GestureDetectionApp/GestureRecognition/src/at/mus/recognition/DTW.java

   1 package at.mus.recognition;
   2
   3 import java.util.ArrayList;
   4 import java.util.Arrays;
   5 import java.util.List;
   6
   7 public class DTW implements IRecognizer {
   8
   9         @Override
  10         public Result recognize(List<ICoordinate> rawPoints, List<Template> templates, int n_, double size, ICoordinate origin) {
  11                 int[] score = new int[templates.size()];
  12                 int i = 0;
  13                 int minIndex = 0;
  14
  15                 List<ICoordinate> points = quantize(compress(rawPoints));
  16                 for(Template t : templates) {
  17                         List<ICoordinate> pointList = new ArrayList<ICoordinate>(Arrays.asList(t.points));
  18                         score[i] = this.dist(points, quantize(compress(pointList)));
  19                         if(score[i] < score[minIndex]) minIndex = i;
  20                         ++i;
  21                 }
  22
  23                 for(int s : score) {
  24                         System.err.println(s);
  25                 }
  26
  27                 return new Result(templates.get(minIndex), score[minIndex]);
  28         }
  29
  30         private int dist(List<ICoordinate> s, List<ICoordinate> t) {
  31                 int m = t.size(), n = s.size();
  32                 int[][] dtw = new int[n][m];
  33                 int cost;
  34
  35                 for(int i=0; i < m; ++i) { dtw[0][i] = Integer.MAX_VALUE; }
  36                 for(int i=0; i < n; ++i) { dtw[i][0] = Integer.MAX_VALUE; }
  37                 dtw[0][0] = 0;
  38
  39                 for(int i=1; i < n; ++i) {
  40                         for(int j=1; j < m; ++j) {
  41                                 cost = (int)s.get(i).distance(t.get(j));
  42                                 dtw[i][j] = cost + Math.min(
  43                                                 dtw[i-1][j],  // insertion
  44                                                 Math.min(dtw[i][j-1],  // deletion
  45                                                                 dtw[i-1][j-1])); // match
  46                         }
  47                 }
  48
  49                 return dtw[n-1][m-1];
  50         }
  51
  52         private List<ICoordinate> compress(List<ICoordinate> points) {
  53                 List<ICoordinate> compressed = new ArrayList<ICoordinate>();
  54                 int windowSize = 10, stepSize = 6;
  55
  56                 for(int i = 0, l = points.size(); i+windowSize < l; i += stepSize) {
  57                         ICoordinate total = new Acceleration(0, 0, 0);
  58                         for(int j = 0; j < windowSize; ++j) {
  59                                 total = total.add(points.get(i+j));
  60                         }
  61                         compressed.add(total.divide(windowSize));
  62                 }
  63
  64                 return compressed;
  65         }
  66
  67         private List<ICoordinate> quantize(List<ICoordinate> points) {
  68                 List<ICoordinate> quantized = new ArrayList<ICoordinate>();
  69
  70                 for(ICoordinate coord : points) {
  71                         Acceleration a = (Acceleration)coord;
  72                         quantized.add(new Acceleration(quantize(a.x), quantize(a.y), quantize(a.z)));
  73                 }
  74
  75                 return quantized;
  76         }
  77         private float quantize(float f) {
  78                 if(f < 0) return -quantizeSymm(f);
  79                 return quantizeSymm(f);
  80         }
  81
  82         private float quantizeSymm(float f) {
  83                 final float g = 10f;//9.8f;
  84                 if(f > 2*g) return 16;
  85                 if(f > g) return 11+(int)(5*(f-g)/g); // 11-15
  86                 if(f > 0) return 1+(int)(10*f/g); // 1-10
  87                 return 0;
  88         }
  89 }