Added ThresholdFilter

Author: jphsd

cmd/thresh.go

@@ -0,0 +1,30 @@
+//go:build ignore
+
+package main
+
+import (
+	"flag"
+	"github.com/jphsd/graphics2d/image"
+	"github.com/jphsd/texture"
+)
+
+func main() {
+	vv := flag.Float64("v", 0, "threshold")
+	flag.Parse()
+	v := *vv
+	name := flag.Args()[0]
+
+	img, err := image.ReadImage(name)
+	if err != nil {
+		panic(err)
+	}
+
+	width, height := img.Bounds().Dx(), img.Bounds().Dy()
+
+	cf := texture.NewImage(img, texture.LinearInterp)
+	f2 := texture.NewColorToGray(cf)
+	vf := texture.NewThresholdFilter(f2, v, -1, 1)
+	img2 := texture.NewTextureGray16(width, height, vf, 0, 0, 1, 1, false)
+
+	image.SaveImage(img2, "thresh")
+}