Class AbstractMorphology

java.lang.Object
net.algart.arrays.AbstractArrayProcessorWithContextSwitching
net.algart.matrices.morphology.AbstractMorphology
All Implemented Interfaces:
Cloneable, ArrayProcessor, ArrayProcessorWithContextSwitching, Morphology
Direct Known Subclasses:
AbstractRankMorphology, BasicMorphology

public abstract class AbstractMorphology extends AbstractArrayProcessorWithContextSwitching implements Morphology

A skeletal implementation of the Morphology interface to minimize the effort required to implement this interface.

All methods of the interface are completely implemented here via 3 following methods:

Usually the subclasses need to override only these 3 methods and isPseudoCyclic().

Author:
Daniel Alievsky
  • Constructor Details

    • AbstractMorphology

      protected AbstractMorphology(ArrayContext context)
      Creates an instance of this class with the given context.
      Parameters:
      context - the context used by this instance for all operations.
  • Method Details

    • context

      public Morphology 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 Morphology
      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: Morphology
      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 basic Morphology.dilation(Matrix, Pattern) and Morphology.erosion(Matrix, Pattern) methods as the default definition of dilation and erosion.

      This method returns true in BasicMorphology and BasicRankMorphology implementation. However, it usually returns false in ContinuedMorphology and ContinuedRankMorphology classes — excepting the only degenerated case when the used continuation mode is PSEUDO_CYCLIC.

      Specified by:
      isPseudoCyclic in interface Morphology
      Returns:
      whether this class works in the pseudo-cyclic continuation mode.
    • asDilation

      public Matrix<? extends PArray> asDilation(Matrix<? extends PArray> src, Pattern pattern)
      Description copied from interface: Morphology
      Returns an immutable view of the passed source matrix, such that any reading data from it calculates and returns the dilation of the source matrix by the specified pattern. See Morphology.dilation(Matrix, Pattern) method about the "dilation" term. The element type of the created matrix is the same as the element type of the source one.

      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 Morphology.dilation(Matrix, Pattern).

      Please note: this method does not require time (if the result is "lazy"), but the resulting matrix can work slowly! For example, reading all its content than work much slower than Morphology.dilation(Matrix, Pattern) method for 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" Morphology.dilation(Matrix, Pattern) method.

      Specified by:
      asDilation in interface Morphology
      Parameters:
      src - the source matrix.
      pattern - the pattern.
      Returns:
      the "lazy" matrix containing the dilation of the source matrix by the given pattern.
    • asErosion

      public Matrix<? extends PArray> asErosion(Matrix<? extends PArray> src, Pattern pattern)
      Description copied from interface: Morphology
      Returns an immutable view of the passed source matrix, such that any reading data from it calculates and returns the erosion of the source matrix by the specified pattern. See Morphology.erosion(Matrix, Pattern) method about the "erosion" term. The element type of the created matrix is the same as the element type of the source one.

      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 erosion; then this method will be equivalent to Morphology.erosion(Matrix, Pattern).

      Please note: this method does not require time (if the result is "lazy"), but the resulting matrix can work slowly! For example, reading all its content than work much slower than Morphology.dilation(Matrix, Pattern) method for 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" Morphology.erosion(Matrix, Pattern) method.

      Specified by:
      asErosion in interface Morphology
      Parameters:
      src - the source matrix.
      pattern - the pattern.
      Returns:
      the "lazy" matrix containing the erosion of the source matrix by the given pattern.
    • dilation

      public Matrix<? extends UpdatablePArray> dilation(Matrix<? extends PArray> src, Pattern pattern)
      Description copied from interface: Morphology
      Returns a new updatable matrix, containing the dilation of the source matrix by the specified pattern.

      Usually dilation means the elementwise maximum from the set of matrices, obtained by pseudo-cyclic shifting the source matrix by the vectors, equal to all pattern points. More precisely, let mi=Matrices.asShifted(src,ip.coordinates()), where ip is the point #i from all points contained in the pattern. Then the every element of the returned matrix is the maximum from all corresponding elements of all mi matrices. The element type of the created matrix is the same as the element type of the source one. The byte and short elements are considered to be unsigned. In a case of bit elements, the maximum is equivalent to logical OR.

      The basic morphology implementation BasicMorphology strictly complies with this definition. However, other implementations of this interface may use alternate definitions of the dilation term. For example, some percentile (90% or 80%) may be used instead of strict maximum (as in objects, returned by BasicRankMorphology.getInstance(ArrayContext, double, CustomRankPrecision) method), or elements outside the matrix may be supposed to be filled according some non-trivial rules instead of pseudo-cyclic continuation (as in ContinuedMorphology objects), or only some region of the matrix may be processed, etc.

      Please see Wikipedia to know more about the dilation.

      Specified by:
      dilation in interface Morphology
      Parameters:
      src - the source matrix.
      pattern - the pattern.
      Returns:
      the result of dilation of the source matrix by the given pattern.
      See Also:
    • erosion

      public Matrix<? extends UpdatablePArray> erosion(Matrix<? extends PArray> src, Pattern pattern)
      Description copied from interface: Morphology
      Returns a new updatable matrix, containing the erosion of the source matrix by the specified pattern.

      Usually erosion means the elementwise minimum from the set of matrices, obtained by pseudo-cyclic shifting the source matrix by the vectors, symmetric to all pattern points relatively the origin of coordinates. More precisely, let mi=Matrices.asShifted(src,ip.symmetric().coordinates()), where ip is the point #i from all points contained in the pattern. Then the every element of the returned matrix is the minimum from all corresponding elements of all mi matrices. The element type of the created matrix is the same as the element type of the source one. The byte and short elements are considered to be unsigned. In a case of bit elements, the minimum is equivalent to logical AND.

      The basic morphology implementation BasicMorphology strictly complies with this definition. However, other implementations of this interface may use alternate definitions of the erosion term. For example, some percentile (10% or 20%) may be used instead of strict minimum (as in objects, returned by BasicRankMorphology.getInstance(ArrayContext, double, CustomRankPrecision) method), or elements outside the matrix may be supposed to be filled according some non-trivial rules instead of pseudo-cyclic continuation (as in ContinuedMorphology objects), or only some region of the matrix may be processed, etc.

      Please see Wikipedia to know more about the erosion.

      Specified by:
      erosion in interface Morphology
      Parameters:
      src - the source matrix.
      pattern - the pattern.
      Returns:
      the result of erosion of the source matrix by the given pattern.
      See Also:
    • dilation

      public Matrix<? extends UpdatablePArray> dilation(Matrix<? extends PArray> src, Pattern pattern, Morphology.SubtractionMode subtractionMode)
      Description copied from interface: Morphology
      Extended version of Morphology.dilation(Matrix, Pattern) method: if subtractionMode argument is not Morphology.SubtractionMode.NONE, returns the difference between the dilation and the src matrix, according the specified mode.

      If subtractionMode==Morphology.SubtractionMode.NONE, this method is strictly equivalent to Morphology.dilation(Matrix, Pattern).

      The result of this operation with subtractionMode==Morphology.SubtractionMode.SUBTRACT_SRC_FROM_RESULT is also called the external gradient of the source matrix.

      Specified by:
      dilation in interface Morphology
      Parameters:
      src - the source matrix.
      pattern - the pattern.
      subtractionMode - whether the difference of the dilation and the source matrix should be returned.
      Returns:
      the result of dilation of the source matrix by the given pattern or the difference of the dilation and the source matrix.
    • erosion

      public Matrix<? extends UpdatablePArray> erosion(Matrix<? extends PArray> src, Pattern pattern, Morphology.SubtractionMode subtractionMode)
      Description copied from interface: Morphology
      Extended version of Morphology.erosion(Matrix, Pattern) method: if subtractionMode argument is not Morphology.SubtractionMode.NONE, returns the difference between the erosion and the src matrix, according the specified mode.

      If subtractionMode==Morphology.SubtractionMode.NONE, this method is strictly equivalent to Morphology.erosion(Matrix, Pattern).

      The result of this operation with subtractionMode==Morphology.SubtractionMode.SUBTRACT_RESULT_FROM_SRC is also called the internal gradient of the source matrix.

      Specified by:
      erosion in interface Morphology
      Parameters:
      src - the source matrix.
      pattern - the pattern.
      subtractionMode - whether the difference of the erosion and the source matrix should be returned.
      Returns:
      the result of erosion of the source matrix by the given pattern or the difference of the erosion and the source matrix.
    • dilation

      public void dilation(Matrix<? extends UpdatablePArray> dest, Matrix<? extends PArray> src, Pattern pattern, boolean disableMemoryAllocation)
      Description copied from interface: Morphology
      Equivalent to Morphology.dilation(Matrix, Pattern) method, but the result matrix will be placed in the dest argument. It allows to avoid extra memory allocation if you need to perform dilation many times from one matrix to another.

      Moreover, if disableMemoryAllocation argument is true, this method guarantees that no any additional memory will be allocated, even if it can optimize the algorithm speed. In this case, this method is always executed in one pass: it is equivalent to creating new lazy matrix by Morphology.asDilation(Matrix src, Pattern pattern) method and further copying it into dest by Matrices.copy(ArrayContext, Matrix, Matrix) method. It can be useful if you are sure that the pattern is small enough (usually 2-10 points), and allocation additional work matrices can slow down the algorithm to greater extent than using the simple one-pass algorithm.

      If the element type of the dest matrix is not the same as the source element type (dest.elementType()!=src.elementType()), the elements are automatically cast to the necessary type. More precisely, in this case the dest matrix, before all further calculations, is replaced with

       Matrices.asUpdatableFuncMatrix(true, Func.UPDATABLE_IDENTITY, src.updatableType(UpdatablePArray.class), dest)
       

      We do not recommend to pass matrices with different element types: it can slow down calculations.

      Specified by:
      dilation in interface Morphology
      Parameters:
      dest - the target matrix.
      src - the source matrix.
      pattern - the pattern.
      disableMemoryAllocation - if false, this method may allocate additional temporary matrices for optimizing the algorithm speed; if true, no any work memory will be allocated.
    • erosion

      public void erosion(Matrix<? extends UpdatablePArray> dest, Matrix<? extends PArray> src, Pattern pattern, boolean disableMemoryAllocation)
      Description copied from interface: Morphology
      Equivalent to Morphology.erosion(Matrix, Pattern) method, but the result matrix will be placed in the dest argument. It allows to avoid extra memory allocation if you need to perform erosion many times from one matrix to another.

      Moreover, if disableMemoryAllocation argument is true, this method guarantees that no any additional memory will be allocated, even if it can optimize the algorithm speed. In this case, this method is always executed in one pass: it is equivalent to creating new lazy matrix by Morphology.asDilation(Matrix src, Pattern pattern) method and further copying it into dest by Matrices.copy(ArrayContext, Matrix, Matrix) method. It can be useful if you are sure that the pattern is small enough (usually 2-10 points), and allocation additional work matrices can slow down the algorithm to greater extent than using the simple one-pass algorithm.

      If the element type of the dest matrix is not the same as the source element type (dest.elementType()!=src.elementType()), the elements are automatically cast to the necessary type. More precisely, in this case the dest matrix, before all further calculations, is replaced with

       Matrices.asUpdatableFuncMatrix(true, Func.UPDATABLE_IDENTITY, src.updatableType(UpdatablePArray.class), dest)
       

      We do not recommend to pass matrices with different element types: it can slow down calculations.

      Specified by:
      erosion in interface Morphology
      Parameters:
      dest - the target matrix.
      src - the source matrix.
      pattern - the pattern.
      disableMemoryAllocation - if false, this method may allocate additional temporary matrices for optimizing the algorithm speed; if true, no any work memory will be allocated.
    • dilation

      public void dilation(Matrix<? extends UpdatablePArray> dest, Matrix<? extends PArray> src, Pattern pattern)
      Description copied from interface: Morphology
      Specified by:
      dilation in interface Morphology
      Parameters:
      dest - the target matrix.
      src - the source matrix.
      pattern - the pattern.
    • erosion

      public void erosion(Matrix<? extends UpdatablePArray> dest, Matrix<? extends PArray> src, Pattern pattern)
      Description copied from interface: Morphology
      Specified by:
      erosion in interface Morphology
      Parameters:
      dest - the target matrix.
      src - the source matrix.
      pattern - the pattern.
    • dilationErosion

      public Matrix<? extends UpdatablePArray> dilationErosion(Matrix<? extends PArray> src, Pattern dilationPattern, Pattern erosionPattern, Morphology.SubtractionMode subtractionMode)
      Description copied from interface: Morphology
      Returns a new updatable matrix, containing the result of sequential dilation(src, dilationPattern) and erosion(src, erosionPattern) of the source matrix by the specified patterns.

      If subtractionMode is not Morphology.SubtractionMode.NONE, the behaviour is little other: this method returns the difference between the result of these two operation and the src matrix, according the specified mode.

      When both patterns are equal, the result is the closing of the matrix.

      Specified by:
      dilationErosion in interface Morphology
      Parameters:
      src - the source matrix.
      dilationPattern - the pattern for dilation.
      erosionPattern - the pattern for erosion.
      subtractionMode - whether the difference with the source matrix should be returned.
      Returns:
      the result of sequential dilation and erosion of the source matrix by the given patterns or the difference of such result and the source matrix.
    • erosionDilation

      public Matrix<? extends UpdatablePArray> erosionDilation(Matrix<? extends PArray> src, Pattern erosionPattern, Pattern dilationPattern, Morphology.SubtractionMode subtractionMode)
      Description copied from interface: Morphology
      Returns a new updatable matrix, containing the result of sequential erosion(src, erosionPattern) and dilation(src, dilationPattern) of the source matrix by the specified patterns.

      If subtractionMode is not Morphology.SubtractionMode.NONE, the behaviour is little other: this method returns the difference between the result of these two operation and the src matrix, according the specified mode.

      When both patterns are equal, the result is the opening of the matrix.

      Specified by:
      erosionDilation in interface Morphology
      Parameters:
      src - the source matrix.
      erosionPattern - the pattern for erosion.
      dilationPattern - the pattern for dilation.
      subtractionMode - whether the difference with the source matrix should be returned.
      Returns:
      the result of sequential erosion and dilation of the source matrix by the given patterns or the difference of such result and the source matrix.
    • closing

      public Matrix<? extends UpdatablePArray> closing(Matrix<? extends PArray> src, Pattern pattern, Morphology.SubtractionMode subtractionMode)
      Description copied from interface: Morphology
      Returns a new updatable matrix, containing the closing of the source matrix by the specified pattern.

      Closing means the result of sequential performing dilation and erosion of the source matrix with the same pattern.

      If subtractionMode is not Morphology.SubtractionMode.NONE, the behaviour is little other: this method returns the difference between the closing and the src matrix, according the specified mode. For example, Morphology.SubtractionMode.SUBTRACT_SRC_FROM_RESULT argument with this method allows to remove "light" background from a gray-scale image, represented by src matrix.

      This method is equivalent to dilationErosion(src, pattern, pattern, subtractionMode).

      Please see Wikipedia to know more about the closing.

      Specified by:
      closing in interface Morphology
      Parameters:
      src - the source matrix.
      pattern - the pattern.
      subtractionMode - whether the difference of the closing and the source matrix should be returned.
      Returns:
      the result of closing of the source matrix by the given pattern or the difference of the closing and the source matrix.
    • opening

      public Matrix<? extends UpdatablePArray> opening(Matrix<? extends PArray> src, Pattern pattern, Morphology.SubtractionMode subtractionMode)
      Description copied from interface: Morphology
      Returns a new updatable matrix, containing the opening of the source matrix by the specified pattern.

      Opening means the result of sequential performing erosion and dilation of the source matrix with the same pattern.

      If subtractionMode is not Morphology.SubtractionMode.NONE, the behaviour is little other: this method returns the difference between the opening and the src matrix, according the specified mode. For example, Morphology.SubtractionMode.SUBTRACT_RESULT_FROM_SRC argument with this method allows to remove "dark" background from a gray-scale image, represented by src matrix.

      This method is equivalent to erosionDilation(src, pattern, pattern, subtractionMode).

      Please see Wikipedia to know more about the opening.

      Specified by:
      opening in interface Morphology
      Parameters:
      src - the source matrix.
      pattern - the pattern.
      subtractionMode - whether the difference of the opening and the source matrix should be returned.
      Returns:
      the result of opening of the source matrix by the given pattern or the difference of the opening and the source matrix.
    • weakDilation

      public Matrix<? extends UpdatablePArray> weakDilation(Matrix<? extends PArray> src, Pattern pattern)
      Description copied from interface: Morphology
      Returns a new updatable matrix, containing the weak dilation of the source matrix by the specified pattern.

      Weak dilation of the matrix A is defined as an elementwise difference B=dilation(A)-(closing(A)-A). It is obvious that, for any elements, A<=B<=dilation(A) (because both differences dilation(A)-closing(A) and closing(A)-A are non-negative).

      (In this method, the closing is supposed to be performed with the last argument Morphology.SubtractionMode.NONE.)

      Specified by:
      weakDilation in interface Morphology
      Parameters:
      src - the source matrix.
      pattern - the pattern.
      Returns:
      the result of weak dilation of the source matrix by the given pattern.
    • weakErosion

      public Matrix<? extends UpdatablePArray> weakErosion(Matrix<? extends PArray> src, Pattern pattern)
      Description copied from interface: Morphology
      Returns a new updatable matrix, containing the weak erosion of the source matrix by the specified pattern.

      Weak erosion of the matrix A is defined as an elementwise sum B=erosion(A)+(A-opening(A)). It is obvious that, for any elements, A>=B>=erosion(A) (because both differences opening(A)-erosion(A) and A-opening(A) are non-negative).

      (In this method, the opening is supposed to be performed with the last argument Morphology.SubtractionMode.NONE.)

      Specified by:
      weakErosion in interface Morphology
      Parameters:
      src - the source matrix.
      pattern - the pattern.
      Returns:
      the result of weak dilation of the source matrix by the given pattern.
    • maskedDilationErosion

      public Matrix<? extends UpdatablePArray> maskedDilationErosion(Matrix<? extends PArray> src, Pattern dilationPattern, Pattern erosionPattern)
      Description copied from interface: Morphology
      Returns the elementwise minimum between the source matrix and the result of dilationErosion(src, dilationPattern, erosionPattern, Morphology.SubtractionMode.NONE) call.

      Let B is the result of this method, A is the source matrix, Q is dilationPattern, P is erosionPattern:
      B=min(A,erosion(dilation(A,Q),P))
      for any elements. It is obvious that (for any elements) A>=B>=erosion(A,P). But if Q is a some "boundary" or "carcass" of the erosion pattern P, then a stronger condition is true: A>=B>=opening(A,P).

      More precisely, there is the following theorem.

      If Q is a subset of P and the Minkowski sum P⊕Q is equal to P⊕P (see Pattern.carcass() method), then B>=opening(A,P).

      Below is the proof for the binary case. (For other element types, it's enough to consider the system of binary matrices A>=threshold for all possible real values threshold.)

      Let some point xopening(A,P). It means: there is such p1∈P, that for all p∈P we have x+p1-p∈A (the statement A). We already know, that x∈A (the case p=p1), and we also need to prove, that xerosion(dilation(A,Q),P).

      Let's suppose that it is not true. It means: there is such p2∈P, that for all q∈Q we have x+p2-q∉A (the statement B)

      Let x will be the origin of coordinates: x=0. Then, let P1=-P+p1={p1-p, p∈P}. Note: the origin 0∈P1 (the case p=p1). We have P1⊂A (statement A), so, for all q∈Q we have p2-q∉P1 (because p2-q∉A, statement B). In other words, p2∉P1⊕Q (dilation of P by Q, or Minkowski sum of P and Q). On the other hand, it's obvious that p2∈P1⊕P, because 0∈P1 and, so, P⊂P⊕P1=P1⊕P.

      There is a contradiction: according to the condition, there must be P1⊕P=P1⊕Q. The theorem is proved.

      This fact allows to interpret this method, if dilationPattern is a "boundary" of erosionPattern (usually UniformGridPattern.surface() or a similar point set), as a "weak" analog of opening. For binary images, it helps to remove small isolated objects, but (unlike usual opening) to preserve thin structures.

      Specified by:
      maskedDilationErosion in interface Morphology
      Parameters:
      src - the source matrix.
      dilationPattern - the pattern for dilation.
      erosionPattern - the pattern for erosion.
      Returns:
      the elementwise minimum between the source matrix and its sequential dilation and erosion by the given patterns.
    • maskedErosionDilation

      public Matrix<? extends UpdatablePArray> maskedErosionDilation(Matrix<? extends PArray> src, Pattern erosionPattern, Pattern dilationPattern)
      Description copied from interface: Morphology
      Returns the elementwise maximum between the source matrix and the result of erosionDilation(src, erosionPattern, dilationPattern, Morphology.SubtractionMode.NONE) call.

      This is an inverse method for Morphology.maskedDilationErosion(Matrix, Pattern, Pattern).

      Specified by:
      maskedErosionDilation in interface Morphology
      Parameters:
      src - the source matrix.
      erosionPattern - the pattern for erosion.
      dilationPattern - the pattern for dilation.
      Returns:
      the elementwise maximum between the source matrix and its sequential erosion and dilation by the given patterns.
    • beucherGradient

      public Matrix<? extends UpdatablePArray> beucherGradient(Matrix<? extends PArray> src, Pattern pattern)
      Description copied from interface: Morphology
      Returns a new updatable matrix, containing the Beucher gradient of the source matrix by the specified pattern, that means the elementwise difference between dilation and erosion of the source matrix with the same pattern.

      More precisely, the Beucher gradient of the matrix A is defined as an elementwise positive difference B=max(0,dilation(A)-erosion(A)).

      The element type of the created matrix is the same as the element type of the source one. The byte and short elements are considered to be unsigned.

      Specified by:
      beucherGradient in interface Morphology
      Parameters:
      src - the source matrix.
      pattern - the pattern.
      Returns:
      the Beucher gradient of the source matrix by the given pattern.
    • asDilationOrErosion

      protected abstract Matrix<? extends PArray> asDilationOrErosion(Matrix<? extends PArray> src, Pattern pattern, boolean isDilation)
      This method must be equivalent to asDilation(Matrix src, Pattern pattern) if isDilation argument is true or to asErosion(Matrix src, Pattern pattern) if isDilation argument is false.

      The implementations of those methods, provided by this class, just call this method with corresponding isDilation argument.

      Parameters:
      src - the source matrix.
      pattern - the pattern.
      isDilation - what should return this method: dilation or erosion.
      Returns:
      the "lazy" matrix containing the dilation or erosion of the source matrix.
      Throws:
      NullPointerException - if one of the arguments is null.
      IllegalArgumentException - if the number of the pattern dimensions pattern.dimCount() is not equal to src.dimCount().
    • dilationOrErosion

      protected Matrix<? extends UpdatablePArray> dilationOrErosion(Matrix<? extends UpdatablePArray> dest, Matrix<? extends PArray> src, Pattern pattern, boolean isDilation, boolean disableMemoryAllocation)
      This method must be equivalent to dilation(Matrix dest, Matrix src, Pattern pattern, boolean disableMemoryAllocation) if isDilation argument is true or to erosion(Matrix dest, Matrix src, Pattern pattern, boolean disableMemoryAllocation) if isDilation argument is false. There is the only little difference: if dest argument is null, this methods does not throw NullPointerException, but allocates new matrix with the same dimensions and element type as src and use it for storing the result. The result (newly created matrix or non-null dest argument) is returned as the result of this method.

      The implementations of dilation(Matrix dest, Pattern pattern), erosion(Matrix dest, Pattern pattern), dilation(Matrix dest, Matrix src, Pattern pattern, boolean disableMemoryAllocation), erosion(Matrix dest, Matrix src, Pattern pattern, boolean disableMemoryAllocation) methods, provided by this class, just call this method with corresponding isDilation argument and with dest==null in a case of first two methods.

      The implementation of this method, provided by AbstractMorphology class, just copies the result of asDilationOrErosion(Matrix, Pattern, boolean) asDilationOrErosion} method to dest matrix:

       Matrices.copy(context, castDest, asDilationOrErosion(Matrix, Pattern, boolean)
       asDilationOrErosion}(src, pattern, isDilation));

      where castDest is dest if dest.elementType()==src.elementType(), the newly created matrix if dest==null or the dest matrix, cast to the necessary element type, if the source and destination element types are different:

       Matrices.asUpdatableFuncMatrix(true, Func.UPDATABLE_IDENTITY, src.updatableType(UpdatablePArray.class), dest)
       

      The implementations of this method in the inheritors usually provide better algorithms, especially if disableMemoryAllocation argument is false.

      Parameters:
      dest - the target matrix (or null for creating a new matrix).
      src - the source matrix.
      pattern - the pattern.
      isDilation - what should perform this method: dilation or erosion.
      disableMemoryAllocation - if false, this method may allocate additional temporary matrices for optimizing the algorithm speed; if true, no any work memory will be allocated.
      Returns:
      the reference to dest argument if it is not null, newly allocated resulting matrix in other case.
      Throws:
      NullPointerException - if src or pattern argument is null.
      SizeMismatchException - if dest!=null and the passed matrices have different dimensions.
      IllegalArgumentException - if the number of the pattern dimensions pattern.dimCount() is not equal to src.dimCount().
    • dimensionsAllowed

      protected boolean dimensionsAllowed(Matrix<? extends PArray> matrix, Pattern pattern)