Package paletai.mapping

Class Homography

java.lang.Object
paletai.mapping.Homography
public class Homography extends Object
A class for applying homography transformations to points. Wraps the mathematical operations from MathHomography with convenient point transformation methods.

This class maintains both a homography matrix and its inverse, allowing efficient forward and backward transformations between coordinate systems.

Key features:

  • Forward and inverse homography transformations
  • Automatic inverse matrix calculation
  • Matrix state management
  • Integration with Processing's PVector system
See Also:

  • Constructor Summary

    Constructors
    Constructor
    Description
    Homography()
    Constructs a Homography object initialized with identity matrices.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    updateHomographyMatrix(float[][] h)
    Updates the homography matrix and automatically calculates its inverse.
    processing.core.PVector
    vectorInvertTransform(processing.core.PVector in)
    Transforms a point using the inverse homography matrix (backward transformation).
    processing.core.PVector
    vectorTransform(processing.core.PVector in)
    Transforms a point using the homography matrix (forward transformation).

    Methods inherited from class java.lang.Object

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

  • Constructor Details

    • Homography

      public Homography()
      Constructs a Homography object initialized with identity matrices. Creates both the homography matrix and its inverse as identity matrices, resulting in no transformation when applied.
      See Also:

  • Method Details

    • updateHomographyMatrix

      public void updateHomographyMatrix(float[][] h)
      Updates the homography matrix and automatically calculates its inverse. Maintains both matrices for efficient forward and backward transformations.
      Parameters:
      h - The new 3x3 homography matrix to use
      See Also:

    • vectorTransform

      public processing.core.PVector vectorTransform(processing.core.PVector in)
      Transforms a point using the homography matrix (forward transformation). Applies the perspective transformation: out = H * in. Transforms from source coordinates to destination coordinates.
      Parameters:
      in - The input point to transform
      Returns:
      The transformed point in destination coordinates

    • vectorInvertTransform

      public processing.core.PVector vectorInvertTransform(processing.core.PVector in)
      Transforms a point using the inverse homography matrix (backward transformation). Applies the inverse perspective transformation: out = inv(H) * in. Transforms from destination coordinates back to source coordinates. This is useful for mapping points from the output space back to the original input space.
      Parameters:
      in - The input point to inverse-transform (in destination coordinates)
      Returns:
      The inverse-transformed point in source coordinates