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.
---
integralimg/integralimg.go | 169 ---------------------------------------------
1 file changed, 169 deletions(-)
delete mode 100644 integralimg/integralimg.go
(limited to 'integralimg')
diff --git a/integralimg/integralimg.go b/integralimg/integralimg.go
deleted file mode 100644
index 406ed61..0000000
--- a/integralimg/integralimg.go
+++ /dev/null
@@ -1,169 +0,0 @@
-package integralimg
-
-import (
- "image"
- "math"
-)
-
-// I is the Integral Image
-type I [][]uint64
-
-// Sq contains an Integral Image and its Square
-type WithSq struct {
- Img I
- Sq I
-}
-
-// Window is a part of an Integral Image
-type Window struct {
- topleft uint64
- topright uint64
- bottomleft uint64
- bottomright uint64
- width int
- height int
-}
-
-// ToIntegralImg creates an integral image
-func ToIntegralImg(img *image.Gray) I {
- var integral I
- var oldy, oldx, oldxy uint64
- b := img.Bounds()
- for y := b.Min.Y; y < b.Max.Y; y++ {
- newrow := []uint64{}
- for x := b.Min.X; x < b.Max.X; x++ {
- oldx, oldy, oldxy = 0, 0, 0
- if x > 0 {
- oldx = newrow[x-1]
- }
- if y > 0 {
- oldy = integral[y-1][x]
- }
- if x > 0 && y > 0 {
- oldxy = integral[y-1][x-1]
- }
- pixel := uint64(img.GrayAt(x, y).Y)
- i := pixel + oldx + oldy - oldxy
- newrow = append(newrow, i)
- }
- integral = append(integral, newrow)
- }
- return integral
-}
-
-// ToSqIntegralImg creates an integral image of the square of all
-// pixel values
-func ToSqIntegralImg(img *image.Gray) I {
- var integral I
- var oldy, oldx, oldxy uint64
- b := img.Bounds()
- for y := b.Min.Y; y < b.Max.Y; y++ {
- newrow := []uint64{}
- for x := b.Min.X; x < b.Max.X; x++ {
- oldx, oldy, oldxy = 0, 0, 0
- if x > 0 {
- oldx = newrow[x-1]
- }
- if y > 0 {
- oldy = integral[y-1][x]
- }
- if x > 0 && y > 0 {
- oldxy = integral[y-1][x-1]
- }
- pixel := uint64(img.GrayAt(x, y).Y)
- i := pixel * pixel + oldx + oldy - oldxy
- newrow = append(newrow, i)
- }
- integral = append(integral, newrow)
- }
- return integral
-}
-
-// ToAllIntegralImg creates a WithSq containing a regular and
-// squared Integral Image
-func ToAllIntegralImg(img *image.Gray) WithSq {
- var s WithSq
- s.Img = ToIntegralImg(img)
- s.Sq = ToSqIntegralImg(img)
- return s
-}
-
-
-// GetWindow gets the values of the corners of a square part of an
-// Integral Image, plus the dimensions of the part, which can
-// be used to quickly calculate the mean of the area
-func (i I) GetWindow(x, y, size int) Window {
- step := size / 2
-
- minx, miny := 0, 0
- maxy := len(i)-1
- maxx := len(i[0])-1
-
- if y > (step+1) {
- miny = y - step - 1
- }
- if x > (step+1) {
- minx = x - step - 1
- }
-
- if maxy > (y + step) {
- maxy = y + step
- }
- if maxx > (x + step) {
- maxx = x + step
- }
-
- return Window { i[miny][minx], i[miny][maxx], i[maxy][minx], i[maxy][maxx], maxx-minx, maxy-miny}
-}
-
-// GetVerticalWindow gets the values of the corners of a vertical
-// slice of an Integral Image, starting at x
-func (i I) GetVerticalWindow(x, width int) Window {
- maxy := len(i) - 1
- maxx := x + width
- if maxx > len(i[0])-1 {
- maxx = len(i[0]) - 1
- }
-
- return Window { i[0][x], i[0][maxx], i[maxy][x], i[maxy][maxx], width, maxy }
-}
-
-// Sum returns the sum of all pixels in a Window
-func (w Window) Sum() uint64 {
- return w.bottomright + w.topleft - w.topright - w.bottomleft
-}
-
-// Size returns the total size of a Window
-func (w Window) Size() int {
- return w.width * w.height
-}
-
-// Mean returns the average value of pixels in a Window
-func (w Window) Mean() float64 {
- return float64(w.Sum()) / float64(w.Size())
-}
-
-// Proportion returns the proportion of pixels which are on
-func (w Window) Proportion() float64 {
- area := w.width * w.height
- // divide by 255 as each on pixel has the value of 255
- sum := float64(w.Sum()) / 255
- return float64(area) / sum - 1
-}
-
-// MeanWindow calculates the mean value of a section of an Integral
-// Image
-func (i I) MeanWindow(x, y, size int) float64 {
- return i.GetWindow(x, y, size).Mean()
-}
-
-// MeanStdDevWindow calculates the mean and standard deviation of
-// a section on an Integral Image
-func (i WithSq) MeanStdDevWindow(x, y, size int) (float64, float64) {
- imean := i.Img.GetWindow(x, y, size).Mean()
- smean := i.Sq.GetWindow(x, y, size).Mean()
-
- variance := smean - (imean * imean)
-
- return imean, math.Sqrt(variance)
-}
--
cgit v1.2.1-24-ge1ad