private static void LearnRotations(List<Patch> patches, Tree tree)
{
for (int iters = 0; iters < 2; iters++)
{
// Loop over the patches
foreach (var p in patches)
{
int bestCount = 0;
int bestAngle = 0;
var oldnd = p.NodeIndex;
var newnd = -1;
// Loop over rotations
for (int angle = 0; angle < 360; angle += 5)
{
p.Angle = angle;
// Apply the tree to the patch
var leaf = tree.Apply(p);
// See if bigger, if so store best rotation
if (leaf.Count > bestCount)
{
bestCount = leaf.Count;
bestAngle = angle;
newnd = leaf.Index;
}
}
// Move to node for best rotation
p.NodeIndex = newnd;
p.Angle = bestAngle;
tree.Nodes[oldnd].Count--;
tree.Nodes[newnd].Count++;
}
}
}
public void AddLayer(Tree tree, List<Patch> patches)
{
// Get a set of possible features
var features = GetFeatures(patches[0],100);
var leafNodes = tree.Nodes.Where(nd => nd.IsLeaf).ToList();
// For each feature, apply to all patches + count trues and falses, compute metric
foreach (var f in features)
{
int[] trueCount = new int[tree.Nodes.Count];
foreach (var p in patches)
{
if (f.ComputeFeature(p))
{
trueCount[p.NodeIndex]++;
}
}
foreach (var nd in leafNodes)
{
double metric = Math.Abs(trueCount[nd.Index] - (nd.Count - trueCount[nd.Index]));
if (metric < nd.bestMetric)
{
nd.Feature = f;
nd.bestMetric = metric;
}
}
}
// Split leaf nodes using best feature
foreach(var nd in leafNodes)
{
//Console.WriteLine("Feature for node " + nd.Index + ": " + nd.Feature);
nd.Left = tree.AddNode();
nd.Right = tree.AddNode();
}
// Update which node each patch is at
foreach (var p in patches)
{
var nd = tree.Nodes[p.NodeIndex];
if (nd.Feature.ComputeFeature(p))
{
p.NodeIndex = nd.Right.Index;
nd.Right.Count++;
}
else
{
p.NodeIndex= nd.Left.Index;
nd.Left.Count++;
}
}
}
public Tree Learn(int depth, List<Patch> patches)
{
var tree = new Tree();
tree.Root.Count = patches.Count;
Console.Write("Training tree on "+patches.Count+" patches.");
foreach (var p in patches) p.NodeIndex = 0;
for (int d = 0; d < depth; d++)
{
Console.Write(".");
AddLayer(tree, patches);
}
Console.WriteLine();
return tree;
}
private static void LearnTranslations(List<Patch> patches, Tree tree)
{
int max = 16; int step = 2;
// Loop over the patches
foreach (var p in patches)
{
int bestCount = 0;
int bestX = 0; int bestY = 0;
var oldnd = p.NodeIndex;
var newnd = -1;
// Loop over rotations
for (int y = -max; y <= max; y += step)
{
for (int x = -max; x <= max; x += step)
{
p.NudgeX = x;
p.NudgeY = y;
if ((x + p.Left < 0) || (x + p.Left + p.Width >= p.Image.Bitmap.PixelWidth)) continue;
if ((y + p.Top < 0) || (y + p.Top + p.Height >= p.Image.Bitmap.PixelHeight)) continue;
// Apply the tree to the patch
var leaf = tree.Apply(p);
// See if bigger, if so store best rotation
if (leaf.Count > bestCount)
{
bestCount = leaf.Count;
bestX = x; bestY = y;
newnd = leaf.Index;
}
}
}
// Move to node for best rotation
p.NodeIndex = newnd;
p.NudgeX = bestX;
p.NudgeY = bestY;
tree.Nodes[oldnd].Count--;
tree.Nodes[newnd].Count++;
}
}
