1 files changed, 2 insertions, 0 deletions
diff --git a/util.go b/util.go
index f0864e9..304b209 100644
--- a/util.go
+++ b/util.go
@@ -79,6 +79,8 @@ func surrounding(img *image.Gray, x int, y int, size int) []int {
 	return s
 }
 
+// BinToZeroInv converts a binary thresholded image to a zero inverse
+// binary thresholded image
 func BinToZeroInv(bin *image.Gray, orig *image.RGBA) (*image.RGBA, error) {
 	b := bin.Bounds()
 	if !b.Eq(orig.Bounds()) {