↓ ↑	↓ ↑	↓ ↑
naive over	26 Aug 10	74.3k
NODR	26 Aug 10	68.1k
shad high	26 Aug 10	64.4k
by hand	26 Aug 10	64.3k
median mask	26 Aug 10	53.9k
gaussian mask	26 Aug 10	48.6k
linear	26 Aug 10	38.2k