Class cv::MatExpr

Matrix expression representation This is a list of implemented matrix operations that can be combined in arbitrary complex expressions (here A, B stand for matrices ( cv::Mat ), s for a cv::Scalar, alpha for a real-valued scalar ( double )): View details

#include <opencv2/core/mat.hpp>

Collaboration diagram for cv::MatExpr:

Detailed Description

Matrix expression representation This is a list of implemented matrix operations that can be combined in arbitrary complex expressions (here A, B stand for matrices ( cv::Mat ), s for a cv::Scalar, alpha for a real-valued scalar ( double )):

• Addition, subtraction, negation: A+B, A-B, A+s, A-s, s+A, s-A, -A

• Scaling: A*alpha

• Per-element multiplication and division: A.mul(B), A/B, alpha/A

• Matrix multiplication: A*B

• Transposition: A.t() (means A^T)

• Matrix inversion and pseudo-inversion, solving linear systems and least-squares problems: A.inv([method]) (~ A<sup>-1</sup>), A.inv([method])*B (~ X: AX=B)

• Comparison: A cmpop B, A cmpop alpha, alpha cmpop A, where cmpop is one of >, >=, ==, !=, <=, <. The result of comparison is an 8-bit single channel mask whose elements are set to 255 (if the particular element or pair of elements satisfy the condition) or 0.

• Bitwise logical operations: A logicop B, A logicop s, s logicop A, ~A, where logicop is one of &, |, ^.

• Element-wise minimum and maximum: cv::min(A, B), cv::min(A, alpha), cv::max(A, B), cv::max(A, alpha)

• Element-wise absolute value: cv::abs(A)

• Cross-product, dot-product: A.cross(B), A.dot(B)

• Any function of matrix or matrices and scalars that returns a matrix or a scalar, such as cv::norm, cv::mean, cv::sum, cv::countNonZero, cv::trace, cv::determinant, cv::repeat, and others.

• Matrix initializers ( Mat::eye(), Mat::zeros(), Mat::ones() ), matrix comma-separated initializers, matrix constructors and operators that extract sub-matrices (see cv::Mat description).

• Mat_<destination_type>() constructors to cast the result to the proper type.

  Here are examples of matrix expressions:

  // compute pseudo-inverse of A, equivalent to A.inv(DECOMP_SVD)
  SVD svd(A);
  Mat pinvA = svd.vt.t()*Mat::diag(1./svd.w)*svd.u.t();
  
  // compute the new vector of parameters in the Levenberg-Marquardt algorithm
  x -= (A.t()*A + lambda*Mat::eye(A.cols,A.cols,A.type())).inv(DECOMP_CHOLESKY)*(A.t()*err);
  
  // sharpen image using "unsharp mask" algorithm
  Mat blurred; double sigma = 1, threshold = 5, amount = 1;
  GaussianBlur(img, blurred, Size(), sigma, sigma);
  Mat lowContrastMask = abs(img - blurred) < threshold;
  Mat sharpened = img*(1+amount) + blurred*(-amount);
  img.copyTo(sharpened, lowContrastMask);
  

Note

Comma-separated initializers and probably some other operations may require additional explicit Mat() or Mat_<T>() constructor calls to resolve a possible ambiguity.

Constructor & Destructor Documentation

MatExpr()

cv::MatExpr::MatExpr()

MatExpr()

cv::MatExpr::MatExpr(const Mat & m)

MatExpr()

cv::MatExpr::MatExpr(
const MatOp * _op,
int _flags,
const Mat & _a = Mat(),
const Mat & _b = Mat(),
const Mat & _c = Mat(),
double _alpha = 1,
double _beta = 1,
const Scalar & _s = Scalar() )

Member Function Documentation

operator+()

MatExpr cv::MatExpr::operator+(
const Mat & a,
const Mat & b )

operator+()

MatExpr cv::MatExpr::operator+(
const Mat & a,
const Scalar & s )

operator+()

MatExpr cv::MatExpr::operator+(
const Scalar & s,
const Mat & a )

operator+()

MatExpr cv::MatExpr::operator+(
const MatExpr & e,
const Mat & m )

operator+()

MatExpr cv::MatExpr::operator+(
const Mat & m,
const MatExpr & e )

operator+()

MatExpr cv::MatExpr::operator+(
const MatExpr & e,
const Scalar & s )

operator+()

MatExpr cv::MatExpr::operator+(
const Scalar & s,
const MatExpr & e )

operator+()

MatExpr cv::MatExpr::operator+(
const MatExpr & e1,
const MatExpr & e2 )

operator+()

template<typename _Tp, int m, int n>
static MatExpr cv::MatExpr::operator+(
const Mat & a,
const Matx< _Tp, m, n > & b )

operator+()

template<typename _Tp, int m, int n>
static MatExpr cv::MatExpr::operator+(
const Matx< _Tp, m, n > & a,
const Mat & b )

operator-()

MatExpr cv::MatExpr::operator-(
const Mat & a,
const Mat & b )

operator-()

MatExpr cv::MatExpr::operator-(
const Mat & a,
const Scalar & s )

operator-()

MatExpr cv::MatExpr::operator-(
const Scalar & s,
const Mat & a )

operator-()

MatExpr cv::MatExpr::operator-(
const MatExpr & e,
const Mat & m )

operator-()

MatExpr cv::MatExpr::operator-(
const Mat & m,
const MatExpr & e )

operator-()

MatExpr cv::MatExpr::operator-(
const MatExpr & e,
const Scalar & s )

operator-()

MatExpr cv::MatExpr::operator-(
const Scalar & s,
const MatExpr & e )

operator-()

MatExpr cv::MatExpr::operator-(
const MatExpr & e1,
const MatExpr & e2 )

operator-()

template<typename _Tp, int m, int n>
static MatExpr cv::MatExpr::operator-(
const Mat & a,
const Matx< _Tp, m, n > & b )

operator-()

template<typename _Tp, int m, int n>
static MatExpr cv::MatExpr::operator-(
const Matx< _Tp, m, n > & a,
const Mat & b )

operator-()

MatExpr cv::MatExpr::operator-(const Mat & m)

operator-()

MatExpr cv::MatExpr::operator-(const MatExpr & e)

operator*()

MatExpr cv::MatExpr::operator*(
const Mat & a,
const Mat & b )

operator*()

MatExpr cv::MatExpr::operator*(
const Mat & a,
double s )

operator*()

MatExpr cv::MatExpr::operator*(
double s,
const Mat & a )

operator*()

MatExpr cv::MatExpr::operator*(
const MatExpr & e,
const Mat & m )

operator*()

MatExpr cv::MatExpr::operator*(
const Mat & m,
const MatExpr & e )

operator*()

MatExpr cv::MatExpr::operator*(
const MatExpr & e,
double s )

operator*()

MatExpr cv::MatExpr::operator*(
double s,
const MatExpr & e )

operator*()

MatExpr cv::MatExpr::operator*(
const MatExpr & e1,
const MatExpr & e2 )

operator*()

template<typename _Tp, int m, int n>
static MatExpr cv::MatExpr::operator*(
const Mat & a,
const Matx< _Tp, m, n > & b )

operator*()

template<typename _Tp, int m, int n>
static MatExpr cv::MatExpr::operator*(
const Matx< _Tp, m, n > & a,
const Mat & b )

operator/()

MatExpr cv::MatExpr::operator/(
const Mat & a,
const Mat & b )

operator/()

MatExpr cv::MatExpr::operator/(
const Mat & a,
double s )

operator/()

MatExpr cv::MatExpr::operator/(
double s,
const Mat & a )

operator/()

MatExpr cv::MatExpr::operator/(
const MatExpr & e,
const Mat & m )

operator/()

MatExpr cv::MatExpr::operator/(
const Mat & m,
const MatExpr & e )

operator/()

MatExpr cv::MatExpr::operator/(
const MatExpr & e,
double s )

operator/()

MatExpr cv::MatExpr::operator/(
double s,
const MatExpr & e )

operator/()

MatExpr cv::MatExpr::operator/(
const MatExpr & e1,
const MatExpr & e2 )

operator/()

template<typename _Tp, int m, int n>
static MatExpr cv::MatExpr::operator/(
const Mat & a,
const Matx< _Tp, m, n > & b )

operator/()

template<typename _Tp, int m, int n>
static MatExpr cv::MatExpr::operator/(
const Matx< _Tp, m, n > & a,
const Mat & b )

operator<()

MatExpr cv::MatExpr::operator<(
const Mat & a,
const Mat & b )

operator<()

MatExpr cv::MatExpr::operator<(
const Mat & a,
double s )

operator<()

MatExpr cv::MatExpr::operator<(
double s,
const Mat & a )

operator<()

template<typename _Tp, int m, int n>
static MatExpr cv::MatExpr::operator<(
const Mat & a,
const Matx< _Tp, m, n > & b )

operator<()

template<typename _Tp, int m, int n>
static MatExpr cv::MatExpr::operator<(
const Matx< _Tp, m, n > & a,
const Mat & b )

operator<=()

MatExpr cv::MatExpr::operator<=(
const Mat & a,
const Mat & b )

operator<=()

MatExpr cv::MatExpr::operator<=(
const Mat & a,
double s )

operator<=()

MatExpr cv::MatExpr::operator<=(
double s,
const Mat & a )

operator<=()

template<typename _Tp, int m, int n>
static MatExpr cv::MatExpr::operator<=(
const Mat & a,
const Matx< _Tp, m, n > & b )

operator<=()

template<typename _Tp, int m, int n>
static MatExpr cv::MatExpr::operator<=(
const Matx< _Tp, m, n > & a,
const Mat & b )

operator==()

MatExpr cv::MatExpr::operator==(
const Mat & a,
const Mat & b )

operator==()

MatExpr cv::MatExpr::operator==(
const Mat & a,
double s )

operator==()

MatExpr cv::MatExpr::operator==(
double s,
const Mat & a )

operator==()

template<typename _Tp, int m, int n>
static MatExpr cv::MatExpr::operator==(
const Mat & a,
const Matx< _Tp, m, n > & b )

operator==()

template<typename _Tp, int m, int n>
static MatExpr cv::MatExpr::operator==(
const Matx< _Tp, m, n > & a,
const Mat & b )

operator!=()

MatExpr cv::MatExpr::operator!=(
const Mat & a,
const Mat & b )

operator!=()

MatExpr cv::MatExpr::operator!=(
const Mat & a,
double s )

operator!=()

MatExpr cv::MatExpr::operator!=(
double s,
const Mat & a )

operator!=()

template<typename _Tp, int m, int n>
static MatExpr cv::MatExpr::operator!=(
const Mat & a,
const Matx< _Tp, m, n > & b )

operator!=()

template<typename _Tp, int m, int n>
static MatExpr cv::MatExpr::operator!=(
const Matx< _Tp, m, n > & a,
const Mat & b )

operator>=()

MatExpr cv::MatExpr::operator>=(
const Mat & a,
const Mat & b )

operator>=()

MatExpr cv::MatExpr::operator>=(
const Mat & a,
double s )

operator>=()

MatExpr cv::MatExpr::operator>=(
double s,
const Mat & a )

operator>=()

template<typename _Tp, int m, int n>
static MatExpr cv::MatExpr::operator>=(
const Mat & a,
const Matx< _Tp, m, n > & b )

operator>=()

template<typename _Tp, int m, int n>
static MatExpr cv::MatExpr::operator>=(
const Matx< _Tp, m, n > & a,
const Mat & b )

operator>()

MatExpr cv::MatExpr::operator>(
const Mat & a,
const Mat & b )

operator>()

MatExpr cv::MatExpr::operator>(
const Mat & a,
double s )

operator>()

MatExpr cv::MatExpr::operator>(
double s,
const Mat & a )

operator>()

template<typename _Tp, int m, int n>
static MatExpr cv::MatExpr::operator>(
const Mat & a,
const Matx< _Tp, m, n > & b )

operator>()

template<typename _Tp, int m, int n>
static MatExpr cv::MatExpr::operator>(
const Matx< _Tp, m, n > & a,
const Mat & b )

operator&()

MatExpr cv::MatExpr::operator&(
const Mat & a,
const Mat & b )

operator&()

MatExpr cv::MatExpr::operator&(
const Mat & a,
const Scalar & s )

operator&()

MatExpr cv::MatExpr::operator&(
const Scalar & s,
const Mat & a )

operator&()

template<typename _Tp, int m, int n>
static MatExpr cv::MatExpr::operator&(
const Mat & a,
const Matx< _Tp, m, n > & b )

operator&()

template<typename _Tp, int m, int n>
static MatExpr cv::MatExpr::operator&(
const Matx< _Tp, m, n > & a,
const Mat & b )

operator|()

MatExpr cv::MatExpr::operator|(
const Mat & a,
const Mat & b )

operator|()

MatExpr cv::MatExpr::operator|(
const Mat & a,
const Scalar & s )

operator|()

MatExpr cv::MatExpr::operator|(
const Scalar & s,
const Mat & a )

operator|()

template<typename _Tp, int m, int n>
static MatExpr cv::MatExpr::operator|(
const Mat & a,
const Matx< _Tp, m, n > & b )

operator|()

template<typename _Tp, int m, int n>
static MatExpr cv::MatExpr::operator|(
const Matx< _Tp, m, n > & a,
const Mat & b )

operator^()

MatExpr cv::MatExpr::operator^(
const Mat & a,
const Mat & b )

operator^()

MatExpr cv::MatExpr::operator^(
const Mat & a,
const Scalar & s )

operator^()

MatExpr cv::MatExpr::operator^(
const Scalar & s,
const Mat & a )

operator^()

template<typename _Tp, int m, int n>
static MatExpr cv::MatExpr::operator^(
const Mat & a,
const Matx< _Tp, m, n > & b )

operator^()

template<typename _Tp, int m, int n>
static MatExpr cv::MatExpr::operator^(
const Matx< _Tp, m, n > & a,
const Mat & b )

operator~()

MatExpr cv::MatExpr::operator~(const Mat & m)

min()

MatExpr cv::MatExpr::min(
const Mat & a,
const Mat & b )

min()

MatExpr cv::MatExpr::min(
const Mat & a,
double s )

min()

MatExpr cv::MatExpr::min(
double s,
const Mat & a )

min()

template<typename _Tp, int m, int n>
static MatExpr cv::MatExpr::min(
const Mat & a,
const Matx< _Tp, m, n > & b )

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min()

template<typename _Tp, int m, int n>
static MatExpr cv::MatExpr::min(
const Matx< _Tp, m, n > & a,
const Mat & b )

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max()

MatExpr cv::MatExpr::max(
const Mat & a,
const Mat & b )

max()

MatExpr cv::MatExpr::max(
const Mat & a,
double s )

max()

MatExpr cv::MatExpr::max(
double s,
const Mat & a )

max()

template<typename _Tp, int m, int n>
static MatExpr cv::MatExpr::max(
const Mat & a,
const Matx< _Tp, m, n > & b )

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max()

template<typename _Tp, int m, int n>
static MatExpr cv::MatExpr::max(
const Matx< _Tp, m, n > & a,
const Mat & b )

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abs()

MatExpr cv::MatExpr::abs(const Mat & m)

Calculates an absolute value of each matrix element.

abs is a meta-function that is expanded to one of absdiff or convertScaleAbs forms:

• C = abs(A-B) is equivalent to absdiff(A, B, C)

• C = abs(A) is equivalent to absdiff(A, Scalar::all(0), C)

• C = Mat_<Vec<uchar,n> >(abs(A*alpha + beta)) is equivalent to convertScaleAbs(A, C, alpha, beta)

The output matrix has the same size and the same type as the input one except for the last case, where C is depth=CV_8U .

See also

MatrixExpressions, absdiff, convertScaleAbs

Parameters

• m — matrix.

abs()

MatExpr cv::MatExpr::abs(const MatExpr & e)

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

Parameters

• e — matrix expression.

col()

MatExpr cv::MatExpr::col(int x)

cross()

Mat cv::MatExpr::cross(const Mat & m)

diag()

MatExpr cv::MatExpr::diag(int d = 0)

dot()

double cv::MatExpr::dot(const Mat & m)

inv()

MatExpr cv::MatExpr::inv(int method = DECOMP_LU)

mul()

MatExpr cv::MatExpr::mul(
const Mat & m,
double scale = 1 )

mul()

MatExpr cv::MatExpr::mul(
const MatExpr & e,
double scale = 1 )

operator Mat()

cv::MatExpr::operator Mat()

operator Mat_< _Tp >()

template<typename _Tp>
cv::MatExpr::operator Mat_< _Tp >()

operator()()

MatExpr cv::MatExpr::operator()(
const Range & rowRange,
const Range & colRange )

operator()()

MatExpr cv::MatExpr::operator()(const Rect & roi)

row()

MatExpr cv::MatExpr::row(int y)

size()

Size cv::MatExpr::size()

swap()

void cv::MatExpr::swap(MatExpr & b)

t()

MatExpr cv::MatExpr::t()

type()

int cv::MatExpr::type()

Member Data Documentation

a

Mat cv::MatExpr::a

alpha

double cv::MatExpr::alpha

b

Mat cv::MatExpr::b

beta

double cv::MatExpr::beta

c

Mat cv::MatExpr::c

flags

int cv::MatExpr::flags

op

const MatOp * cv::MatExpr::op

s

Scalar cv::MatExpr::s

Source file

The documentation for this class was generated from the following file:

• opencv2/core/mat.hpp