From 787d63fc5d13c6250bd33da5a8e1eadbe86188cd Mon Sep 17 00:00:00 2001 From: Nick White Date: Tue, 8 Oct 2019 15:37:07 +0100 Subject: Continue separating the repository; remove all but preproc, and move integralimg package under it --- cmd/preproc/main.go | 90 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 90 insertions(+) create mode 100644 cmd/preproc/main.go (limited to 'cmd/preproc') diff --git a/cmd/preproc/main.go b/cmd/preproc/main.go new file mode 100644 index 0000000..5d71a62 --- /dev/null +++ b/cmd/preproc/main.go @@ -0,0 +1,90 @@ +package main + +// TODO: come up with a way to set a good ksize automatically + +import ( + "flag" + "fmt" + "image" + "image/draw" + _ "image/jpeg" + "image/png" + "log" + "os" + + "rescribe.xyz/preproc" +) + +// 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: preproc [-bt bintype] [-bw winsize] [-k num] [-m minperc] [-nowipe] [-wt wipethresh] [-ws wipesize] inimg outimg\n") + fmt.Fprintf(os.Stderr, "Binarize and preprocess an image\n") + flag.PrintDefaults() + } + binwsize := flag.Int("bw", 0, "Window size for sauvola binarization algorithm. Set automatically based on resolution if not set.") + ksize := flag.Float64("k", 0.5, "K for sauvola binarization algorithm. This controls the overall threshold level. Set it lower for very light text (try 0.1 or 0.2).") + btype := flag.String("bt", "binary", "Type of binarization threshold. binary or zeroinv are currently implemented.") + min := flag.Int("m", 30, "Minimum percentage of the image width for the content width calculation to be considered valid.") + nowipe := flag.Bool("nowipe", false, "Disable wiping completely.") + wipewsize := flag.Int("ws", 5, "Window size for wiping algorithm.") + thresh := flag.Float64("wt", 0.05, "Threshold for the wiping algorithm to determine the proportion of black pixels below which a window is determined to be the edge.") + 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 *binwsize == 0 { + *binwsize = autowsize(b) + } + + if *binwsize%2 == 0 { + *binwsize++ + } + + log.Print("Binarising") + var clean, threshimg image.Image + threshimg = preproc.IntegralSauvola(gray, *ksize, *binwsize) + + if *btype == "zeroinv" { + threshimg, err = preproc.BinToZeroInv(threshimg.(*image.Gray), img.(*image.RGBA)) + if err != nil { + log.Fatal(err) + } + } + + if !*nowipe { + log.Print("Wiping sides") + clean = preproc.Wipe(threshimg.(*image.Gray), *wipewsize, *thresh, *min) + } else { + clean = threshimg + } + + 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, clean) + if err != nil { + log.Fatalf("Could not encode image: %v\n", err) + } +} -- cgit v1.2.1-24-ge1ad