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 // Do not take in account matching score below this when two ellipses are matched.
  13 let matchingScoreThreshold1 = 0.6
  14
  15 // All ellipsee with a score below this is removed.
  16 let matchingScoreThreshold2 = 2.
  17
  18 type private EllipseScoreFlaggedKd (matchingScore: float, e: Ellipse) =
  19     let mutable matchingScore = matchingScore
  20
  21     member this.Ellipse = e
  22
  23     member this.MatchingScore = matchingScore
  24
  25     member this.AddMatchingScore(score: float) =
  26         matchingScore <- matchingScore + score
  27
  28     member val Processed = false with get, set
  29     member val Removed = false with get, set
  30
  31     interface KdTree.I2DCoords with
  32         member this.X = this.Ellipse.Cx
  33         member this.Y = this.Ellipse.Cy
  34
  35
  36 type MatchingEllipses (radiusMin: float) =
  37     let ellipses = List<EllipseScoreFlaggedKd>()
  38
  39     member this.Add (e: Ellipse) =
  40         ellipses.Add(EllipseScoreFlaggedKd(0.0, e))
  41
  42     member this.Ellipses : Ellipse list =
  43         List.ofSeq ellipses |> List.map (fun e -> e.Ellipse)
  44
  45     // Process all ellipses and return ellipses ordered from the best score to the worst.
  46     member this.PrunedEllipses : Ellipse list =
  47         if ellipses.Count = 0
  48         then
  49             []
  50         else
  51             // 1) Create a kd-tree from the ellipses list.
  52             let tree = KdTree.Tree.BuildTree (List.ofSeq ellipses)
  53
  54             // 2) Compute the matching score of each ellipses.
  55             let windowSize = radiusMin
  56             for e in ellipses do
  57                 e.Processed <- true
  58                 let areaE = e.Ellipse.Area
  59                 let window = { KdTree.minX = e.Ellipse.Cx - windowSize / 2.0
  60                                KdTree.maxX = e.Ellipse.Cx + windowSize / 2.0
  61                                KdTree.minY = e.Ellipse.Cy - windowSize / 2.0
  62                                KdTree.maxY = e.Ellipse.Cy + windowSize / 2.0 }
  63                 for other in tree.Search window do
  64                     if not other.Processed
  65                     then
  66                         let areaOther = other.Ellipse.Area
  67                         match EEOver.EEOverlapArea e.Ellipse other.Ellipse with
  68                         | Some (commonArea, _, _) ->
  69                             let matchingScore = 2.0 * commonArea / (areaE + areaOther)
  70                             if matchingScore >= matchingScoreThreshold1
  71                             then
  72                                 other.AddMatchingScore(matchingScore)
  73                                 e.AddMatchingScore(matchingScore)
  74                         | _ -> ()
  75
  76             // 3) Sort ellipses by their score.
  77             ellipses.Sort(fun e1 e2 -> e2.MatchingScore.CompareTo(e1.MatchingScore))
  78
  79             // 4) Remove ellipses wich have a low score.
  80             let i = ellipses.BinarySearch(EllipseScoreFlaggedKd(matchingScoreThreshold2, Ellipse(0.0, 0.0, 0.0, 0.0, 0.0)),
  81                                           { new IComparer<EllipseScoreFlaggedKd> with
  82                                                 member this.Compare(e1, e2) = e2.MatchingScore.CompareTo(e1.MatchingScore) }) |> abs
  83             let nbToRemove = ellipses.Count - i
  84             if nbToRemove > 0
  85             then
  86                 for j in i .. nbToRemove - 1 do
  87                     ellipses.[j].Removed <- true
  88                 ellipses.RemoveRange(i, nbToRemove)
  89
  90             // 5) Remove ellipses whose center is into an ellipse with a better score
  91             for e in ellipses do
  92                 if not e.Removed
  93                 then
  94                     let window = { KdTree.minX = e.Ellipse.Cx - e.Ellipse.A
  95                                    KdTree.maxX = e.Ellipse.Cx + e.Ellipse.A
  96                                    KdTree.minY = e.Ellipse.Cy - e.Ellipse.A
  97                                    KdTree.maxY = e.Ellipse.Cy + e.Ellipse.A }
  98                     for other in tree.Search window do
  99                         if not other.Removed && other.MatchingScore < e.MatchingScore
 100                         then
 101                             if e.Ellipse.Scale(0.8).Contains other.Ellipse.Cx other.Ellipse.Cy
 102                             then
 103                                 other.Removed <- true
 104             ellipses.RemoveAll(fun e -> e.Removed) |> ignore
 105
 106             List.ofSeq ellipses |> List.map (fun e -> e.Ellipse)
 107
 108
 109