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Diffstat (limited to 'cmd/splittable/main.go')
-rw-r--r-- | cmd/splittable/main.go | 146 |
1 files changed, 0 insertions, 146 deletions
diff --git a/cmd/splittable/main.go b/cmd/splittable/main.go deleted file mode 100644 index 3fc5ace..0000000 --- a/cmd/splittable/main.go +++ /dev/null @@ -1,146 +0,0 @@ -// Copyright 2020 Nick White. -// Use of this source code is governed by the GPLv3 -// license that can be found in the LICENSE file. - -// splittable is an experimental program to split a table into -// individual cells suitable for OCR -package main - -import ( - "flag" - "fmt" - "image" - "image/draw" - _ "image/jpeg" - "image/png" - "log" - "os" - - "rescribe.xyz/integralimg" -) - -const usage = `Usage: splittable [-t thresh] [-w winsize] inimg outbase - -splittable is an experimental program to split a table into individual -cells suitable for OCR. It does this by detecting lines. At present it -just detects vertical lines and outputs images for each section -between those lines. - -` - -// returns the proportion of the given window that is black pixels -func proportion(i integralimg.Image, x int, size int) float64 { - w := i.GetVerticalWindow(x, size) - return w.Proportion() -} - -// findbestvline goes through every vertical line from x to x+w to -// find the one with the lowest proportion of black pixels. -func findbestvline(img integralimg.Image, x int, w int) int { - var bestx int - var best float64 - - if w == 1 { - return x - } - - right := x + w - for ; x < right; x++ { - prop := proportion(img, x, 1) - if prop > best { - best = prop - bestx = x - } - } - - return bestx -} - -// findvlines finds vertical lines, returning an array of x coordinates -// for each line. It works by moving a window of wsize across the image, -// marking each place where there is a higher proportion of black pixels -// than thresh. -func findvlines(img integralimg.Image, wsize int, thresh float64) []int { - maxx := img.Bounds().Dx() - 1 - var lines []int - - for x := 0; x < maxx-wsize; x+=wsize { - if proportion(img, x, wsize) >= thresh { - l := findbestvline(img, x, wsize) - lines = append(lines, l) - } - } - - return lines -} - -func drawsection(img *image.Gray, x1 int, x2 int) *image.Gray { - b := img.Bounds() - width := x2-x1 - new := image.NewGray(image.Rect(0, b.Min.Y, width, b.Max.Y)) - - for x := 0; x < width; x++ { - for y := b.Min.Y; y < b.Max.Y; y++ { - new.SetGray(x, y, img.GrayAt(x1 + x, y)) - } - } - - return new -} - -func main() { - flag.Usage = func() { - fmt.Fprintf(flag.CommandLine.Output(), usage) - flag.PrintDefaults() - } - thresh := flag.Float64("t", 0.85, "Threshold for the proportion of black pixels below which a window is determined to be a line. Higher means fewer lines will be found.") - wsize := flag.Int("w", 1, "Window size for mask finding algorithm.") - 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) - - integral := integralimg.NewImage(b) - draw.Draw(integral, b, gray, b.Min, draw.Src) - vlines := findvlines(*integral, *wsize, *thresh) - - for i, v := range vlines { - fmt.Printf("line detected at x=%d\n", v) - - if i+1 >= len(vlines) { - break - } - section := drawsection(gray, v, vlines[i+1]) - - fn := fmt.Sprintf("%s-%d.png", flag.Arg(1), v) - f, err = os.Create(fn) - if err != nil { - log.Fatalf("Could not create file %s: %v\n", fn, err) - } - defer f.Close() - err := png.Encode(f, section) - if err != nil { - log.Fatalf("Could not encode image %s: %v\n", fn, err) - } - } - - - // TODO: find horizontal lines too - // TODO: do rotation - // TODO: output table cells - // TODO: potentially send cells straight to tesseract -} |