com.google.zxing

Class 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).

    • Constructor Detail

      • InvertedLuminanceSource

        public InvertedLuminanceSource(LuminanceSource delegate)

    • Method Detail

      • 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.