1 stable release
1.0.0 | Sep 19, 2022 |
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#1289 in Math
266 downloads per month
Used in mss_saliency
12KB
198 lines
Summed Area Table AKA Integral Image
It precomputes sums of all rows and columns in a 2d array for fast O(1)
querying of sums of areas within it.
It does this:
let mut sum = 0;
for row in y1..y2 {
for col in x1..x2 {
sum += input[col + row * width];
}
}
but faster:
// precompute
let s = SummedArea::new(input, width);
// now it's fast:
let sum = s.sum_range(x1..x2, y1..y2);
Dependencies
~62KB