Parasitemia/Parasitemia/MatchingEllipses.fs

   1 module MatchingEllipses
   2
   3 open System
   4 open System.Linq
   5 open System.Collections
   6 open System.Collections.Generic
   7
   8 open Types
   9 open Utils
  10
  11
  12 let matchingScoreThreshold1 = 0.6
  13 let matchingScoreThreshold2 = 1.0
  14
  15 type EllipseScore (matchingScore: float, e: Ellipse) =
  16     let mutable matchingScore = matchingScore
  17
  18     member this.MatchingScore = matchingScore
  19     member this.Ellipse = e
  20     member val Processed = false with get, set
  21     member val Removed = false with get, set
  22
  23     member this.AddMatchingScore(score: float) =
  24         matchingScore <- matchingScore + score
  25
  26     interface KdTree.I2DCoords with
  27         member this.X = e.Cx
  28         member this.Y = e.Cy
  29
  30 type MatchingEllipses (radiusMin: float) =
  31     let ellipses = List<EllipseScore>()
  32
  33     member this.Add (e: Ellipse) =
  34         ellipses.Add(EllipseScore(0.0, e))
  35
  36     member this.Ellipses : Ellipse list =
  37         // 1) Create a kd-tree from the ellipses list.
  38         let tree = KdTree.Tree.buildTree (List.ofSeq ellipses)
  39
  40         // 2) Compute the matching score of each ellipses.
  41         let windowSize = radiusMin
  42         for e in ellipses do
  43             e.Processed <- true
  44             let areaE = e.Ellipse.Area
  45             let window = { KdTree.minX = e.Ellipse.Cx - windowSize / 2.0
  46                            KdTree.maxX = e.Ellipse.Cx + windowSize / 2.0
  47                            KdTree.minY = e.Ellipse.Cy - windowSize / 2.0
  48                            KdTree.maxY = e.Ellipse.Cy + windowSize / 2.0 }
  49             for other in KdTree.Tree.search tree window do
  50                 if not other.Processed
  51                 then
  52                     let areaOther = other.Ellipse.Area
  53                     match EEOver.EEOverlapArea e.Ellipse other.Ellipse with
  54                     | Some (commonArea, _, _) ->
  55                         let matchingScore = 2.0 * commonArea / (areaE + areaOther)
  56                         if matchingScore >= matchingScoreThreshold1
  57                         then
  58                             other.AddMatchingScore(matchingScore)
  59                             e.AddMatchingScore(matchingScore)
  60                     | _ -> ()
  61
  62         // 3) Sort ellipses by their score.
  63         ellipses.Sort(fun e1 e2 -> e2.MatchingScore.CompareTo(e1.MatchingScore))
  64
  65         // 4) Remove ellipses wich have a low score.
  66         let i = ellipses.BinarySearch(EllipseScore(matchingScoreThreshold2, Ellipse(0.0, 0.0, 0.0, 0.0, 0.0)),
  67                                       { new IComparer<EllipseScore> with
  68                                             member this.Compare(e1, e2) = e2.MatchingScore.CompareTo(e1.MatchingScore) }) |> abs
  69         let nbToRemove = ellipses.Count - i
  70         if nbToRemove > 0
  71         then
  72             for j in i .. nbToRemove - 1 do
  73                 ellipses.[j].Removed <- true
  74             ellipses.RemoveRange(i, nbToRemove)
  75
  76         // 5) Remove ellipses whose center is into an ellipse with a better score
  77         for e in ellipses do
  78             if not e.Removed
  79             then
  80                 let window = { KdTree.minX = e.Ellipse.Cx - e.Ellipse.A
  81                                KdTree.maxX = e.Ellipse.Cx + e.Ellipse.A
  82                                KdTree.minY = e.Ellipse.Cy - e.Ellipse.A
  83                                KdTree.maxY = e.Ellipse.Cy + e.Ellipse.A }
  84                 for other in KdTree.Tree.search tree window do
  85                     if not other.Removed && other.MatchingScore < e.MatchingScore
  86                     then
  87                         if e.Ellipse.Contains other.Ellipse.Cx other.Ellipse.Cy
  88                         then
  89                             other.Removed <- true
  90         ellipses.RemoveAll(fun e -> e.Removed) |> ignore
  91
  92         List.ofSeq ellipses |> List.map (fun e -> e.Ellipse)
  93
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  97