diff options
| author | Nick White <git@njw.name> | 2020-07-29 18:18:40 +0100 |
|---|---|---|
| committer | Nick White <git@njw.name> | 2020-07-29 18:18:40 +0100 |
| commit | b9e6c0d3ced0f1d56418b8538c79eede0152171b (patch) | |
| tree | f537a54dcd7fed87d64672a07a5806a59adf69c8 | |
| parent | 8f22584952c2a3939caf0a69083931fcf3829a54 (diff) | |
Correct integral image implementation by ensuring that any request for column or row 0 returns 0 for calculations
| -rw-r--r-- | integralimg.go | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/integralimg.go b/integralimg.go index 53aec13..922b1ce 100644 --- a/integralimg.go +++ b/integralimg.go @@ -142,24 +142,36 @@ func highest(a, b int) int { func (i Image) topLeft(r image.Rectangle) uint64 { x := highest(r.Min.X, 0) y := highest(r.Min.Y, 0) + if x == 0 || y == 0 { + return 0 + } return i[y][x] } func (i Image) topRight(r image.Rectangle) uint64 { - x := lowest(r.Max.X, i.Bounds().Dx() - 1) + x := lowest(r.Max.X - 1, i.Bounds().Dx() - 1) y := highest(r.Min.Y, 0) + if x == 0 || y == 0 { + return 0 + } return i[y][x] } func (i Image) bottomLeft(r image.Rectangle) uint64 { x := highest(r.Min.X, 0) - y := lowest(r.Max.Y, i.Bounds().Dy() - 1) + y := lowest(r.Max.Y - 1, i.Bounds().Dy() - 1) + if x == 0 || y == 0 { + return 0 + } return i[y][x] } func (i Image) bottomRight(r image.Rectangle) uint64 { - x := lowest(r.Max.X, i.Bounds().Dx() - 1) - y := lowest(r.Max.Y, i.Bounds().Dy() - 1) + x := lowest(r.Max.X - 1, i.Bounds().Dx() - 1) + y := lowest(r.Max.Y - 1, i.Bounds().Dy() - 1) + if x == 0 || y == 0 { + return 0 + } return i[y][x] } |