diff options
author | Nick White <git@njw.name> | 2019-07-25 17:53:26 +0100 |
---|---|---|
committer | Nick White <git@njw.name> | 2019-07-25 17:53:26 +0100 |
commit | ab773582e72bf01e1cad71431d2ddea5f216cc07 (patch) | |
tree | 849b43a0855f81b813a3fd396e5c5edc2a8ba71f /preproc/preprocmulti.go | |
parent | 56687b56558ced34b35955163bd5dd3697d578e8 (diff) |
Add first draft of pipelinepreprocess - completely untested, will contain bugs
Diffstat (limited to 'preproc/preprocmulti.go')
-rw-r--r-- | preproc/preprocmulti.go | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/preproc/preprocmulti.go b/preproc/preprocmulti.go new file mode 100644 index 0000000..cd7ad34 --- /dev/null +++ b/preproc/preprocmulti.go @@ -0,0 +1,93 @@ +package preproc + +// TODO: come up with a way to set a good ksize automatically + +import ( + "fmt" + "image" + "image/draw" + _ "image/jpeg" + "image/png" + "os" + "strings" + + "rescribe.xyz/go.git/integralimg" +) + +// TODO: do more testing to see how good this assumption is +func autowsize(bounds image.Rectangle) int { + return bounds.Dx() / 60 +} + +// PreProcMulti binarizes and preprocesses an image with multiple binarisation levels. +// inPath: Path of input image. +// ksizes: Slice of k values to pass to Sauvola algorithm +// binType: Type of binarization threshold. binary or zeroinv are currently implemented. +// binWsize: Window size for sauvola binarization algorithm. Set automatically based on resolution if 0. +// wipe: Whether to wipe (clear sides) the image +// wipeWsize: Window size for wiping algorithm +// wipeMinWidthPerc: Minimum percentage of the image width for the content width calculation to be considered valid +// Note: copied from cmd/preprocmulti/main.go, should think about the best way +// to organise this code later. +// TODO: return errors that encapsulate the err describing where it was encountered +func PreProcMulti(inPath string, ksizes []float64, binType string, binWsize int, wipe bool, wipeWsize int, wipeMinWidthPerc int) ([]string, error) { + // Make outBase inPath up to final . + s := strings.Split(inPath, ".") + outBase := strings.Join(s[:len(s)-1], "") + + var donePaths []string + + f, err := os.Open(inPath) + if err != nil { + return donePaths, err + } + defer f.Close() + img, _, err := image.Decode(f) + if err != nil { + return donePaths, 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++ + } + + var clean, threshimg image.Image + integrals := integralimg.ToAllIntegralImg(gray) + + for _, k := range ksizes { + threshimg = PreCalcedSauvola(integrals, gray, k, binWsize) + + if binType == "zeroinv" { + threshimg, err = BinToZeroInv(threshimg.(*image.Gray), img.(*image.RGBA)) + if err != nil { + return donePaths, err + } + } + + if wipe { + clean = Wipe(threshimg.(*image.Gray), wipeWsize, k * 0.02, wipeMinWidthPerc) + } else { + clean = threshimg + } + + savefn := fmt.Sprintf("%s_bin%0.1f.png", outBase, k) + f, err = os.Create(savefn) + if err != nil { + return donePaths, err + } + defer f.Close() + err = png.Encode(f, clean) + if err != nil { + return donePaths, err + } + donePaths = append(donePaths, savefn) + } + return donePaths, nil +} |