commit 58775bf6d49072902d9b171fe4e88332af50a22c
Author: Pavle Portic <pavle.portic@tilda.center>
Date:   Sat Apr 13 00:30:22 2019 +0200

    Initial commit

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..37aab56
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+*.jpg
+*.png
+lumetri
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..f4ec1e2
--- /dev/null
+++ b/main.go
@@ -0,0 +1,108 @@
+//
+// main.go
+// Copyright (C) 2019 pavle <pavle.portic@tilda.center>
+//
+// Distributed under terms of the BSD-3-Clause license.
+//
+
+package main
+
+import (
+	"fmt"
+	"image"
+	"image/color"
+	_ "image/jpeg"
+	"image/png"
+	"log"
+	// "math"
+	"os"
+	"time"
+)
+
+func elapsed() func() {
+	start := time.Now()
+	return func() {
+		fmt.Printf("%v\n", time.Since(start))
+	}
+}
+
+const width uint = 512
+
+func main() {
+	defer elapsed()()
+
+	imgfile, err := os.Open("in.jpg")
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer imgfile.Close()
+
+	img, _, err := image.Decode(imgfile)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	bounds := img.Bounds()
+	scale := float64(width) / float64(bounds.Max.X - bounds.Min.X)
+	coeff := uint8(scale * 4)
+	if coeff == 0 {
+		coeff = 1
+	}
+	fmt.Printf("scale: %v, coeff: %v\n", scale, coeff)
+
+	scope := image.NewRGBA(image.Rect(0, 0, int(width), 256))
+	scope_bounds := scope.Bounds()
+
+	for y := scope_bounds.Min.Y; y < scope_bounds.Max.Y; y++ {
+		for x := scope_bounds.Min.X; x < scope_bounds.Max.X; x++ {
+			scope.SetRGBA(x, y, color.RGBA{0, 0, 0, 255})
+		}
+	}
+
+	for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
+		for x := bounds.Min.X; x < bounds.Max.X; x++ {
+			r, g, b, _:= img.At(x, y).RGBA()
+			ir := uint8(r >> 8)
+			ig := uint8(g >> 8)
+			ib := uint8(b >> 8)
+
+			tr, tg, tb, _ := scope.At(int(float64(x) * scale), 255 - int(ir)).RGBA()
+			sr := uint8(tr >> 8)
+			sg := uint8(tg >> 8)
+			sb := uint8(tb >> 8)
+			if sr > 255 - coeff {
+				sr = 255
+			} else {
+				sr += coeff
+			}
+			scope.SetRGBA(int(float64(x) * scale), 255 - int(ir), color.RGBA{sr, sg, sb, 255})
+
+			tr, tg, tb, _ = scope.At(int(float64(x) * scale), 255 - int(ig)).RGBA()
+			sr = uint8(tr >> 8)
+			sg = uint8(tg >> 8)
+			sb = uint8(tb >> 8)
+			if sg > 255 - coeff {
+				sg = 255
+			} else {
+				sg += coeff
+			}
+			scope.SetRGBA(int(float64(x) * scale), 255 - int(ig), color.RGBA{sr, sg, sb, 255})
+
+			tr, tg, tb, _ = scope.At(int(float64(x) * scale), 255 - int(ib)).RGBA()
+			sr = uint8(tr >> 8)
+			sg = uint8(tg >> 8)
+			sb = uint8(tb >> 8)
+			if sb > 255 - coeff {
+				sb = 255
+			} else {
+				sb += coeff
+			}
+			scope.SetRGBA(int(float64(x) * scale), 255 - int(ib), color.RGBA{sr, sg, sb, 255})
+		}
+	}
+
+	outFile, _ := os.Create("output.png")
+	defer outFile.Close()
+	png.Encode(outFile, scope)
+}
+