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authorNick White <git@njw.name>2019-05-13 17:28:38 +0100
committerNick White <git@njw.name>2019-05-13 17:28:38 +0100
commit6b7cc0cd671db9c8ff89eea1686099c48dba412a (patch)
tree3a184a9c893be8e097e17a1acc1cd9d80e1474be /cleanup/main.go
parentb2f127e33f92d778c9a4700ea5c97ba6fb20fe4a (diff)
Make cleanup a basic library
Diffstat (limited to 'cleanup/main.go')
-rw-r--r--cleanup/main.go175
1 files changed, 0 insertions, 175 deletions
diff --git a/cleanup/main.go b/cleanup/main.go
deleted file mode 100644
index fdec6e9..0000000
--- a/cleanup/main.go
+++ /dev/null
@@ -1,175 +0,0 @@
-package main
-
-// TODO: add minimum size variable (default ~30%?)
-// TODO: make into a small library
-// TODO: have the integral image specific stuff done by interface functions
-
-import (
- "flag"
- "fmt"
- "image"
- "image/color"
- "image/draw"
- _ "image/jpeg"
- "image/png"
- "log"
- "os"
-
- "rescribe.xyz/go.git/binarize"
-)
-
-type windowslice struct {
- topleft uint64
- topright uint64
- bottomleft uint64
- bottomright uint64
-}
-
-func getwindowslice(i [][]uint64, x int, size int) windowslice {
- maxy := len(i) - 1
- maxx := x + size
- if maxx > len(i[0])-1 {
- maxx = len(i[0]) - 1
- }
-
- return windowslice{i[0][x], i[0][maxx], i[maxy][x], i[maxy][maxx]}
-}
-
-// checkwindow checks the window from x to see whether more than
-// thresh proportion of the pixels are white, if so it returns true.
-func checkwindow(integral [][]uint64, x int, size int, thresh float64) bool {
- height := len(integral)
- window := getwindowslice(integral, x, size)
- // divide by 255 as each on pixel has the value of 255
- sum := (window.bottomright + window.topleft - window.topright - window.bottomleft) / 255
- area := size * height
- proportion := float64(area)/float64(sum) - 1
- return proportion <= thresh
-}
-
-// returns the proportion of the given window that is black pixels
-func proportion(integral [][]uint64, x int, size int) float64 {
- height := len(integral)
- window := getwindowslice(integral, x, size)
- // divide by 255 as each on pixel has the value of 255
- sum := (window.bottomright + window.topleft - window.topright - window.bottomleft) / 255
- area := size * height
- return float64(area)/float64(sum) - 1
-}
-
-// 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
-}
-
-// findbestedge goes through every vertical line from x to x+w to
-// find the one with the lowest proportion of black pixels.
-func findbestedge(integral [][]uint64, 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(integral, 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 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(integral [][]uint64, wsize int, thresh float64) (int, int) {
- maxx := len(integral[0]) - 1
- var lowedge, highedge int = 0, maxx
-
- for x := maxx / 2; x < maxx-wsize; x++ {
- if checkwindow(integral, x, wsize, thresh) {
- highedge = findbestedge(integral, x, wsize)
- break
- }
- }
-
- for x := maxx / 2; x > 0; x-- {
- if checkwindow(integral, x, wsize, thresh) {
- lowedge = findbestedge(integral, x, wsize)
- break
- }
- }
-
- return lowedge, highedge
-}
-
-func main() {
- flag.Usage = func() {
- fmt.Fprintf(os.Stderr, "Usage: cleanup [-t thresh] [-w winsize] inimg outimg\n")
- flag.PrintDefaults()
- }
- wsize := flag.Int("w", 5, "Window size for mask finding algorithm.")
- thresh := flag.Float64("t", 0.05, "Threshold for 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)
-
- integral := binarize.Integralimg(gray)
-
- lowedge, highedge := findedges(integral, *wsize, *thresh)
-
- clean := wipesides(gray, lowedge, highedge)
-
- 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)
- }
-}