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

   1 package eu.svjatoslav.imagesqueeze.codec;
   2
   3 import java.io.IOException;
   4
   5 /**
   6  * Since it is a lossy codec, instead of storing
   7  * exact values, approximated values are stored
   8  * to save on bit count.
   9  */
  10
  11 public class Approximator implements Comparable<Approximator> {
  12
  13         public Table yTable = new Table();
  14         public Table uTable = new Table();
  15         public Table vTable = new Table();
  16
  17         public Approximator(){
  18         }
  19
  20         public int compareTo(Approximator o) {
  21                 int result = yTable.compareTo(o.yTable);
  22                 if (result != 0) return result;
  23
  24                 result = uTable.compareTo(o.uTable);
  25                 if (result != 0) return result;
  26
  27                 result = vTable.compareTo(o.vTable);
  28                 return result;
  29         }
  30
  31         public void initialize(){
  32                 yTable.reset();
  33                 uTable.reset();
  34                 vTable.reset();
  35
  36                 yTable.addEntry(0, 6, 0);
  37                 yTable.addEntry(27, 30, 4);
  38                 yTable.addEntry(255, 255, 6);
  39
  40                 uTable.addEntry(0, 9, 0);
  41                 uTable.addEntry(27, 30, 4);
  42                 uTable.addEntry(255, 255, 6);
  43
  44                 vTable.addEntry(0, 9, 0);
  45                 vTable.addEntry(27, 30, 4);
  46                 vTable.addEntry(255, 255, 6);
  47
  48                 computeLookupTables();
  49         }
  50
  51         public void save(BitOutputStream outputStream) throws IOException{
  52                 yTable.save(outputStream);
  53                 uTable.save(outputStream);
  54                 vTable.save(outputStream);
  55         }
  56
  57         public void load(BitInputStream inputStream) throws IOException {
  58                 yTable.load(inputStream);
  59                 uTable.load(inputStream);
  60                 vTable.load(inputStream);
  61         }
  62
  63         public void computeLookupTables(){
  64                 yTable.computeLookupTables();
  65                 uTable.computeLookupTables();
  66                 vTable.computeLookupTables();
  67         }
  68
  69 }