Initial data commit

Task/Hough-transform/Go/hough-transform.go

@@ -0,0 +1,71 @@
+package main
+
+import (
+    "fmt"
+    "image"
+    "image/color"
+    "image/draw"
+    "image/png"
+    "math"
+    "os"
+)
+
+func hough(im image.Image, ntx, mry int) draw.Image {
+    nimx := im.Bounds().Max.X
+    mimy := im.Bounds().Max.Y
+
+    him := image.NewGray(image.Rect(0, 0, ntx, mry))
+    draw.Draw(him, him.Bounds(), image.NewUniform(color.White),
+        image.Point{}, draw.Src)
+
+    rmax := math.Hypot(float64(nimx), float64(mimy))
+    dr := rmax / float64(mry/2)
+    dth := math.Pi / float64(ntx)
+
+    for jx := 0; jx < nimx; jx++ {
+        for iy := 0; iy < mimy; iy++ {
+            col := color.GrayModel.Convert(im.At(jx, iy)).(color.Gray)
+            if col.Y == 255 {
+                continue
+            }
+            for jtx := 0; jtx < ntx; jtx++ {
+                th := dth * float64(jtx)
+                r := float64(jx)*math.Cos(th) + float64(iy)*math.Sin(th)
+                iry := mry/2 - int(math.Floor(r/dr+.5))
+                col = him.At(jtx, iry).(color.Gray)
+                if col.Y > 0 {
+                    col.Y--
+                    him.SetGray(jtx, iry, col)
+                }
+            }
+        }
+    }
+    return him
+}
+
+func main() {
+    f, err := os.Open("Pentagon.png")
+    if err != nil {
+        fmt.Println(err)
+        return
+    }
+    pent, err := png.Decode(f)
+    if err != nil {
+        fmt.Println(err)
+        return
+    }
+    if err = f.Close(); err != nil {
+        fmt.Println(err)
+    }
+    h := hough(pent, 460, 360)
+    if f, err = os.Create("hough.png"); err != nil {
+        fmt.Println(err)
+        return
+    }
+    if err = png.Encode(f, h); err != nil {
+        fmt.Println(err)
+    }
+    if cErr := f.Close(); cErr != nil && err == nil {
+        fmt.Println(err)
+    }
+}