DitherUtil (Apache FOP Core 2.11 API)
Date: 2025-04-24

org.apache.fop.util.bitmap

## Class DitherUtil

- java.lang.Object
- - org.apache.fop.util.bitmap.DitherUtil

-     public final class DitherUtil
      extends Object

  Utility methods for dithering.

- - ### Field Summary

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `static int` | `DITHER_MATRIX_2X2` Selects a 2x2 Bayer dither matrix (5 grayscales)
    `static int` | `DITHER_MATRIX_4X4` Selects a 4x4 Bayer dither matrix (17 grayscales)
    `static int` | `DITHER_MATRIX_8X8` Selects a 8x8 Bayer dither matrix (65 grayscales)

  - ### Method Summary

    All Methods Static Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `static int[]` | `getBayerBasePattern(int matrix)` Returns the Bayer dither base pattern for a particular matrix size.
    `static byte[]` | `getBayerDither(int matrix, Color col, boolean doubleMatrix)` Returns a byte array containing the dither pattern for the given 8-bit gray value.
    `static byte[]` | `getBayerDither(int matrix, int gray255, boolean doubleMatrix)` Returns a byte array containing the dither pattern for the given 8-bit gray value.

    - ### Methods inherited from class java.lang.Object

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

- - ### Field Detail

    - #### DITHER_MATRIX_2X2

          public static final int DITHER_MATRIX_2X2

      Selects a 2x2 Bayer dither matrix (5 grayscales)
      See Also:
        Constant Field Values

    - #### DITHER_MATRIX_4X4

          public static final int DITHER_MATRIX_4X4

      Selects a 4x4 Bayer dither matrix (17 grayscales)
      See Also:
        Constant Field Values

    - #### DITHER_MATRIX_8X8

          public static final int DITHER_MATRIX_8X8

      Selects a 8x8 Bayer dither matrix (65 grayscales)
      See Also:
        Constant Field Values

  - ### Method Detail

    - #### getBayerBasePattern

          public static int[] getBayerBasePattern(int matrix)

      Returns the Bayer dither base pattern for a particular matrix size.
      Parameters:
        `matrix` - the matrix size (`DITHER_MATRIX_2X2`, `DITHER_MATRIX_4X4` or `DITHER_MATRIX_8X8`)
      Returns:
        the base pattern for the given size

    - #### getBayerDither

          public static byte[] getBayerDither(int matrix,
                                              int gray255,
                                              boolean doubleMatrix)

      Returns a byte array containing the dither pattern for the given 8-bit gray value.
      Parameters:
        `matrix` - the matrix size (`DITHER_MATRIX_2X2`, `DITHER_MATRIX_4X4` or `DITHER_MATRIX_8X8`)
        `gray255` - the gray value (0-255)
        `doubleMatrix` - true if the 4x4 matrix shall be doubled to a 8x8
      Returns:
        the dither pattern

    - #### getBayerDither

          public static byte[] getBayerDither(int matrix,
                                              Color col,
                                              boolean doubleMatrix)

      Returns a byte array containing the dither pattern for the given 8-bit gray value.
      Parameters:
        `matrix` - the matrix size (`DITHER_MATRIX_2X2`, `DITHER_MATRIX_4X4` or `DITHER_MATRIX_8X8`)
        `col` - the color
        `doubleMatrix` - true if the 4x4 matrix shall be doubled to a 8x8
      Returns:
        the dither pattern

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