Package com.google.zxing

Class InvertedLuminanceSource

java.lang.Object
com.google.zxing.LuminanceSource
com.google.zxing.InvertedLuminanceSource
public final class InvertedLuminanceSource extends LuminanceSource
A wrapper implementation of LuminanceSource which inverts the luminances it returns -- black becomes white and vice versa, and each value becomes (255-value).
Author:
Sean Owen

  • Constructor Details

    • InvertedLuminanceSource

      public InvertedLuminanceSource(LuminanceSource delegate)

  • Method Details

    • getRow

      public byte[] getRow(int y, byte[] row)
      Description copied from class: LuminanceSource
      Fetches one row of luminance data from the underlying platform's bitmap. Values range from 0 (black) to 255 (white). Because Java does not have an unsigned byte type, callers will have to bitwise and with 0xff for each value. It is preferable for implementations of this method to only fetch this row rather than the whole image, since no 2D Readers may be installed and getMatrix() may never be called.
      Specified by:
      getRow in class LuminanceSource
      Parameters:
      y - The row to fetch, which must be in [0,getHeight())
      row - An optional preallocated array. If null or too small, it will be ignored. Always use the returned object, and ignore the .length of the array.
      Returns:
      An array containing the luminance data.

    • getMatrix

      public byte[] getMatrix()
      Description copied from class: LuminanceSource
      Fetches luminance data for the underlying bitmap. Values should be fetched using: int luminance = array[y * width + x] & 0xff
      Specified by:
      getMatrix in class LuminanceSource
      Returns:
      A row-major 2D array of luminance values. Do not use result.length as it may be larger than width * height bytes on some platforms. Do not modify the contents of the result.

    • isCropSupported

      public boolean isCropSupported()
      Overrides:
      isCropSupported in class LuminanceSource
      Returns:
      Whether this subclass supports cropping.

    • crop

      public LuminanceSource crop(int left, int top, int width, int height)
      Description copied from class: LuminanceSource
      Returns a new object with cropped image data. Implementations may keep a reference to the original data rather than a copy. Only callable if isCropSupported() is true.
      Overrides:
      crop in class LuminanceSource
      Parameters:
      left - The left coordinate, which must be in [0,getWidth())
      top - The top coordinate, which must be in [0,getHeight())
      width - The width of the rectangle to crop.
      height - The height of the rectangle to crop.
      Returns:
      A cropped version of this object.

    • isRotateSupported

      public boolean isRotateSupported()
      Overrides:
      isRotateSupported in class LuminanceSource
      Returns:
      Whether this subclass supports counter-clockwise rotation.

    • invert

      public LuminanceSource invert()
      Overrides:
      invert in class LuminanceSource
      Returns:
      original delegate LuminanceSource since invert undoes itself

    • rotateCounterClockwise

      public LuminanceSource rotateCounterClockwise()
      Description copied from class: LuminanceSource
      Returns a new object with rotated image data by 90 degrees counterclockwise. Only callable if LuminanceSource.isRotateSupported() is true.
      Overrides:
      rotateCounterClockwise in class LuminanceSource
      Returns:
      A rotated version of this object.

    • rotateCounterClockwise45

      public LuminanceSource rotateCounterClockwise45()
      Description copied from class: LuminanceSource
      Returns a new object with rotated image data by 45 degrees counterclockwise. Only callable if LuminanceSource.isRotateSupported() is true.
      Overrides:
      rotateCounterClockwise45 in class LuminanceSource
      Returns:
      A rotated version of this object.