diff options
| -rw-r--r-- | preproc/cmd/preproc/main.go | 6 | ||||
| -rw-r--r-- | preproc/cmd/preprocmulti/main.go | 6 | ||||
| -rw-r--r-- | preproc/cmd/wipe/main.go | 9 | ||||
| -rw-r--r-- | preproc/wipesides.go | 19 |
4 files changed, 27 insertions, 13 deletions
diff --git a/preproc/cmd/preproc/main.go b/preproc/cmd/preproc/main.go index 053de8f..d8d5b66 100644 --- a/preproc/cmd/preproc/main.go +++ b/preproc/cmd/preproc/main.go @@ -1,7 +1,6 @@ package main // TODO: come up with a way to set a good ksize automatically -// TODO: add minimum size variable (default ~30%?) for wipe import ( "flag" @@ -23,13 +22,14 @@ func autowsize(bounds image.Rectangle) int { func main() { flag.Usage = func() { - fmt.Fprintf(os.Stderr, "Usage: preproc [-bt bintype] [-bw winsize] [-k num] [-wt wipethresh] [-ws wipesize] inimg outimg\n") + fmt.Fprintf(os.Stderr, "Usage: preproc [-bt bintype] [-bw winsize] [-k num] [-m minperc] [-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.") 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() @@ -71,7 +71,7 @@ func main() { } log.Print("Wiping sides") - clean := preproc.Wipe(threshimg.(*image.Gray), *wipewsize, *thresh) + clean := preproc.Wipe(threshimg.(*image.Gray), *wipewsize, *thresh, *min) f, err = os.Create(flag.Arg(1)) if err != nil { diff --git a/preproc/cmd/preprocmulti/main.go b/preproc/cmd/preprocmulti/main.go index eea7ab4..947625e 100644 --- a/preproc/cmd/preprocmulti/main.go +++ b/preproc/cmd/preprocmulti/main.go @@ -1,7 +1,6 @@ package main // TODO: come up with a way to set a good ksize automatically -// TODO: add minimum size variable (default ~30%?) for wipe import ( "flag" @@ -26,7 +25,7 @@ func main() { ksizes := []float64{0.2, 0.3, 0.4, 0.5, 0.6} flag.Usage = func() { - fmt.Fprintf(os.Stderr, "Usage: preproc [-bt bintype] [-bw winsize] [-wt wipethresh] [-ws wipesize] inimg outbase\n") + fmt.Fprintf(os.Stderr, "Usage: preproc [-bt bintype] [-bw winsize] [-m minperc] [-wt wipethresh] [-ws wipesize] inimg outbase\n") fmt.Fprintf(os.Stderr, "Binarize and preprocess an image, with multiple binarisation levels,\n") fmt.Fprintf(os.Stderr, "saving images to outbase_bin{k}.png.\n") fmt.Fprintf(os.Stderr, "Binarises with these levels for k: %v.\n", ksizes) @@ -34,6 +33,7 @@ func main() { } binwsize := flag.Int("bw", 0, "Window size for sauvola binarization algorithm. Set automatically based on resolution if not set.") 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.") 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() @@ -80,7 +80,7 @@ func main() { } log.Print("Wiping sides") - clean := preproc.Wipe(threshimg.(*image.Gray), *wipewsize, *thresh) + clean := preproc.Wipe(threshimg.(*image.Gray), *wipewsize, *thresh, *min) savefn := fmt.Sprintf("%s_bin%0.1f.png", flag.Arg(1), k) log.Printf("Saving %s\n", savefn) diff --git a/preproc/cmd/wipe/main.go b/preproc/cmd/wipe/main.go index e735a0a..ceff2e7 100644 --- a/preproc/cmd/wipe/main.go +++ b/preproc/cmd/wipe/main.go @@ -1,7 +1,5 @@ package main -// TODO: add minimum size variable (default ~30%?) - import ( "flag" "fmt" @@ -17,12 +15,13 @@ import ( func main() { flag.Usage = func() { - fmt.Fprintf(os.Stderr, "Usage: wipe [-t thresh] [-w winsize] inimg outimg\n") + fmt.Fprintf(os.Stderr, "Usage: wipe [-m minperc] [-t thresh] [-w winsize] inimg outimg\n") fmt.Fprintf(os.Stderr, "Wipes the sections of an image which are outside the content area.\n") flag.PrintDefaults() } - wsize := flag.Int("w", 5, "Window size for mask finding algorithm.") + min := flag.Int("m", 30, "Minimum percentage of the image width for the content width calculation to be considered valid.") thresh := flag.Float64("t", 0.05, "Threshold for the proportion of black pixels below which a window is determined to be the edge.") + wsize := flag.Int("w", 5, "Window size for mask finding algorithm.") flag.Parse() if flag.NArg() < 2 { flag.Usage() @@ -42,7 +41,7 @@ func main() { gray := image.NewGray(image.Rect(0, 0, b.Dx(), b.Dy())) draw.Draw(gray, b, img, b.Min, draw.Src) - clean := preproc.Wipe(gray, *wsize, *thresh) + clean := preproc.Wipe(gray, *wsize, *thresh, *min) f, err = os.Create(flag.Arg(1)) if err != nil { diff --git a/preproc/wipesides.go b/preproc/wipesides.go index 04bfa11..9b8387a 100644 --- a/preproc/wipesides.go +++ b/preproc/wipesides.go @@ -90,10 +90,25 @@ func wipesides(img *image.Gray, lowedge int, highedge int) *image.Gray { return new } +// toonarrow checks whether the area between lowedge and highedge is +// less than min % of the total image width +func toonarrow(img *image.Gray, lowedge int, highedge int, min int) bool { + b := img.Bounds() + imgw := b.Max.X - b.Min.X + wipew := highedge - lowedge + if float64(wipew) / float64(imgw) * 100 < float64(min) { + return true + } + return false +} + // wipe fills the sections of image which fall outside the content -// area with white -func Wipe(img *image.Gray, wsize int, thresh float64) *image.Gray { +// area with white, providing the content area is above min % +func Wipe(img *image.Gray, wsize int, thresh float64, min int) *image.Gray { integral := integralimg.ToIntegralImg(img) lowedge, highedge := findedges(integral, wsize, thresh) + if toonarrow(img, lowedge, highedge, min) { + return img + } return wipesides(img, lowedge, highedge) } |