saveImg img filepath
+type Histogram = { data: int[]; total: int; sum: int; min: float32; max: float32 }
+
+let histogramImg (img: Image<Gray, float32>) (nbSamples: int) : Histogram =
+ let imgData = img.Data
+
+ let min, max =
+ let min = ref [| 0.0 |]
+ let minLocation = ref <| [| Point() |]
+ let max = ref [| 0.0 |]
+ let maxLocation = ref <| [| Point() |]
+ img.MinMax(min, max, minLocation, maxLocation)
+ float32 (!min).[0], float32 (!max).[0]
+
+ let bin (x: float32) : int =
+ let p = int ((x - min) / (max - min) * float32 nbSamples)
+ if p >= nbSamples then nbSamples - 1 else p
+
+ let data = Array.zeroCreate nbSamples
+
+ for i in 0 .. img.Height - 1 do
+ for j in 0 .. img.Width - 1 do
+ let p = bin imgData.[i, j, 0]
+ data.[p] <- data.[p] + 1
+
+ { data = data; total = img.Height * img.Width; sum = Array.sum data; min = min; max = max }
+
+let histogramMat (mat: Matrix<float32>) (nbSamples: int) : Histogram =
+ let matData = mat.Data
+
+ let min, max =
+ let min = ref 0.0
+ let minLocation = ref <| Point()
+ let max = ref 0.0
+ let maxLocation = ref <| Point()
+ mat.MinMax(min, max, minLocation, maxLocation)
+ float32 !min, float32 !max
+
+ let bin (x: float32) : int =
+ let p = int ((x - min) / (max - min) * float32 nbSamples)
+ if p >= nbSamples then nbSamples - 1 else p
+
+ let data = Array.zeroCreate nbSamples
+
+ for i in 0 .. mat.Height - 1 do
+ for j in 0 .. mat.Width - 1 do
+ let p = bin matData.[i, j]
+ data.[p] <- data.[p] + 1
+
+ { data = data; total = mat.Height * mat.Width; sum = Array.sum data; min = min; max = max }
+
+let histogram (values: float32 seq) (nbSamples: int) : Histogram =
+ let mutable min = Single.MaxValue
+ let mutable max = Single.MinValue
+ let mutable n = 0
+
+ for v in values do
+ n <- n + 1
+ if v < min then min <- v
+ if v > max then max <- v
+
+ let bin (x: float32) : int =
+ let p = int ((x - min) / (max - min) * float32 nbSamples)
+ if p >= nbSamples then nbSamples - 1 else p
+
+ let data = Array.zeroCreate nbSamples
+
+ for v in values do
+ let p = bin v
+ data.[p] <- data.[p] + 1
+
+ { data = data; total = n; sum = Array.sum data; min = min; max = max }
+
+let otsu (hist: Histogram) : float32 * float32 * float32 =
+ let mutable sumB = 0
+ let mutable wB = 0
+ let mutable maximum = 0.0
+ let mutable level = 0
+ let sum = hist.data |> Array.mapi (fun i v -> i * v) |> Array.sum |> float
+
+ for i in 0 .. hist.data.Length - 1 do
+ wB <- wB + hist.data.[i]
+ if wB <> 0
+ then
+ let wF = hist.total - wB
+ if wF <> 0
+ then
+ sumB <- sumB + i * hist.data.[i]
+ let mB = (float sumB) / (float wB)
+ let mF = (sum - float sumB) / (float wF)
+ let between = (float wB) * (float wF) * (mB - mF) ** 2.;
+ if between >= maximum
+ then
+ level <- i
+ maximum <- between
+
+ let mean1 =
+ let mutable sum = 0
+ let mutable nb = 0
+ for i in 0 .. level - 1 do
+ sum <- sum + i * hist.data.[i]
+ nb <- nb + hist.data.[i]
+ (sum + level * hist.data.[level] / 2) / (nb + hist.data.[level] / 2)
+
+ let mean2 =
+ let mutable sum = 0
+ let mutable nb = 0
+ for i in level + 1 .. hist.data.Length - 1 do
+ sum <- sum + i * hist.data.[i]
+ nb <- nb + hist.data.[i]
+ (sum + level * hist.data.[level] / 2) / (nb + hist.data.[level] / 2)
+
+ let toFloat l =
+ float32 l / float32 hist.data.Length * (hist.max - hist.min) + hist.min
+
+ toFloat level, toFloat mean1, toFloat mean2
+
+
let suppressMConnections (img: Matrix<byte>) =
let w = img.Width
let h = img.Height
let thresholdHigh, thresholdLow =
let sensibilityHigh = 0.1f
- let sensibilityLow = 0.1f
+ let sensibilityLow = 0.0f
use magnitudesByte = magnitudes.Convert<byte>()
- let threshold = float32 <| CvInvoke.Threshold(magnitudesByte, magnitudesByte, 0.0, 1.0, CvEnum.ThresholdType.Otsu ||| CvEnum.ThresholdType.Binary)
+ let threshold, _, _ = otsu (histogramMat magnitudes 300)
threshold + (sensibilityHigh * threshold), threshold - (sensibilityLow * threshold)
// Non-maximum suppression.
nextElements.Add(p) |> ignore
else
- let m' = pixels.[p.Y, p.X]
- if m' <> null
- then
+ match pixels.[p.Y, p.X] with
+ | null -> ()
+ | m' ->
if m'.Elements.Count + m.Elements.Count <= area
then
m'.State <- AreaState.Removed
member val Surface = 0 with get, set
-let private areaOperationF (img: Image<Gray, float32>) (area: int) (op: AreaOperation) =
+let private areaOperationF (img: Image<Gray, float32>) (areas: (int * 'a) list) (f: ('a -> float32 -> unit) option) (op: AreaOperation) =
let w = img.Width
let h = img.Height
let earth = img.Data
let ni = i + p.Y
let nj = j + p.X
let neighbor = Point(nj, ni)
- if ni >= 0 && ni < h && nj >= 0 && nj < w && ownership.[ni, nj] = null && not (shorePoints.Contains(neighbor))
+ if ni >= 0 && ni < h && nj >= 0 && nj < w && Object.ReferenceEquals(ownership.[ni, nj], null) && not (shorePoints.Contains(neighbor))
then
shorePoints.Add(neighbor) |> ignore
island.Shore.Add earth.[ni, nj, 0] neighbor
- for island in islands do
- let mutable stop = island.Shore.IsEmpty
-
- // 'true' if 'p' is owned or adjacent to 'island'.
- let ownedOrAdjacent (p: Point) : bool =
- ownership.[p.Y, p.X] = island ||
- (p.Y > 0 && ownership.[p.Y - 1, p.X] = island) ||
- (p.Y < h - 1 && ownership.[p.Y + 1, p.X] = island) ||
- (p.X > 0 && ownership.[p.Y, p.X - 1] = island) ||
- (p.X < w - 1 && ownership.[p.Y, p.X + 1] = island)
-
- while not stop && island.Surface < area do
- let level, next = island.Shore.Max
- let other = ownership.[next.Y, next.X]
- if other = island // During merging, some points on the shore may be owned by the island itself -> ignored.
- then
- island.Shore.RemoveNext ()
- else
- if other <> null
- then // We touching another island.
- if island.Surface + other.Surface >= area
- then
- stop <- true
- else // We can merge 'other' into 'surface'.
- island.Surface <- island.Surface + other.Surface
- island.Level <- if comparer.Compare(island.Level, other.Level) > 0 then island.Level else other.Level
- for l, p in other.Shore do
- let mutable currentY = p.Y + 1
- while currentY < h && ownership.[currentY, p.X] = other do
- ownership.[currentY, p.X] <- island
- currentY <- currentY + 1
- island.Shore.Add l p
- other.Shore.Clear()
-
- elif comparer.Compare(level, island.Level) > 0
+ for area, obj in areas do
+ for island in islands do
+ let mutable stop = island.Shore.IsEmpty
+
+ // 'true' if 'p' is owned or adjacent to 'island'.
+ let inline ownedOrAdjacent (p: Point) : bool =
+ ownership.[p.Y, p.X] = island ||
+ (p.Y > 0 && ownership.[p.Y - 1, p.X] = island) ||
+ (p.Y < h - 1 && ownership.[p.Y + 1, p.X] = island) ||
+ (p.X > 0 && ownership.[p.Y, p.X - 1] = island) ||
+ (p.X < w - 1 && ownership.[p.Y, p.X + 1] = island)
+
+ while not stop && island.Surface < area do
+ let level, next = island.Shore.Max
+ let other = ownership.[next.Y, next.X]
+ if other = island // During merging, some points on the shore may be owned by the island itself -> ignored.
then
- stop <- true
- else
island.Shore.RemoveNext ()
- for i, j in se do
- let ni = i + next.Y
- let nj = j + next.X
- if ni < 0 || ni >= h || nj < 0 || nj >= w
+ else
+ if not <| Object.ReferenceEquals(other, null)
+ then // We touching another island.
+ if island.Surface + other.Surface >= area
then
- island.Surface <- Int32.MaxValue
stop <- true
- else
- let neighbor = Point(nj, ni)
- if not <| ownedOrAdjacent neighbor
- then
- island.Shore.Add earth.[ni, nj, 0] neighbor
- if not stop
+ else // We can merge 'other' into 'surface'.
+ island.Surface <- island.Surface + other.Surface
+ island.Level <- if comparer.Compare(island.Level, other.Level) > 0 then island.Level else other.Level
+ for l, p in other.Shore do
+ let mutable currentY = p.Y + 1
+ while currentY < h && ownership.[currentY, p.X] = other do
+ ownership.[currentY, p.X] <- island
+ currentY <- currentY + 1
+ island.Shore.Add l p
+ other.Shore.Clear()
+
+ elif comparer.Compare(level, island.Level) > 0
then
- ownership.[next.Y, next.X] <- island
- island.Level <- level
- island.Surface <- island.Surface + 1
-
- for i in 0 .. h - 1 do
- for j in 0 .. w - 1 do
- let island = ownership.[i, j]
- if island <> null
- then
- earth.[i, j, 0] <- island.Level
+ stop <- true
+ else
+ island.Shore.RemoveNext ()
+ for i, j in se do
+ let ni = i + next.Y
+ let nj = j + next.X
+ if ni < 0 || ni >= h || nj < 0 || nj >= w
+ then
+ island.Surface <- Int32.MaxValue
+ stop <- true
+ else
+ let neighbor = Point(nj, ni)
+ if not <| ownedOrAdjacent neighbor
+ then
+ island.Shore.Add earth.[ni, nj, 0] neighbor
+ if not stop
+ then
+ ownership.[next.Y, next.X] <- island
+ island.Level <- level
+ island.Surface <- island.Surface + 1
+
+ let mutable diff = 0.f
+
+ for i in 0 .. h - 1 do
+ for j in 0 .. w - 1 do
+ match ownership.[i, j] with
+ | null -> ()
+ | island ->
+ let l = island.Level
+ diff <- diff + l - earth.[i, j, 0]
+ earth.[i, j, 0] <- l
+
+ match f with
+ | Some f' -> f' obj diff
+ | _ -> ()
()
let areaOpenF (img: Image<Gray, float32>) (area: int) =
- areaOperationF img area AreaOperation.Opening
+ areaOperationF img [ area, () ] None AreaOperation.Opening
let areaCloseF (img: Image<Gray, float32>) (area: int) =
- areaOperationF img area AreaOperation.Closing
+ areaOperationF img [ area, () ] None AreaOperation.Closing
+
+let areaOpenFWithFun (img: Image<Gray, float32>) (areas: (int * 'a) list) (f: 'a -> float32 -> unit) =
+ areaOperationF img areas (Some f) AreaOperation.Opening
+
+let areaCloseFWithFun (img: Image<Gray, float32>) (areas: (int * 'a) list) (f: 'a -> float32 -> unit) =
+ areaOperationF img areas (Some f) AreaOperation.Closing
// A simpler algorithm than 'areaOpen' but slower.
let areaOpen2 (img: Image<Gray, byte>) (area: int) =