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.
  14
  15 type private EllipseScoreFlaggedKd (matchingScore: float, e: Ellipse) =
  16     let mutable matchingScore = matchingScore
  17
  18     member this.Ellipse = e
  19
  20     member this.MatchingScore = matchingScore
  21     member this.AddMatchingScore(score: float) =
  22         matchingScore <- matchingScore + score
  23
  24     member val Processed = false with get, set
  25     member val Removed = false with get, set
  26
  27     interface KdTree.I2DCoords with
  28         member this.X = this.Ellipse.Cx
  29         member this.Y = this.Ellipse.Cy
  30
  31
  32 type MatchingEllipses (radiusMin: float) =
  33     let ellipses = List<EllipseScoreFlaggedKd>()
  34
  35     member this.Add (e: Ellipse) =
  36         ellipses.Add(EllipseScoreFlaggedKd(0.0, e))
  37
  38     member this.Ellipses : Ellipse list =
  39         List.ofSeq ellipses |> List.map (fun e -> e.Ellipse)
  40
  41     member this.PrunedEllipses : Ellipse list =
  42         if ellipses.Count = 0
  43         then
  44             []
  45         else
  46             // 1) Create a kd-tree from the ellipses list.
  47             let tree = KdTree.Tree.BuildTree (List.ofSeq ellipses)
  48
  49             // 2) Compute the matching score of each ellipses.
  50             let windowSize = radiusMin
  51             for e in ellipses do
  52                 e.Processed <- true
  53                 let areaE = e.Ellipse.Area
  54                 let window = { KdTree.minX = e.Ellipse.Cx - windowSize / 2.0
  55                                KdTree.maxX = e.Ellipse.Cx + windowSize / 2.0
  56                                KdTree.minY = e.Ellipse.Cy - windowSize / 2.0
  57                                KdTree.maxY = e.Ellipse.Cy + windowSize / 2.0 }
  58                 for other in tree.Search window do
  59                     if not other.Processed
  60                     then
  61                         let areaOther = other.Ellipse.Area
  62                         match EEOver.EEOverlapArea e.Ellipse other.Ellipse with
  63                         | Some (commonArea, _, _) ->
  64                             let matchingScore = 2.0 * commonArea / (areaE + areaOther)
  65                             if matchingScore >= matchingScoreThreshold1
  66                             then
  67                                 other.AddMatchingScore(matchingScore)
  68                                 e.AddMatchingScore(matchingScore)
  69                         | _ -> ()
  70
  71             // 3) Sort ellipses by their score.
  72             ellipses.Sort(fun e1 e2 -> e2.MatchingScore.CompareTo(e1.MatchingScore))
  73
  74             // 4) Remove ellipses wich have a low score.
  75             let i = ellipses.BinarySearch(EllipseScoreFlaggedKd(matchingScoreThreshold2, Ellipse(0.0, 0.0, 0.0, 0.0, 0.0)),
  76                                           { new IComparer<EllipseScoreFlaggedKd> with
  77                                                 member this.Compare(e1, e2) = e2.MatchingScore.CompareTo(e1.MatchingScore) }) |> abs
  78             let nbToRemove = ellipses.Count - i
  79             if nbToRemove > 0
  80             then
  81                 for j in i .. nbToRemove - 1 do
  82                     ellipses.[j].Removed <- true
  83                 ellipses.RemoveRange(i, nbToRemove)
  84
  85             // 5) Remove ellipses whose center is into an ellipse with a better score
  86             for e in ellipses do
  87                 if not e.Removed
  88                 then
  89                     let window = { KdTree.minX = e.Ellipse.Cx - e.Ellipse.A
  90                                    KdTree.maxX = e.Ellipse.Cx + e.Ellipse.A
  91                                    KdTree.minY = e.Ellipse.Cy - e.Ellipse.A
  92                                    KdTree.maxY = e.Ellipse.Cy + e.Ellipse.A }
  93                     for other in tree.Search window do
  94                         if not other.Removed && other.MatchingScore < e.MatchingScore
  95                         then
  96                             if e.Ellipse.Contains other.Ellipse.Cx other.Ellipse.Cy
  97                             then
  98                                 other.Removed <- true
  99             ellipses.RemoveAll(fun e -> e.Removed) |> ignore
 100
 101             List.ofSeq ellipses |> List.map (fun e -> e.Ellipse)
 102
 103
 104