src/main/java/eu/svjatoslav/imagesqueeze/codec/Approximator.java

   1 /*
   2  * Imagesqueeze - Image codec optimized for photos.
   3  * Copyright (C) 2012, Svjatoslav Agejenko, svjatoslav@svjatoslav.eu
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of version 2 of the GNU General Public License
   7  * as published by the Free Software Foundation.
   8  */
   9
  10 package eu.svjatoslav.imagesqueeze.codec;
  11
  12 import java.io.IOException;
  13
  14 import eu.svjatoslav.commons.data.BitInputStream;
  15 import eu.svjatoslav.commons.data.BitOutputStream;
  16
  17 /**
  18  * Since it is a lossy codec, instead of storing exact values, approximated
  19  * values are stored to save on bit count.
  20  */
  21
  22 public class Approximator implements Comparable<Approximator> {
  23
  24         public Table yTable = new Table();
  25         public Table uTable = new Table();
  26         public Table vTable = new Table();
  27
  28         public Approximator() {
  29         }
  30
  31         @Override
  32         public int compareTo(final Approximator o) {
  33                 int result = yTable.compareTo(o.yTable);
  34                 if (result != 0) {
  35                         return result;
  36                 }
  37
  38                 result = uTable.compareTo(o.uTable);
  39                 if (result != 0) {
  40                         return result;
  41                 }
  42
  43                 result = vTable.compareTo(o.vTable);
  44                 return result;
  45         }
  46
  47         public void computeLookupTables() {
  48                 yTable.computeLookupTables();
  49                 uTable.computeLookupTables();
  50                 vTable.computeLookupTables();
  51         }
  52
  53         public void initialize() {
  54                 yTable.reset();
  55                 uTable.reset();
  56                 vTable.reset();
  57
  58                 yTable.addEntry(0, 6, 0);
  59                 yTable.addEntry(27, 30, 4);
  60                 yTable.addEntry(255, 255, 6);
  61
  62                 uTable.addEntry(0, 9, 0);
  63                 uTable.addEntry(27, 30, 4);
  64                 uTable.addEntry(255, 255, 6);
  65
  66                 vTable.addEntry(0, 9, 0);
  67                 vTable.addEntry(27, 30, 4);
  68                 vTable.addEntry(255, 255, 6);
  69
  70                 computeLookupTables();
  71         }
  72
  73         public void load(final BitInputStream inputStream) throws IOException {
  74                 yTable.load(inputStream);
  75                 uTable.load(inputStream);
  76                 vTable.load(inputStream);
  77         }
  78
  79         public void save(final BitOutputStream outputStream) throws IOException {
  80                 yTable.save(outputStream);
  81                 uTable.save(outputStream);
  82                 vTable.save(outputStream);
  83         }
  84
  85 }