Parasitemia/Parasitemia/Classifier.fs

   1 module Classifier
   2
   3 open System
   4 open System.Collections.Generic
   5 open System.Drawing
   6
   7 open Emgu.CV
   8 open Emgu.CV.Structure
   9
  10 open Types
  11 open Utils
  12
  13
  14 type private EllipseFlaggedKd (e: Ellipse) =
  15     inherit Ellipse (e.Cx, e.Cy, e.A, e.B, e.Alpha)
  16
  17     member val Removed = false with get, set
  18
  19     interface KdTree.I2DCoords with
  20         member this.X = this.Cx
  21         member this.Y = this.Cy
  22
  23
  24 let findCells (ellipses: Ellipse list) (parasites: ParasitesMarker.Result) (fg: Image<Gray, byte>) (config: Config.Config) : Cell list =
  25     if ellipses.IsEmpty
  26     then
  27         []
  28     else
  29         let infection = parasites.infection.Copy() // To avoid to modify the parameter.
  30
  31         // This is the minimum window size to check if other ellipses touch 'e'.
  32         let searchRegion (e: Ellipse) = { KdTree.minX = e.Cx - (e.A + config.maxRBCSize) * config.scale
  33                                           KdTree.maxX = e.Cx + (e.A + config.maxRBCSize) * config.scale
  34                                           KdTree.minY = e.Cy - (e.A + config.maxRBCSize) * config.scale
  35                                           KdTree.maxY = e.Cy + (e.A + config.maxRBCSize) * config.scale }
  36
  37         // The minimum window to contain a given ellipse.
  38         let ellipseWindow (e: Ellipse) =
  39             let cx, cy = roundInt e.Cx, roundInt e.Cy
  40             let a = int (e.A + 0.5)
  41             cx - a, cy - a, cx + a, cy + a
  42
  43         // 1) Remove ellipses touching the edges.
  44         let ellipsesInside = ellipses |> List.map (fun e ->
  45             EllipseFlaggedKd (e, Removed = e.isOutside (float fg.Width) (float fg.Height)))
  46
  47         // 2) Associate touching ellipses with each ellipses.
  48         let tree = KdTree.Tree.BuildTree ellipsesInside
  49         let neighbors (e: Ellipse) : (EllipseFlaggedKd * PointD * PointD) list =
  50             tree.Search (searchRegion e)
  51                 // We only keep the ellipses touching 'e'.
  52                 |> List.choose (fun otherE ->
  53                     match EEOver.EEOverlapArea e otherE with
  54                     | Some (area, px, py) when area > 0.0 && px.Length >= 2 && py.Length >= 2 ->
  55                         Some (otherE, PointD(px.[0], py.[0]), PointD(px.[1], py.[1]))
  56                     | _ ->
  57                         None )
  58
  59         let ellipsesWithNeigbors = ellipsesInside |> List.choose (fun e -> if e.Removed then None else Some (e, neighbors e))
  60
  61         // 3) Remove ellipse with a lower percentage of foreground.
  62         let fgData = fg.Data
  63         for e, neighbors in ellipsesWithNeigbors do
  64             let minX, minY, maxX, maxY = ellipseWindow e
  65
  66             let mutable totalElement = 0
  67             let mutable fgElement = 0
  68
  69             for y in minY .. maxY do
  70                 for x in minX .. maxX do
  71                     let yf, xf = float y, float x
  72                     if e.Contains xf yf && neighbors |> List.forall (fun (otherE, _, _) -> not <| otherE.Contains xf yf)
  73                     then
  74                         totalElement <- totalElement + 1
  75                         if fgData.[y, x, 0] > 0uy
  76                         then
  77                             fgElement <- fgElement + 1
  78
  79             if totalElement < config.minimumCellArea || (float fgElement) / (float totalElement) < config.percentageOfFgValidCell
  80             then
  81                 e.Removed <- true
  82
  83         // 3) Define pixels associated to each ellipse and create the cells.
  84
  85         // Return 'true' if the point 'p' is owned by e.
  86         // The lines represents all intersections with other ellipses.
  87         let pixelOwnedByE (p: PointD) (e: Ellipse) (lines: Line list) =
  88             e.Contains p.X p.Y &&
  89             seq {
  90                 let c = PointD(e.Cx, e.Cy)
  91                 for d1 in lines do
  92                     let d2 = Utils.lineFromTwoPoints c p
  93                     let p' = Utils.pointFromTwoLines d1 d2
  94                     yield sign (c.X - p.X) <> sign (c.X - p'.X) || Utils.squaredDistanceTwoPoints c p' > Utils.squaredDistanceTwoPoints c p // 'false' -> the point is owned by another ellipse.
  95             } |> Seq.forall id
  96
  97
  98         ellipsesWithNeigbors
  99         |> List.choose (fun (e, neighbors) ->
 100             if e.Removed
 101             then
 102                 None
 103             else
 104                 let minX, minY, maxX, maxY = ellipseWindow e
 105
 106                 let infectedPixels = List<Point>()
 107                 let mutable stainPixels = 0
 108                 let mutable darkStainPixels = 0
 109                 let mutable nbElement = 0
 110
 111                 let mutable stain_x = 0.0
 112                 let mutable stain_x2 = 0.0
 113                 let mutable stain_y = 0.0
 114                 let mutable stain_y2 = 0.0
 115
 116                 let mutable sumCoords_y = 0
 117                 let mutable sumCoords_x = 0
 118
 119                 let elements = new Matrix<byte>(maxY - minY + 1, maxX - minX + 1)
 120                 for y in minY .. maxY do
 121                     for x in minX .. maxX do
 122                         let p = PointD(float x, float y)
 123                         if pixelOwnedByE p e (neighbors |> List.choose (fun (otherE, p1, p2) -> if otherE.Removed then None else Some (Utils.lineFromTwoPoints p1 p2))) &&
 124                            fg.Data.[y, x, 0] > 0uy
 125                         then
 126                             elements.[y-minY, x-minX] <- 1uy
 127                             nbElement <- nbElement + 1
 128                             sumCoords_y <- sumCoords_y + y
 129                             sumCoords_x <- sumCoords_x + x
 130
 131                             if infection.Data.[y, x, 0] > 0uy
 132                             then
 133                                 infectedPixels.Add(Point(x, y))
 134
 135                             if parasites.stain.Data.[y, x, 0] > 0uy
 136                             then
 137                                 stainPixels <- stainPixels + 1
 138                                 stain_x <- stain_x + (float x)
 139                                 stain_x2 <- stain_x2 + (float x) ** 2.0
 140                                 stain_y <- stain_y + (float y)
 141                                 stain_y2 <- stain_y2 + (float y) ** 2.0
 142
 143                             if parasites.darkStain.Data.[y, x, 0] > 0uy
 144                             then
 145                                 darkStainPixels <- darkStainPixels + 1
 146
 147                 let cellClass =
 148                     if float darkStainPixels > config.MaxDarkStainRatio * (float nbElement) (* ||
 149                         sqrt (((float sumCoords_x) / (float nbElement) - e.Cx) ** 2.0 + ((float sumCoords_y) / (float nbElement) - e.Cy) ** 2.0) > e.A * config.maxOffcenter *)
 150                     then
 151                         Peculiar
 152                     elif infectedPixels.Count > config.infectionPixelsRequired
 153                     then
 154                         let infectionToRemove = ImgTools.connectedComponents parasites.stain infectedPixels
 155                         for p in infectionToRemove do
 156                             infection.Data.[p.Y, p.X, 0] <- 0uy
 157                         InfectedRBC
 158                     else
 159                         HealthyRBC
 160
 161                 Some { cellClass = cellClass
 162                        center = Point(roundInt e.Cx, roundInt e.Cy)
 163                        elements = elements })