// returns 5 local max points (1 for each fingertip) and 4 local min points (spaces between fingers)
public bool FindFingerPoints(List <Point> path, Point centroid, out List <APair <int, double> > maximums, out List <APair <int, double> > minimums)
{
// find distances to centroid for each path point
List <double> distances = new List <double>();
for (int i = 0; i < path.Count; ++i)
{
Point p = path[i];
if (p != null)
{
double dist = BitMatrix.Distance(p, centroid);
distances.Add(dist);
}
}
List <double> blurredDistances = ListBlur(distances);
maximums = FindMaximums(blurredDistances);
if (maximums.Count != MAX_COUNT)
{
minimums = new List <APair <int, double> >();
return(false);
}
minimums = FindMinimums(blurredDistances, maximums);
if (minimums.Count != MIN_COUNT)
{
return(false);
}
return(true);
}
// calculates distances between max/min points and surface areas for each finger
public List <double> FindFingerFeatures(BitMatrix bm, List <Point> path, Point centroid, List <APair <int, double> > maximums, List <APair <int, double> > minimums)
{
// get finger/hole points
List <Point> fingers = new List <Point>();
for (int i = 0; i < maximums.Count; ++i)
{
fingers.Add(path[maximums[i].First]);
}
List <Point> holes = new List <Point>();
for (int i = 0; i < minimums.Count; ++i)
{
holes.Add(path[minimums[i].First]);
}
List <double> features = new List <double>
{
// first add left side distances
BitMatrix.Distance(fingers[0], holes[0]),
BitMatrix.Distance(fingers[1], holes[1]),
BitMatrix.Distance(fingers[2], holes[2]),
BitMatrix.Distance(fingers[3], holes[3]),
// then add right side distances
BitMatrix.Distance(fingers[1], holes[0]),
BitMatrix.Distance(fingers[2], holes[1]),
BitMatrix.Distance(fingers[3], holes[2]),
BitMatrix.Distance(fingers[4], holes[3])
};
// now find points before and after first hole to calculate surface areas
int preI = maximums[0].First * 2 - minimums[0].First;
if (preI < 0)
{
preI = 0;
}
else if (preI > path.Count - 1)
{
preI = path.Count - 1;
}
Point preHole = path[preI];
Point postHole;
// find point before first hole
while (preI >= 1 && BitMatrix.Distance(preHole, fingers[0]) < BitMatrix.Distance(fingers[0], holes[0]))
{
preHole = path[--preI];
}
while (preI < path.Count - 2 && BitMatrix.Distance(preHole, fingers[0]) > BitMatrix.Distance(fingers[0], holes[0]))
{
preHole = path[++preI];
}
// find point after last hole
int maxId = MAX_COUNT - 1;
int minId = MIN_COUNT - 1;
int postI = maximums[maxId].First * 2 - minimums[minId].First;
if (postI < 0)
{
postI = 0;
}
else if (postI > path.Count - 1)
{
postI = path.Count - 1;
}
postHole = path[postI];
while (postI < path.Count - 2 && BitMatrix.Distance(postHole, fingers[maxId]) < BitMatrix.Distance(fingers[maxId], holes[minId]))
{
postHole = path[++postI];
}
while (postI >= 1 && BitMatrix.Distance(postHole, fingers[maxId]) > BitMatrix.Distance(fingers[maxId], holes[minId]))
{
postHole = path[--postI];
}
BitMatrix fbm = new BitMatrix(bm);
fbm.FillArea(centroid);
// #TODO LS generate surface area data
//features.Add(Math.Sqrt(bm.GetSurface(fbm, preHole, holes[0])));
//features.Add(Math.Sqrt(bm.GetSurface(fbm, holes[0], holes[1])));
//features.Add(Math.Sqrt(bm.GetSurface(fbm, holes[1], holes[2])));
//features.Add(Math.Sqrt(bm.GetSurface(fbm, holes[2], holes[3])));
//features.Add(Math.Sqrt(bm.GetSurface(fbm, holes[3], postHole)));
return(features);
}