Package net.algart.matrices.linearfiltering

Class AbstractConvolution

java.lang.Object

net.algart.arrays.AbstractArrayProcessorWithContextSwitching

net.algart.matrices.linearfiltering.AbstractConvolution

All Implemented Interfaces:

Cloneable, ArrayProcessor, ArrayProcessorWithContextSwitching, Convolution

Direct Known Subclasses:

BasicConvolution

public abstract class AbstractConvolution
extends AbstractArrayProcessorWithContextSwitching
implements Convolution

Field Summary

Fields

Modifier and Type	Field	Description
protected final boolean	incrementByHalfForInteger
protected final boolean	incrementForUnsigned

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	AbstractConvolution(ArrayContext context, boolean incrementForUnsigned, boolean incrementByHalfForInteger)	Creates an instance of this class with the given context.

Method Summary

Modifier and Type	Method	Description
abstract <T extends PArray> Matrix<T>	asConvolution(Class<? extends T> requiredType, Matrix<? extends PArray> src, WeightedPattern pattern)	Returns an immutable view of the passed source matrix, such that any reading data from it calculates and returns the convolution of the source matrix by the specified pattern.
Matrix<? extends PArray>	asConvolution(Matrix<? extends PArray> src, WeightedPattern pattern)	Equivalent to asConvolution(src.type(PArray.class), src, pattern).
Convolution	context(ArrayContext newContext)	This method is implemented here via cloning this object (by standard clone() call) and replacing the value of the field, where a reference to the current context is stored, with newContext value.
<T extends PArray> Matrix<? extends T>	convolution(Class<? extends T> requiredType, Matrix<? extends PArray> src, WeightedPattern pattern)
Matrix<? extends UpdatablePArray>	convolution(Matrix<? extends PArray> src, WeightedPattern pattern)	This implementation just creates a lazy convolution via asConvolution(Class, Matrix, WeightedPattern) method and copies it into a newly created matrix via Matrices.copy(ArrayContext, Matrix, Matrix) method.
void	convolution(Matrix<? extends UpdatablePArray> dest, Matrix<? extends PArray> src, WeightedPattern pattern)
double	increment(Class<?> elementType)
abstract boolean	isPseudoCyclic()	Returns true, if this class works in the default pseudo-cyclic continuation mode.

Methods inherited from class net.algart.arrays.AbstractArrayProcessorWithContextSwitching

context, contextPart, memoryModel

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface net.algart.arrays.ArrayProcessor

context

Field Details

incrementForUnsigned

protected final boolean incrementForUnsigned

incrementByHalfForInteger

protected final boolean incrementByHalfForInteger

Constructor Details

AbstractConvolution

protected AbstractConvolution(ArrayContext context,
 boolean incrementForUnsigned,
 boolean incrementByHalfForInteger)

Creates an instance of this class with the given context.

Parameters:

context - the context used by this instance for all operations.

incrementForUnsigned - if true, when the type of the convolution result is an unsigned number in terms of AlgART libraries — byte, short, char — it is automatically incremented by 128 (byte) or 32768 (short and char).

incrementByHalfForInteger - if true, when the type of the convolution result is integer, the precise result is automatically increments by 0.5 before casting.

Method Details

context

public Convolution context(ArrayContext newContext)

Description copied from class: AbstractArrayProcessorWithContextSwitching

This method is implemented here via cloning this object (by standard clone() call) and replacing the value of the field, where a reference to the current context is stored, with newContext value. This technique is suitable for most implementation. However, if you need, you can override this method; maybe, it is enough to override clone() instead.

Specified by:

context in interface ArrayProcessorWithContextSwitching

Specified by:

context in interface Convolution

Overrides:

context in class AbstractArrayProcessorWithContextSwitching

Parameters:

newContext - another context, used by the returned instance; may be null.

Returns:

new instance with another context.

isPseudoCyclic

public abstract boolean isPseudoCyclic()

Description copied from interface: Convolution

Returns true, if this class works in the default pseudo-cyclic continuation mode.

More precisely, it means that when the value in some element of the processed matrix, returned by a method of this class, depends on elements of the source matrix, lying outside its bounds, then it is supposed that the values outside the source matrix are calculated as described in Matrix.ContinuationMode.PSEUDO_CYCLIC. Exactly such behaviour is specified in the comments to the Convolution.convolution(Matrix, WeightedPattern) method as the default definition of convolution.

This method returns true in BasicConvolution implementation. However, it usually returns false in ContinuedConvolution class — excepting the only degenerated case when the used continuation mode is PSEUDO_CYCLIC.

Specified by:

isPseudoCyclic in interface Convolution

Returns:

whether this class works in the pseudo-cyclic continuation mode.

increment

public double increment(Class<?> elementType)

Specified by:

increment in interface Convolution

asConvolution

public Matrix<? extends PArray> asConvolution(Matrix<? extends PArray> src,
 WeightedPattern pattern)

Description copied from interface: Convolution

Equivalent to asConvolution(src.type(PArray.class), src, pattern). In other words, the element type of the returned matrix is chosen the same as in src matrix.

Specified by:

asConvolution in interface Convolution

Parameters:

src - the source matrix.

pattern - the pattern.

Returns:

the "lazy" matrix containing the convolution of the source matrix with the given pattern.

asConvolution

public abstract <T extends PArray> Matrix<T> asConvolution(Class<? extends T> requiredType,
 Matrix<? extends PArray> src,
 WeightedPattern pattern)

Description copied from interface: Convolution

Returns an immutable view of the passed source matrix, such that any reading data from it calculates and returns the convolution of the source matrix by the specified pattern. See Convolution.convolution(Class, Matrix, WeightedPattern) method about the "convolution" term.

The matrix, returned by this method, is immutable, and the class of its built-in array implements one of the basic interfaces BitArray, CharArray, ByteArray, ShortArray, IntArray, LongArray, FloatArray or DoubleArray. The class of desired interface (one of 8 possible classes) must be passed as requiredType argument. So, it defines the element type of the returned matrix. For example, if requiredType=ByteArray.class, the returned matrix consists of byte elements. The rules of casting the real numbers, results of the convolution, to the desired element type are the same as in Arrays.asFuncArray(boolean, net.algart.math.functions.Func, Class, PArray...) method with the argument truncateOverflows=true.

The result is usually "lazy", that means that this method finishes immediately and all actual calculations are performed while getting elements of the returned matrix. It is true for all implementations provided by this package. However, some implementations may not support lazy dilation; then this method will be equivalent to Convolution.convolution(Class, Matrix, WeightedPattern).

Please note: this method does not require time, but the resulting matrix can work slowly! for example, reading all its content than work much slower than Convolution.convolution(Class, Matrix, WeightedPattern) method for some complex patterns. Usually you should use it only for very little patterns, or if you know that the implementation of this interface does not provide better algorithm for non-"lazy" Convolution.convolution(Class, Matrix, WeightedPattern) method.

Specified by:

asConvolution in interface Convolution

Parameters:

requiredType - desired type of the built-in array in the returned matrix.

src - the source matrix.

pattern - the pattern.

Returns:

the "lazy" matrix containing the convolution of the source matrix with the given pattern.

convolution

public Matrix<? extends UpdatablePArray> convolution(Matrix<? extends PArray> src,
 WeightedPattern pattern)

This implementation just creates a lazy convolution via asConvolution(Class, Matrix, WeightedPattern) method and copies it into a newly created matrix via Matrices.copy(ArrayContext, Matrix, Matrix) method. This method should be usually overridden to provide better implementations.

Specified by:

convolution in interface Convolution

Parameters:

src - the source matrix.

pattern - the pattern.

Returns:

the result of convolution of the source matrix with the given pattern.

Throws:

NullPointerException - if one of the arguments is null.

See Also:

• asConvolution(Class, Matrix, WeightedPattern)

convolution

public <T extends PArray> Matrix<? extends T> convolution(Class<? extends T> requiredType,
 Matrix<? extends PArray> src,
 WeightedPattern pattern)

Specified by:

convolution in interface Convolution

convolution

public void convolution(Matrix<? extends UpdatablePArray> dest,
 Matrix<? extends PArray> src,
 WeightedPattern pattern)

Specified by:

convolution in interface Convolution