Package org.geotools.referencing.operation.transform

Class WarpTransform2D

Object
Formattable
AbstractMathTransform
WarpTransform2D
All Implemented Interfaces:
Serializable, MathTransform, MathTransform2D
public class WarpTransform2D extends AbstractMathTransform implements MathTransform2D, Serializable
Wraps an arbitrary Warp object as a two-dimensional transform. Calls to transform methods are forwarded to the warpPoint method, or something equivalent. This implies that source coordinates may be rounded to nearest integers before the transformation is applied.

This transform is typically used with grid coverage "Resample" operation for reprojecting an image. Source and destination coordinates are usually pixel coordinates in source and target image, which is why this transform may use integer arithmetic.

This math transform can be created alone (by invoking its public constructors directly), or it can be created by a factory like LocalizationGrid.

For more information on image warp, see Geometric Image Manipulation in the Programming in Java Advanced Imaging guide.

Since:
2.1
Author:
Martin Desruisseaux, Alessio Fabiani
See Also:
  • LocalizationGrid#getPolynomialTransform(int)
  • Warp
  • WarpOpImage
  • WarpDescriptor
  • Serialized Form

  • Field Details

    • MAX_DEGREE

      public static final int MAX_DEGREE
      The maximal polynomial degree allowed.
      Since:
      2.4
      See Also:

  • Constructor Details

    • WarpTransform2D

      public WarpTransform2D(Point2D[] srcCoords, Point2D[] dstCoords, int degree)
      Constructs a warp transform that approximatively maps the given source coordinates to the given destination coordinates. The transformation is performed using some polynomial warp with the degree supplied in argument. The number of points required for each degree of warp are as follows:

      Degree of WarpNumber of Points
      13
      26
      310
      415
      521
      628
      736
      Parameters:
      srcCoords - Source coordinates.
      dstCoords - Desination coordinates.
      degree - The desired degree of the warp polynomials.

    • WarpTransform2D

      public WarpTransform2D(Rectangle2D srcBounds, Point2D[] srcCoords, int srcOffset, Rectangle2D dstBounds, Point2D[] dstCoords, int dstOffset, int numCoords, int degree)
      Constructs a warp transform that approximatively maps the given source coordinates to the given destination coordinates. The transformation is performed using some polynomial warp with the degree supplied in argument.
      Parameters:
      srcBounds - Bounding box of source coordinates, or null if unknow.
      srcCoords - Source coordinates.
      srcOffset - The inital entry of srcCoords to be used.
      dstBounds - Bounding box of destination coordinates, or null if unknow.
      dstCoords - Destination coordinates.
      dstOffset - The inital entry of dstCoords to be used.
      numCoords - The number of coordinates from srcCoords and dstCoords to be used.
      degree - The desired degree of the warp polynomials.

    • WarpTransform2D

      public WarpTransform2D(Rectangle2D srcBounds, float[] srcCoords, int srcOffset, Rectangle2D dstBounds, float[] dstCoords, int dstOffset, int numCoords, int degree)
      Constructs a warp transform that approximatively maps the given source coordinates to the given destination coordinates. The transformation is performed using some polynomial warp with the degree supplied in argument.
      Parameters:
      srcBounds - Bounding box of source coordinates, or null if unknow.
      srcCoords - Source coordinates with x and y alternating.
      srcOffset - The inital entry of srcCoords to be used.
      dstBounds - Bounding box of destination coordinates, or null if unknow.
      dstCoords - Destination coordinates with x and y alternating.
      dstOffset - The inital entry of dstCoords to be used.
      numCoords - The number of coordinates from srcCoords and dstCoords to be used.
      degree - The desired degree of the warp polynomials.

    • WarpTransform2D

      protected WarpTransform2D(Warp warp, Warp inverse)
      Constructs a transform using the specified warp object. Transformations will be applied using the warpPoint method or something equivalent.
      Parameters:
      warp - The image warp to wrap into a math transform.
      inverse - An image warp to uses for the inverse transform, or null in none.

  • Method Details

    • create

      public static MathTransform2D create(Warp warp)
      Returns a transform using the specified warp object. Transformations will be applied using the warpPoint method or something equivalent.
      Parameters:
      warp - The image warp to wrap into a math transform.
      Returns:
      The transform for the given warp.

    • getWarp

      public static Warp getWarp(CharSequence name, MathTransform2D transform)
      Returns a image warp for the specified transform. The Warp.warpPoint method transforms coordinates from source to target CRS. Note that JAI's warp operation needs a warp object with the opposite semantic (i.e. the image warp must transforms coordinates from target to source CRS). Consequently, consider invoking getWarp(transform.inverse()) if the warp object is going to be used in an image reprojection.
      Parameters:
      name - The image or coverage name, or null in unknow. Used only for formatting error message if some TransformException are thrown by the supplied transform.
      transform - The transform to returns as an image warp.
      Returns:
      The warp for the given transform.

    • getWarp

      public Warp getWarp()
      Returns image warp wrapped by this transform. The Warp.warpPoint method transforms coordinates from source to target CRS. Note that JAI's warp operation needs a warp object with the opposite semantic (i.e. the image warp must transforms coordinates from target to source CRS). Consequently, consider invoking inverse.getWarp() if the warp object is going to be used in an image reprojection.

    • getParameterDescriptors

      public ParameterDescriptorGroup getParameterDescriptors()
      Returns the parameter descriptors for this math transform.
      Overrides:
      getParameterDescriptors in class AbstractMathTransform
      Returns:
      The parameter descriptors for this math transform, or null.
      See Also:

    • getParameterValues

      public ParameterValueGroup getParameterValues()
      Returns the parameter values for this math transform.
      Overrides:
      getParameterValues in class AbstractMathTransform
      Returns:
      A copy of the parameter values for this math transform, or null.
      See Also:

    • getSourceDimensions

      public int getSourceDimensions()
      Returns the dimension of input points.
      Specified by:
      getSourceDimensions in interface MathTransform
      Specified by:
      getSourceDimensions in class AbstractMathTransform
      Returns:
      The dimension of input points.

    • getTargetDimensions

      public int getTargetDimensions()
      Returns the dimension of output points.
      Specified by:
      getTargetDimensions in interface MathTransform
      Specified by:
      getTargetDimensions in class AbstractMathTransform
      Returns:
      The dimension of output points.

    • isIdentity

      public boolean isIdentity()
      Tests if this transform is the identity transform.
      Specified by:
      isIdentity in interface MathTransform
      Overrides:
      isIdentity in class AbstractMathTransform
      Returns:
      true if this MathTransform is an identity transform; false otherwise.

    • transform

      public Point2D transform(Point2D ptSrc, Point2D ptDst)
      Transforms source coordinates (usually pixel indices) into destination coordinates (usually "real world" coordinates).
      Specified by:
      transform in interface MathTransform2D
      Overrides:
      transform in class AbstractMathTransform
      Parameters:
      ptSrc - the specified coordinate point to be transformed.
      ptDst - the specified coordinate point that stores the result of transforming ptSrc, or null.
      Returns:
      the coordinate point after transforming ptSrc and storing the result in ptDst.
      See Also:

    • transform

      public void transform(float[] srcPts, int srcOff, float[] dstPts, int dstOff, int numPts)
      Transforms source coordinates (usually pixel indices) into destination coordinates (usually "real world" coordinates).
      Specified by:
      transform in interface MathTransform
      Overrides:
      transform in class AbstractMathTransform
      Parameters:
      srcPts - the array containing the source point coordinates.
      srcOff - the offset to the first point to be transformed in the source array.
      dstPts - the array into which the transformed point coordinates are returned. May be the same than srcPts.
      dstOff - the offset to the location of the first transformed point that is stored in the destination array.
      numPts - the number of point objects to be transformed.

    • transform

      public void transform(double[] srcPts, int srcOff, double[] dstPts, int dstOff, int numPts)
      Transforms source coordinates (usually pixel indices) into destination coordinates (usually "real world" coordinates).
      Specified by:
      transform in interface MathTransform
      Parameters:
      srcPts - the array containing the source point coordinates.
      srcOff - the offset to the first point to be transformed in the source array.
      dstPts - the array into which the transformed point coordinates are returned. May be the same than srcPts.
      dstOff - the offset to the location of the first transformed point that is stored in the destination array.
      numPts - the number of point objects to be transformed.

    • inverse

      public MathTransform2D inverse() throws NoninvertibleTransformException
      Returns the inverse transform.
      Specified by:
      inverse in interface MathTransform
      Specified by:
      inverse in interface MathTransform2D
      Overrides:
      inverse in class AbstractMathTransform
      Returns:
      The inverse transform.
      Throws:
      NoninvertibleTransformException - if no inverse warp were specified at construction time.

    • hashCode

      public int hashCode()
      Returns a hash value for this transform.
      Overrides:
      hashCode in class AbstractMathTransform

    • equals

      public boolean equals(Object object)
      Compares this transform with the specified object for equality.
      Overrides:
      equals in class AbstractMathTransform
      Parameters:
      object - The object to compare with this transform.
      Returns:
      true if the given object is a transform of the same class and if, given identical source position, the transformed position would be the equals.