Class PNGPredictor


  • public class PNGPredictor
    extends Predictor
    Undo prediction based on the PNG algorithm.
    • Constructor Summary

      Constructors 
      Constructor Description
      PNGPredictor()
      Creates a new instance of PNGPredictor
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      protected void doAverageLine​(byte[] curLine, byte[] prevLine)
      Return the value of the average algorithm on the line (compare bytes to the average of the previous byte of the same color and the same byte on the previous line)
      protected void doPaethLine​(byte[] curLine, byte[] prevLine)
      Return the value of the average algorithm on the line (compare bytes to the average of the previous byte of the same color and the same byte on the previous line)
      protected void doSubLine​(byte[] curLine)
      Return the value of the Sub algorithm on the line (compare bytes to the previous byte of the same color on this line).
      protected void doUpLine​(byte[] curLine, byte[] prevLine)
      Return the value of the up algorithm on the line (compare bytes to the same byte in the previous line)
      protected int paeth​(int left, int up, int upLeft)
      The paeth algorithm
      java.nio.ByteBuffer unpredict​(java.nio.ByteBuffer imageData)
      Undo data based on the png algorithm
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Constructor Detail

      • PNGPredictor

        public PNGPredictor()
        Creates a new instance of PNGPredictor
    • Method Detail

      • unpredict

        public java.nio.ByteBuffer unpredict​(java.nio.ByteBuffer imageData)
                                      throws java.io.IOException
        Undo data based on the png algorithm
        Specified by:
        unpredict in class Predictor
        Throws:
        java.io.IOException
      • doSubLine

        protected void doSubLine​(byte[] curLine)
        Return the value of the Sub algorithm on the line (compare bytes to the previous byte of the same color on this line).
      • doUpLine

        protected void doUpLine​(byte[] curLine,
                                byte[] prevLine)
        Return the value of the up algorithm on the line (compare bytes to the same byte in the previous line)
      • doAverageLine

        protected void doAverageLine​(byte[] curLine,
                                     byte[] prevLine)
        Return the value of the average algorithm on the line (compare bytes to the average of the previous byte of the same color and the same byte on the previous line)
      • doPaethLine

        protected void doPaethLine​(byte[] curLine,
                                   byte[] prevLine)
        Return the value of the average algorithm on the line (compare bytes to the average of the previous byte of the same color and the same byte on the previous line)
      • paeth

        protected int paeth​(int left,
                            int up,
                            int upLeft)
        The paeth algorithm