Use k-means instead of k-medians.

[master-thesis.git] / Parasitemia / Parasitemia / KMeans.fs

diff --git a/Parasitemia/Parasitemia/KMeans.fs b/Parasitemia/Parasitemia/KMeans.fs
new file mode 100644 (file)
index 0000000..7c18120
--- /dev/null
+++ b/Parasitemia/Parasitemia/KMeans.fs
@@ -0,0 +1,57 @@
+module KMeans
+
+open System.Collections.Generic
+open System.Drawing
+
+open Emgu.CV
+open Emgu.CV.Structure
+
+type Result = {
+    fg: Image<Gray, byte>
+    mean_bg: float
+    mean_fg: float
+    d_fg: Image<Gray, float32> } // Euclidean distances of the foreground to mean_fg.
+
+let kmeans (img: Image<Gray, float32>) (fgFactor: float) : Result =
+    let nbIteration = 3
+    let w = img.Width
+    let h = img.Height
+
+    let min = ref [| 0.0 |]
+    let minLocation = ref <| [| Point() |]
+    let max = ref [| 0.0 |]
+    let maxLocation = ref <| [| Point() |]
+    img.MinMax(min, max, minLocation, maxLocation)
+
+    let mutable mean_bg = (!max).[0] - ((!max).[0] - (!min).[0]) / 4.0
+    let mutable mean_fg = (!min).[0] + ((!max).[0] - (!min).[0]) / 4.0
+    use mutable d_bg = new Image<Gray, float32>(img.Size)
+    let mutable d_fg = new Image<Gray, float32>(img.Size)
+    let mutable fg = new Image<Gray, byte>(img.Size)
+
+    for i in 1 .. nbIteration do
+        d_bg <- img.AbsDiff(Gray(mean_bg))
+        d_fg <- img.AbsDiff(Gray(mean_fg))
+
+        CvInvoke.Compare(d_fg, d_bg, fg, CvEnum.CmpType.LessThan)
+
+        let mutable bg_total = 0.0
+        let mutable bg_nb = 0
+
+        let mutable fg_total = 0.0
+        let mutable fg_nb = 0
+
+        for i in 0 .. h - 1 do
+            for j in 0 .. w - 1 do
+                if fg.Data.[i, j, 0] > 0uy
+                then
+                    fg_total <- fg_total + float img.Data.[i, j, 0]
+                    fg_nb <- fg_nb + 1
+                else
+                    bg_total <- bg_total + float img.Data.[i, j, 0]
+                    bg_nb <- bg_nb + 1
+
+        mean_bg <- bg_total / float bg_nb
+        mean_fg <- fg_total / float fg_nb
+
+    { fg = fg; mean_bg = mean_bg; mean_fg = mean_fg; d_fg = d_fg }
\ No newline at end of file