Mat class

Inheritance

• Object
• CvObject<Mat>
• ICvStruct<Mat>
• CvStruct<Mat>
• Mat

Available extensions

• MatAsync

Constructors

Mat.create({int rows = 0, int cols = 0, int r = 0, int g = 0, int b = 0, MatType? type})

factory

Mat.empty()

factory

Mat.eye(int rows, int cols, MatType type)

Returns an identity matrix of the specified size and type.

factory

Mat.from2DList(Iterable<Iterable<num>> data, MatType type, {int? cols, int? rows})

Create a Mat from a 2D list

factory

Mat.from3DList(Iterable<Iterable<Iterable<num>>> data, MatType type)

Create a Mat from a 3D list

factory

Mat.fromBuffer(int rows, int cols, MatType type, Pointer<Void> buff)

Create a Mat from self-allocated buffer

factory

Mat.fromList(int rows, int cols, MatType type, List<num> data)

Create a Mat from a list of data

factory

Mat.fromMat(Mat mat, {bool copy = false, Rect? roi})

create a Mat reference from another Mat if copy is false, otherwise a copy will be created.

factory

Mat.fromPointer(MatPtr mat, {bool attach = true, int? externalSize})

construct from pointer directly

factory

Mat.fromRange(Mat mat, int rowStart, int rowEnd, {int colStart = 0, int? colEnd})

Create Mat from another Mat with range

factory

Mat.fromScalar(int rows, int cols, MatType type, Scalar s)

rows Number of rows in a 2D array.

factory

Mat.fromVec(Vec<Struct, dynamic> vec, {int? rows, int? cols, MatType? type, bool copyData = true})

Create Mat from a vector Vec

factory

Mat.ones(int rows, int cols, MatType type)

Returns an array of all 1's of the specified size and type.

factory

Mat.randn(int rows, int cols, MatType type, {Scalar? mean, Scalar? std})

factory

Mat.randu(int rows, int cols, MatType type, {Scalar? low, Scalar? high})

factory

Mat.zeros(int rows, int cols, MatType type)

Returns a zero array of the specified size and type.

factory

Properties

channels → int

no setter

cols → int

no setter

countNoneZero → int

only for channels == 1

no setter

data → Uint8List

Get a view of native data.

no setter

dataPtr → Pointer<U8>

Get the data pointer of the Mat

no setter

dims → int

no setter

elemSize → int

Returns the matrix element size in bytes.

no setter

elemSize1 → int

Returns the size of each matrix element channel in bytes.

no setter

flags → int

no setter

hashCode → int

The hash code for this object.

no setter, inherited

height → int

no setter

isContinuous → bool

no setter

isDisposed → bool

Whether this object has been disposed.

no setter, inherited

isEmpty → bool

no setter

isSubmatrix → bool

no setter

props → List<Object?>

no setter, inherited

ptr ↔ Pointer<Mat>

getter/setter pair, inherited

ref → Mat

no setter, override

rows → int

no setter

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

shape → List<int>

(rows, cols, channels)

no setter

size → VecI32

Mat.size

no setter

step → (int, int, int)

no setter

total → int

no setter

type → MatType

no setter

width → int

no setter

Methods

add<T>(T val, {bool inplace = false}) → Mat

add

addF32(double val, {bool inplace = false}) → Mat

addF64(double val, {bool inplace = false}) → Mat

addI16(int val, {bool inplace = false}) → Mat

addI32(int val, {bool inplace = false}) → Mat

addI8(int val, {bool inplace = false}) → Mat

addMat(Mat other, {bool inplace = false}) → Mat

addU16(int val, {bool inplace = false}) → Mat

addU8(int val, {bool inplace = false}) → Mat

adjustROI(int dtop, int dbottom, int dleft, int dright) → Mat

Adjusts a submatrix size and position within the parent matrix.

at<T>(int i0, int i1, [int? i2]) → T

cv::Mat::at<T>(i0, i1, i2) of cv::Mat

atF32(int i0, {int? i1, int? i2}) → double

atF64(int i0, {int? i1, int? i2}) → double

atI16(int i0, {int? i1, int? i2}) → int

atI32(int i0, {int? i1, int? i2}) → int

atI8(int i0, {int? i1, int? i2}) → int

atNum(int i0, int i1, {int? i2, MatType? mtype}) → num

wrapper of cv::Mat::at()

atPixel(int row, int col, {MatType? mtype}) → List<num>

Get pixel value via row, col, returns a view of native data

atU16(int i0, {int? i1, int? i2}) → int

atU8(int i0, {int? i1, int? i2}) → int

atVec<T>(int row, int col) → T

clone() → Mat

cloneAsync() → Future<Mat>

Available on Mat, provided by the MatAsync extension

col(int x) → Mat

Creates a matrix header for the specified matrix column.

colRange(int start, int end) → Mat

Creates a matrix header for the specified column span.

colRangeAsync(int start, int end) → Future<Mat>

Available on Mat, provided by the MatAsync extension

convertTo(MatType type, {bool inplace = false, double alpha = 1, double beta = 0}) → Mat

Converts an array to another data type with optional scaling.

convertToAsync(MatType type, {double alpha = 1, double beta = 0}) → Future<Mat>

Available on Mat, provided by the MatAsync extension

convertToFp16() → Mat

copyTo(Mat dst, {Mat? mask}) → void

Copies the matrix to another one.

copyToAsync(Mat dst, {Mat? mask}) → Future<void>

Available on Mat, provided by the MatAsync extension

dispose() → void

Releases the underlying native resources. Idempotent: calling it more than once is safe, but the object must not be used after dispose.

inherited

divide<T>(T val, {bool inplace = false}) → Mat

divide

divideF32(double val, {bool inplace = false}) → Mat

divideF64(double val, {bool inplace = false}) → Mat

divideI16(int val, {bool inplace = false}) → Mat

divideI32(int val, {bool inplace = false}) → Mat

divideI8(int val, {bool inplace = false}) → Mat

divideMat(Mat other, {bool inplace = false}) → Mat

divideU16(int val, {bool inplace = false}) → Mat

divideU8(int val, {bool inplace = false}) → Mat

forEachPixel(void callback(int row, int col, List<num> pixel)) → void

Iterate over all pixels in the Mat.

forEachRow(void callback(int row, List<num> values)) → void

Iterate over all rows in the Mat.

freeNative() → void

Frees the native resources owned by this object. Subclasses implement the concrete free logic here; callers must use dispose instead.

override

getUMat(AccessFlag accessFlags, {UMatUsageFlags usageFlags = UMatUsageFlags.USAGE_DEFAULT}) → UMat

retrieve UMat from Mat

isSubtype<S, T>() → bool

locateROI() → (Size, Point)

Locates the matrix header within a parent matrix.

mean({Mat? mask}) → Scalar

meanAsync({Mat? mask}) → Future<Scalar>

Available on Mat, provided by the MatAsync extension

mul(Mat other, {bool inplace = false, double scale = 1.0}) → Mat

Performs an element-wise multiplication or division of the two matrices.

multiply<T>(T val, {bool inplace = false}) → Mat

Multiply

multiplyF32(double val, {bool inplace = false}) → Mat

multiplyF64(double val, {bool inplace = false}) → Mat

multiplyI16(int val, {bool inplace = false}) → Mat

multiplyI32(int val, {bool inplace = false}) → Mat

multiplyI8(int val, {bool inplace = false}) → Mat

multiplyMat(Mat other, {bool inplace = false}) → Mat

Matrix multiplication

multiplyU16(int val, {bool inplace = false}) → Mat

multiplyU8(int val, {bool inplace = false}) → Mat

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

patchNaNs({double val = 0}) → void

PatchNaNs converts NaN's to zeros.

patchNaNsAsync({double val = 0.0}) → Future<void>

Available on Mat, provided by the MatAsync extension

PatchNaNs converts NaN's to zeros.

ptrAt<T extends NativeType>(int i0, [int? i1, int? i2]) → Pointer<T>

equivalent to Mat::ptr<T>(i0, i1, i2)

ptrAtF16(int i0, [int? i1, int? i2]) → Float16P

region(Rect rect) → Mat

https://docs.opencv.org/4.x/d3/d63/classcv_1_1Mat.html#aa7ec97373406215f2d4bc72cc1d27036

regionAsync(Rect rect) → Future<Mat>

Available on Mat, provided by the MatAsync extension

reinterpret(MatType type) → Mat

Reset the type of matrix.

release() → void

reshape(int cn, [int rows = 0]) → Mat

Changes the shape and/or the number of channels of a 2D matrix without copying the data.

reshapeAsync(int cn, [int rows = 0]) → Future<Mat>

Available on Mat, provided by the MatAsync extension

reshapeTo(int cn, List<int> newshape) → Mat

https://docs.opencv.org/4.x/d3/d63/classcv_1_1Mat.html#ab2e41a510891e548f744832cf9b8ab89

rotate(int rotationCode, {bool inplace = false}) → Mat

rotateAsync(int rotationCode, {bool inplace = false}) → Future<Mat>

Available on Mat, provided by the MatAsync extension

row(int y) → Mat

Creates a matrix header for the specified matrix row.

rowRange(int start, int end) → Mat

Creates a matrix header for the specified row span.

rowRangeAsync(int start, int end) → Future<Mat>

Available on Mat, provided by the MatAsync extension

set<T>(int i0, int i1, T val, [int? i2]) → void

equivalent to Mat::at<T>(i0, i1, i2) = val; where T might be int, double, or cv::Vec<> like cv::Vec3b

setF32(int i0, double val, {int? i1, int? i2}) → void

setF64(int i0, double val, {int? i1, int? i2}) → void

setI16(int i0, int val, {int? i1, int? i2}) → void

setI32(int i0, int val, {int? i1, int? i2}) → void

setI8(int i0, int val, {int? i1, int? i2}) → void

setNum(int i0, int i1, num val, [int? i2]) → void

setTo(Scalar value, {Mat? mask}) → Mat

Sets all or some of the array elements to the specified value.

setU16(int i0, int val, {int? i1, int? i2}) → void

setU8(int i0, int val, {int? i1, int? i2}) → void

setVec<T extends CvVec<Struct>>(int row, int col, T val) → void

sqrt() → Mat

Calculates a square root of array elements.

sqrtAsync() → Future<Mat>

Available on Mat, provided by the MatAsync extension

Calculates a square root of array elements.

stdDev() → Scalar

Calculates standard deviation, per channel.

subtract<T>(T val, {bool inplace = false}) → Mat

subtract

subtractF32(double val, {bool inplace = false}) → Mat

subtractF64(double val, {bool inplace = false}) → Mat

subtractI16(int val, {bool inplace = false}) → Mat

subtractI32(int val, {bool inplace = false}) → Mat

subtractI8(int val, {bool inplace = false}) → Mat

subtractMat(Mat other, {bool inplace = false}) → Mat

subtractU16(int val, {bool inplace = false}) → Mat

subtractU8(int val, {bool inplace = false}) → Mat

sum() → Scalar

Sum calculates the per-channel pixel sum of an image.

sumAsync() → Future<Scalar>

Available on Mat, provided by the MatAsync extension

Sum calculates the per-channel pixel sum of an image.

t() → Mat

Transposes a matrix.

toFmtString({int fmtType = FMT_NUMPY, int f16Precision = 4, int f32Precision = 8, int f64Precision = 16, bool multiLine = true}) → String

toList({bool copy = true}) → List<List<num>>

This method converts a Mat to a 2D list.

toList3D({bool copy = true}) → List<List<List<num>>>

Returns a 3D list of the mat, only for multi-channel mats. The list is ordered as colchannels.

toString() → String

A string representation of this object.

override

transpose({bool inplace = false}) → Mat

variance() → Scalar

Similar to stdDev

Operators

operator ==(Object other) → bool

The equality operator.

inherited

Static Properties

finalizer → NativeFinalizer

final

Constants

FMT_C → const int

FMT_CSV → const int

FMT_DEFAULT → const int

FMT_MATLAB → const int

FMT_NUMPY → const int

FMT_PYTHON → const int