org.bytedeco.opencv.opencv_core

Class MatExpr

java.lang.Object

org.bytedeco.javacpp.Pointer

org.bytedeco.opencv.opencv_core.MatExpr

All Implemented Interfaces:

AutoCloseable

@Namespace(value="cv")
 @NoOffset
 @Properties(inherit=opencv_core.class)
public class MatExpr
extends Pointer

\brief Matrix expression representation \anchor MatrixExpressions This is a list of implemented matrix operations that can be combined in arbitrary complex expressions (here A, B stand for matrices ( Mat ), s for a scalar ( 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: min(A, B), min(A, alpha), max(A, B), max(A, alpha) - Element-wise absolute value: 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 norm, mean, sum, countNonZero, trace, determinant, repeat, and others. - Matrix initializers ( Mat::eye(), Mat::zeros(), Mat::ones() ), matrix comma-separated initializers, matrix constructors and operators that extract sub-matrices (see Mat description). - Mat_() constructors to cast the result to the proper type. \note Comma-separated initializers and probably some other operations may require additional explicit Mat() or Mat_() constructor calls to resolve a possible ambiguity.

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);

Nested Class Summary

Nested classes/interfaces inherited from class org.bytedeco.javacpp.Pointer

Pointer.CustomDeallocator, Pointer.Deallocator, Pointer.NativeDeallocator, Pointer.ReferenceCounter

Field Summary

Fields inherited from class org.bytedeco.javacpp.Pointer

address, capacity, limit, position

Constructor Summary

Constructors

Constructor and Description
MatExpr()
MatExpr(long size) Native array allocator.
MatExpr(Mat m)
MatExpr(MatOp _op, int _flags)
MatExpr(MatOp _op, int _flags, Mat _a, Mat _b, Mat _c, double _alpha, double _beta, Scalar _s)
MatExpr(Pointer p) Pointer cast constructor.

Method Summary

Modifier and Type	Method and Description
Mat	a()
MatExpr	a(Mat setter)
double	alpha()
MatExpr	alpha(double setter)
MatExpr	apply(Range rowRange, Range colRange)
MatExpr	apply(Rect roi)
Mat	asMat()
Mat	b()
MatExpr	b(Mat setter)
double	beta()
MatExpr	beta(double setter)
Mat	c()
MatExpr	c(Mat setter)
MatExpr	col(int x)
Mat	cross(Mat m)
MatExpr	diag()
MatExpr	diag(int d)
double	dot(Mat m)
int	flags()
MatExpr	flags(int setter)
MatExpr	inv()
MatExpr	inv(int method)
MatExpr	mul(Mat m)
MatExpr	mul(Mat m, double scale)
MatExpr	mul(MatExpr e)
MatExpr	mul(MatExpr e, double scale)
MatOp	op()
MatExpr	op(MatOp setter)
MatExpr	position(long position)
MatExpr	row(int y)
Scalar	s()
MatExpr	s(Scalar setter)
Size	size()
MatExpr	t()
int	type()

Methods inherited from class org.bytedeco.javacpp.Pointer

address, asBuffer, asByteBuffer, availablePhysicalBytes, calloc, capacity, capacity, close, deallocate, deallocate, deallocateReferences, deallocator, deallocator, equals, fill, formatBytes, free, hashCode, isNull, isNull, limit, limit, malloc, maxBytes, maxPhysicalBytes, memchr, memcmp, memcpy, memmove, memset, offsetof, parseBytes, physicalBytes, position, put, realloc, referenceCount, releaseReference, retainReference, setNull, sizeof, toString, totalBytes, totalPhysicalBytes, withDeallocator, zero

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

MatExpr

public MatExpr(Pointer p)

Pointer cast constructor. Invokes Pointer.Pointer(Pointer).

MatExpr

public MatExpr(long size)

Native array allocator. Access with Pointer.position(long).

MatExpr

public MatExpr()

MatExpr

public MatExpr(@Const @ByRef
               Mat m)

MatExpr

public MatExpr(@Const
               MatOp _op,
               int _flags,
               @Const @ByRef(nullValue="cv::Mat()")
               Mat _a,
               @Const @ByRef(nullValue="cv::Mat()")
               Mat _b,
               @Const @ByRef(nullValue="cv::Mat()")
               Mat _c,
               double _alpha,
               double _beta,
               @Const @ByRef(nullValue="cv::Scalar()")
               Scalar _s)

MatExpr

public MatExpr(@Const
               MatOp _op,
               int _flags)

Method Detail

position

public MatExpr position(long position)

Overrides:

position in class Pointer

asMat

@ByVal
 @Name(value="operator cv::Mat")
public Mat asMat()

size

@ByVal
public Size size()

type

public int type()

row

@ByVal
public MatExpr row(int y)

col

@ByVal
public MatExpr col(int x)

diag

@ByVal
public MatExpr diag(int d)

diag

@ByVal
public MatExpr diag()

apply

@ByVal
 @Name(value="operator ()")
public MatExpr apply(@Const @ByRef
                                                        Range rowRange,
                                                        @Const @ByRef
                                                        Range colRange)

apply

@ByVal
 @Name(value="operator ()")
public MatExpr apply(@Const @ByRef
                                                        Rect roi)

t

@ByVal
public MatExpr t()

inv

@ByVal
public MatExpr inv(int method)

inv

@ByVal
public MatExpr inv()

mul

@ByVal
public MatExpr mul(@Const @ByRef
                          MatExpr e,
                          double scale)

mul

@ByVal
public MatExpr mul(@Const @ByRef
                          MatExpr e)

mul

@ByVal
public MatExpr mul(@Const @ByRef
                          Mat m,
                          double scale)

mul

@ByVal
public MatExpr mul(@Const @ByRef
                          Mat m)

cross

@ByVal
public Mat cross(@Const @ByRef
                        Mat m)

dot

public double dot(@Const @ByRef
                  Mat m)

op

@Const
public MatOp op()

op

public MatExpr op(MatOp setter)

flags

public int flags()

flags

public MatExpr flags(int setter)

a

@ByRef
public Mat a()

a

public MatExpr a(Mat setter)

b

@ByRef
public Mat b()

b

public MatExpr b(Mat setter)

c

@ByRef
public Mat c()

c

public MatExpr c(Mat setter)

alpha

public double alpha()

alpha

public MatExpr alpha(double setter)

beta

public double beta()

beta

public MatExpr beta(double setter)

s

@ByRef
public Scalar s()

s

public MatExpr s(Scalar setter)