Class PlanarYUVLuminanceSource

java.lang.Object
com.google.zxing.LuminanceSource
com.google.zxing.PlanarYUVLuminanceSource

public final class PlanarYUVLuminanceSource extends LuminanceSource
This object extends LuminanceSource around an array of YUV data returned from the camera driver, with the option to crop to a rectangle within the full data. This can be used to exclude superfluous pixels around the perimeter and speed up decoding. It works for any pixel format where the Y channel is planar and appears first, including YCbCr_420_SP and YCbCr_422_SP.
  • Field Details

    • THUMBNAIL_SCALE_FACTOR

      private static final int THUMBNAIL_SCALE_FACTOR
      See Also:
    • yuvData

      private final byte[] yuvData
    • dataWidth

      private final int dataWidth
    • dataHeight

      private final int dataHeight
    • left

      private final int left
    • top

      private final int top
  • Constructor Details

    • PlanarYUVLuminanceSource

      public PlanarYUVLuminanceSource(byte[] yuvData, int dataWidth, int dataHeight, int left, int top, int width, int height, boolean reverseHorizontal)
  • 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.
    • renderThumbnail

      public int[] renderThumbnail()
    • getThumbnailWidth

      public int getThumbnailWidth()
      Returns:
      width of image from renderThumbnail()
    • getThumbnailHeight

      public int getThumbnailHeight()
      Returns:
      height of image from renderThumbnail()
    • reverseHorizontal

      private void reverseHorizontal(int width, int height)