \cosh(||\boldsymbol{v}||) - \sin(w)\frac{\boldsymbol{v}}{||\boldsymbol{v}||}\sinh(||\boldsymbol{v}||)\]

where \(\boldsymbol{v} = [x, y, z].\)

Parameters

q	a quaternion.

For example

Quatd q(1,2,3,4);
cos(q);

Examples

samples/cpp/contours2.cpp, samples/cpp/image_alignment.cpp, samples/cpp/kalman.cpp, samples/cpp/polar_transforms.cpp, samples/cpp/tutorial_code/ImgTrans/houghlines.cpp, and samples/cpp/tutorial_code/ml/introduction_to_pca/introduction_to_pca.cpp.

cosh()

template<typename T>

Quat< T > cv::cosh

(

const Quat< T > &

q

)

#include <opencv2/core/quaternion.hpp>

\[\cosh(p) = \cosh(w) * \cos(||\boldsymbol{v}||) + \sinh(w)\frac{\boldsymbol{v}}{||\boldsymbol{v}||}\sin(||\boldsymbol{v}||)\]

where \(\boldsymbol{v} = [x, y, z].\)

Parameters

q	a quaternion.

For example

Quatd q(1,2,3,4);
cosh(q);

crossProduct()

template<typename T>

Quat< T > cv::crossProduct	(	const Quat< T > &	p,
		const Quat< T > &	q )

#include <opencv2/core/quaternion.hpp>

\[p \times q = \frac{pq- qp}{2}\]

\[p \times q = \boldsymbol{u} \times \boldsymbol{v}\]

\[p \times q = (cz-dy)i + (dx-bz)j + (by-xc)k \]

For example

Quatd q{1,2,3,4};
Quatd p{5,6,7,8};
crossProduct(p, q);

exp()

template<typename T>

Quat< T > cv::exp

(

const Quat< T > &

q

)

Python:
	cv.exp(	src[, dst]	) ->	dst

#include <opencv2/core/quaternion.hpp>

\[\exp(q) = e^w (\cos||\boldsymbol{v}||+ \frac{v}{||\boldsymbol{v}||})\sin||\boldsymbol{v}||\]

where \(\boldsymbol{v} = [x, y, z].\)

Parameters

q	a quaternion.

For example:

Quatd q{1,2,3,4};
cout << exp(q) << endl;

inv()

template<typename T>

Quat< T > cv::inv	(	const Quat< T > &	q,
		QuatAssumeType	assumeUnit = QUAT_ASSUME_NOT_UNIT )

#include <opencv2/core/quaternion.hpp>

Parameters

q	a quaternion.
assumeUnit	if QUAT_ASSUME_UNIT, quaternion q assume to be a unit quaternion and this function will save some computations.

For example

Quatd q(1,2,3,4);
inv(q);
 
QuatAssumeType assumeUnit = QUAT_ASSUME_UNIT;
q = q.normalize();
inv(q, assumeUnit);//This assumeUnit means p is a unit quaternion

log()

template<typename T>

Quat< T > cv::log	(	const Quat< T > &	q,
		QuatAssumeType	assumeUnit = QUAT_ASSUME_NOT_UNIT )

Python:
	cv.log(	src[, dst]	) ->	dst

#include <opencv2/core/quaternion.hpp>

\[\ln(q) = \ln||q|| + \frac{\boldsymbol{v}}{||\boldsymbol{v}||}\arccos\frac{w}{||q||}.\]

where \(\boldsymbol{v} = [x, y, z].\)

Parameters

q	a quaternion.
assumeUnit	if QUAT_ASSUME_UNIT, q assume to be a unit quaternion and this function will save some computations.

For example

Quatd q1{1,2,3,4};
cout << log(q1) << endl;

operator*() [1/6]

template<typename T, typename V>

V cv::operator* ( const Affine3< T > & affine, const V & vector )

static

#include <opencv2/core/affine.hpp>

V is a 3-element vector with member fields x, y and z.

operator*() [2/6]

template<typename T>

Affine3< T > cv::operator* ( const Affine3< T > & affine1, const Affine3< T > & affine2 )

static

#include <opencv2/core/affine.hpp>

operator*() [3/6]

Vec3d cv::operator* ( const Affine3d & affine, const Vec3d & vector )

static

#include <opencv2/core/affine.hpp>

operator*() [4/6]

Vec3f cv::operator* ( const Affine3f & affine, const Vec3f & vector )

static

#include <opencv2/core/affine.hpp>

operator*() [5/6]

template<typename T>

Quat< T > cv::operator*	(	const Quat< T > &	,
		const T	)

#include <opencv2/core/quaternion.hpp>

operator*() [6/6]

template<typename T>

Quat< T > cv::operator*	(	const T	,
		const Quat< T > &	)

#include <opencv2/core/quaternion.hpp>

operator<<() [1/3]

template<typename _Tp>

std::ostream & cv::operator<<	(	std::ostream &	,
		const DualQuat< _Tp > &	)

#include <opencv2/core/dualquaternion.hpp>

operator<<() [2/3]

template<typename _Tp>

std::ostream & cv::operator<<	(	std::ostream &	,
		const Quat< _Tp > &	)

#include <opencv2/core/quaternion.hpp>

operator<<() [3/3]

template<typename S>

std::ostream & cv::operator<<	(	std::ostream &	,
		const Quat< S > &	)

#include <opencv2/core/quaternion.hpp>

power() [1/2]

template<typename T>

Quat< T > cv::power	(	const Quat< T > &	q,
		const Quat< T > &	p,
		QuatAssumeType	assumeUnit = QUAT_ASSUME_NOT_UNIT )

#include <opencv2/core/quaternion.hpp>

\[p^q = e^{q\ln(p)}.\]

Parameters

p	base quaternion of power function.
q	index quaternion of power function.
assumeUnit	if QUAT_ASSUME_UNIT, quaternion \(p\) assume to be a unit quaternion and this function will save some computations.

For example

Quatd p(1,2,3,4);
Quatd q(5,6,7,8);
power(p, q);
 
QuatAssumeType assumeUnit = QUAT_ASSUME_UNIT;
p = p.normalize();
power(p, q, assumeUnit); //This assumeUnit means p is a unit quaternion

power() [2/2]

template<typename T>

Quat< T > cv::power	(	const Quat< T > &	q,
		const T	x,
		QuatAssumeType	assumeUnit = QUAT_ASSUME_NOT_UNIT )

#include <opencv2/core/quaternion.hpp>

\[q^x = ||q||(cos(x\theta) + \boldsymbol{u}sin(x\theta))).\]

Parameters

q	a quaternion.
x	index of exponentiation.
assumeUnit	if QUAT_ASSUME_UNIT, quaternion q assume to be a unit quaternion and this function will save some computations.

For example

Quatd q(1,2,3,4);
power(q, 2.0);
 
QuatAssumeType assumeUnit = QUAT_ASSUME_UNIT;
double angle = CV_PI;
Vec3d axis{0, 0, 1};
Quatd q1 = Quatd::createFromAngleAxis(angle, axis); //generate a unit quat by axis and angle
power(q1, 2.0, assumeUnit);//This assumeUnit means q1 is a unit quaternion.

Note

the type of the index should be the same as the quaternion.

sin()

template<typename T>

Quat< T > cv::sin

(

const Quat< T > &

q

)

#include <opencv2/core/quaternion.hpp>

\[\sin(p) = \sin(w) * \cosh(||\boldsymbol{v}||) + \cos(w)\frac{\boldsymbol{v}}{||\boldsymbol{v}||}\sinh(||\boldsymbol{v}||)\]

where \(\boldsymbol{v} = [x, y, z].\)

Parameters

q	a quaternion.

For example

Quatd q(1,2,3,4);
sin(q);

Examples

samples/cpp/contours2.cpp, samples/cpp/image_alignment.cpp, samples/cpp/kalman.cpp, samples/cpp/polar_transforms.cpp, samples/cpp/tutorial_code/ImgTrans/houghlines.cpp, and samples/cpp/tutorial_code/ml/introduction_to_pca/introduction_to_pca.cpp.

sinh()

template<typename T>

Quat< T > cv::sinh

(

const Quat< T > &

q

)

#include <opencv2/core/quaternion.hpp>

\[\sinh(p) = \sin(w)\cos(||\boldsymbol{v}||) + \cosh(w)\frac{v}{||\boldsymbol{v}||}\sin||\boldsymbol{v}||\]

where \(\boldsymbol{v} = [x, y, z].\)

Parameters

q	a quaternion.

For example

Quatd q(1,2,3,4);
sinh(q);

sqrt()

template<typename S>

Quat< S > cv::sqrt	(	const Quat< S > &	q,
		QuatAssumeType	assumeUnit = QUAT_ASSUME_NOT_UNIT )

Python:
	cv.sqrt(	src[, dst]	) ->	dst

#include <opencv2/core/quaternion.hpp>

swap() [1/2]

void cv::swap	(	Mat &	a,
		Mat &	b )

#include <opencv2/core.hpp>

Swaps two matrices.

Examples

samples/cpp/lkdemo.cpp, and samples/cpp/warpPerspective_demo.cpp.

swap() [2/2]

void cv::swap	(	UMat &	a,
		UMat &	b )

#include <opencv2/core.hpp>

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

tan()

template<typename T>

Quat< T > cv::tan

(

const Quat< T > &

q

)

#include <opencv2/core/quaternion.hpp>

\[\tan(q) = \frac{\sin(q)}{\cos(q)}.\]

Parameters

q	a quaternion.

For example

Quatd q(1,2,3,4);
tan(q);

tanh()

template<typename T>

Quat< T > cv::tanh

(

const Quat< T > &

q

)

#include <opencv2/core/quaternion.hpp>

\[ \tanh(q) = \frac{\sinh(q)}{\cosh(q)}.\]

Parameters

q	a quaternion.

For example

Quatd q(1,2,3,4);
tanh(q);

See also

sinh, cosh