diff options
| -rw-r--r-- | integralimg/integralimg.go | 22 | ||||
| -rw-r--r-- | preproc/wipesides.go | 55 |
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 } } |