From f20982f465ee4735caf5b0ebc3c57af31ee90e75 Mon Sep 17 00:00:00 2001 From: Nick White Date: Tue, 26 Mar 2019 15:43:21 +0000 Subject: Move sauvola binarization tool to cmd/binarize --- binarize/cmd/binarize/main.go | 69 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 69 insertions(+) create mode 100644 binarize/cmd/binarize/main.go (limited to 'binarize/cmd') diff --git a/binarize/cmd/binarize/main.go b/binarize/cmd/binarize/main.go new file mode 100644 index 0000000..c4b9562 --- /dev/null +++ b/binarize/cmd/binarize/main.go @@ -0,0 +1,69 @@ +package main + +import ( + "flag" + "fmt" + "image" + "image/draw" + _ "image/jpeg" + "image/png" + "log" + "os" + + "rescribe.xyz/go.git/binarize" +) + +// TODO: do more testing to see how good this assumption is +func autowsize(bounds image.Rectangle) int { + return bounds.Dx() / 60 +} + +func main() { + flag.Usage = func() { + fmt.Fprintf(os.Stderr, "Usage: sauvola [-w num] [-k num] inimg outimg\n") + flag.PrintDefaults() + } + wsize := flag.Int("w", 0, "Window size for sauvola algorithm. Set automatically based on resolution if not set.") + ksize := flag.Float64("k", 0.5, "K for sauvola algorithm. This controls the overall threshold level. Set it lower for very light text (try 0.1 or 0.2).") + flag.Parse() + if flag.NArg() < 2 { + flag.Usage() + os.Exit(1) + } + + f, err := os.Open(flag.Arg(0)) + defer f.Close() + if err != nil { + log.Fatalf("Could not open file %s: %v\n", flag.Arg(0), err) + } + img, _, err := image.Decode(f) + if err != nil { + log.Fatalf("Could not decode image: %v\n", err) + } + b := img.Bounds() + gray := image.NewGray(image.Rect(0, 0, b.Dx(), b.Dy())) + draw.Draw(gray, b, img, b.Min, draw.Src) + + if *wsize == 0 { + *wsize = autowsize(b) + log.Printf("Set window size to %d\n", *wsize) + } + + if *wsize % 2 == 0 { + *wsize++ + } + + // TODO: come up with a way to set a good ksize automatically + + thresh := binarize.IntegralSauvola(gray, *ksize, *wsize) + + f, err = os.Create(flag.Arg(1)) + if err != nil { + log.Fatalf("Could not create file %s: %v\n", flag.Arg(1), err) + } + defer f.Close() + err = png.Encode(f, thresh) + if err != nil { + log.Fatalf("Could not encode image: %v\n", err) + } +} -- cgit v1.2.1-24-ge1ad