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-rw-r--r--integralimg/integralimg.go22
-rw-r--r--preproc/wipesides.go55
2 files changed, 32 insertions, 45 deletions
diff --git a/integralimg/integralimg.go b/integralimg/integralimg.go
index 31f3e53..406ed61 100644
--- a/integralimg/integralimg.go
+++ b/integralimg/integralimg.go
@@ -89,7 +89,7 @@ func ToAllIntegralImg(img *image.Gray) WithSq {
}
-// GetWindow gets the values of the corners of a part of an
+// 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 {
@@ -116,6 +116,18 @@ func (i I) GetWindow(x, y, size int) Window {
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
@@ -131,6 +143,14 @@ 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 {
diff --git a/preproc/wipesides.go b/preproc/wipesides.go
index 4806e93..5291d00 100644
--- a/preproc/wipesides.go
+++ b/preproc/wipesides.go
@@ -1,7 +1,7 @@
package preproc
// TODO: add minimum size variable (default ~30%?)
-// TODO: have the integral image specific stuff done by interface functions
+// TODO: switch to an interface rather than integralimg.I
import (
"image"
@@ -10,48 +10,15 @@ import (
"rescribe.xyz/go.git/integralimg"
)
-type IntWindow struct { // TODO: put this in its own package
- topleft uint64
- topright uint64
- bottomleft uint64
- bottomright uint64
- width int
- height int
-}
-
-type IntImg [][]uint64 // TODO: put this in its own package
-
-func (i IntImg) WindowSlice(x int, size int) IntWindow {
- maxy := len(i) - 1
- maxx := x + size
- if maxx > len(i[0])-1 {
- maxx = len(i[0]) - 1
- }
-
- return IntWindow{i[0][x], i[0][maxx], i[maxy][x], i[maxy][maxx], size, maxy}
-}
-
-// Sum returns how many pixels are on
-func (i IntWindow) Sum() uint64 {
- // divide by 255 as each on pixel has the value of 255
- return (i.bottomright + i.topleft - i.topright - i.bottomleft) / 255
-}
-
-// Proportion returns the proportion of pixels which are on
-func (i IntWindow) Proportion() float64 {
- area := i.width * i.height
- return float64(area) / float64(i.Sum()) - 1
-}
-
// returns the proportion of the given window that is black pixels
-func proportion(integral IntImg, x int, size int) float64 {
- w := integral.WindowSlice(x, size)
+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(integral [][]uint64, x int, w int) int {
+func findbestedge(img integralimg.I, x int, w int) int {
var bestx int
var best float64
@@ -61,7 +28,7 @@ func findbestedge(integral [][]uint64, x int, w int) int {
right := x + w
for ; x < right; x++ {
- prop := proportion(integral, x, 1)
+ prop := proportion(img, x, 1)
if prop > best {
best = prop
bestx = x
@@ -74,20 +41,20 @@ func findbestedge(integral [][]uint64, x int, w int) int {
// 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
+func findedges(img integralimg.I, wsize int, thresh float64) (int, int) {
+ maxx := len(img[0]) - 1
var lowedge, highedge int = 0, maxx
for x := maxx / 2; x < maxx-wsize; x++ {
- if proportion(integral, x, wsize) <= thresh {
- highedge = findbestedge(integral, x, wsize)
+ if proportion(img, x, wsize) <= thresh {
+ highedge = findbestedge(img, x, wsize)
break
}
}
for x := maxx / 2; x > 0; x-- {
- if proportion(integral, x, wsize) <= thresh {
- lowedge = findbestedge(integral, x, wsize)
+ if proportion(img, x, wsize) <= thresh {
+ lowedge = findbestedge(img, x, wsize)
break
}
}