From 7482157a03ed3e9d7f45e54a126b391001f34948 Mon Sep 17 00:00:00 2001
From: Nick White <git@njw.name>
Date: Tue, 8 Oct 2019 12:52:33 +0100
Subject: Separate out bookpipeline from catch-all go.git repo, and rename to
 rescribe.xyz/bookpipeline

The dependencies from the go.git repo will follow in due course.
---
 preproc/wipesides.go | 160 ---------------------------------------------------
 1 file changed, 160 deletions(-)
 delete mode 100644 preproc/wipesides.go

(limited to 'preproc/wipesides.go')

diff --git a/preproc/wipesides.go b/preproc/wipesides.go
deleted file mode 100644
index 3d08053..0000000
--- a/preproc/wipesides.go
+++ /dev/null
@@ -1,160 +0,0 @@
-package preproc
-
-// TODO: add minimum size variable (default ~30%?)
-// TODO: switch to an interface rather than integralimg.I
-
-import (
-	"errors"
-	"fmt"
-	"image"
-	"image/color"
-	"image/draw"
-	_ "image/jpeg"
-	"image/png"
-	"os"
-
-	"rescribe.xyz/go.git/integralimg"
-)
-
-// returns the proportion of the given window that is black pixels
-func proportion(i integralimg.I, x int, size int) float64 {
-	w := i.GetVerticalWindow(x, size)
-	return w.Proportion()
-}
-
-// findbestedge goes through every vertical line from x to x+w to
-// find the one with the lowest proportion of black pixels.
-func findbestedge(img integralimg.I, 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
-}
-
-// findedges finds the edges of the main content, by moving a window of wsize
-// from near the middle of the image to the left and right, stopping when it reaches
-// a point at which there is a lower proportion of black pixels than thresh.
-func findedges(img integralimg.I, wsize int, thresh float64) (int, int) {
-	maxx := len(img[0]) - 1
-	var lowedge, highedge int = 0, maxx
-
-	// don't start at the middle, as this will fail for 2 column layouts,
-	// start 10% left or right of the middle
-	notcentre := maxx / 10
-
-	for x := maxx/2 + notcentre; x < maxx-wsize; x++ {
-		if proportion(img, x, wsize) <= thresh {
-			highedge = findbestedge(img, x, wsize)
-			break
-		}
-	}
-
-	for x := maxx/2 - notcentre; x > 0; x-- {
-		if proportion(img, x, wsize) <= thresh {
-			lowedge = findbestedge(img, x, wsize)
-			break
-		}
-	}
-
-	return lowedge, highedge
-}
-
-// wipesides fills the sections of image not within the boundaries
-// of lowedge and highedge with white
-func wipesides(img *image.Gray, lowedge int, highedge int) *image.Gray {
-	b := img.Bounds()
-	new := image.NewGray(b)
-
-	// set left edge white
-	for x := b.Min.X; x < lowedge; x++ {
-		for y := b.Min.Y; y < b.Max.Y; y++ {
-			new.SetGray(x, y, color.Gray{255})
-		}
-	}
-	// copy middle
-	for x := lowedge; x < highedge; x++ {
-		for y := b.Min.Y; y < b.Max.Y; y++ {
-			new.SetGray(x, y, img.GrayAt(x, y))
-		}
-	}
-	// set right edge white
-	for x := highedge; x < b.Max.X; x++ {
-		for y := b.Min.Y; y < b.Max.Y; y++ {
-			new.SetGray(x, y, color.Gray{255})
-		}
-	}
-
-	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, 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)
-}
-
-// WipeFile wipes an image file, filling the sections of the image
-// which fall outside the content area with white, providing the
-// content area is above min %.
-// inPath: path of the input image.
-// outPath: path to save the output image.
-// wsize: window size for wipe algorithm.
-// thresh: threshold for wipe algorithm.
-// min: minimum % of content area width to consider valid.
-func WipeFile(inPath string, outPath string, wsize int, thresh float64, min int) error {
-	f, err := os.Open(inPath)
-	defer f.Close()
-	if err != nil {
-		return errors.New(fmt.Sprintf("Could not open file %s: %v", inPath, err))
-	}
-	img, _, err := image.Decode(f)
-	if err != nil {
-		return errors.New(fmt.Sprintf("Could not decode image: %v", err))
-	}
-	b := img.Bounds()
-	gray := image.NewGray(image.Rect(0, 0, b.Dx(), b.Dy()))
-	draw.Draw(gray, b, img, b.Min, draw.Src)
-
-	clean := Wipe(gray, wsize, thresh, min)
-
-	f, err = os.Create(outPath)
-	if err != nil {
-		return errors.New(fmt.Sprintf("Could not create file %s: %v", outPath, err))
-	}
-	defer f.Close()
-	err = png.Encode(f, clean)
-	if err != nil {
-		return errors.New(fmt.Sprintf("Could not encode image: %v", err))
-	}
-	return nil
-}
-- 
cgit v1.2.1-24-ge1ad