Summed Area Table barryclark#6

kilinco · Sep 11, 2021 · 5acf272 · 5acf272
1 parent af59c54
commit 5acf272
Showing 1 changed file with 6 additions and 6 deletions.
diff --git a/_posts/2021-09-13-summed-area-table.md b/_posts/2021-09-13-summed-area-table.md
@@ -74,23 +74,23 @@ class SummedAreaTable {
     }
 
     int get_submatrix_sum(int x_low, int y_low, int x_high, int y_high) const;
-    int get_submatrix_mean(int x_low, int y_low, int x_high, int y_high) const;
-  private:
     int get_num_elements(int x_low, int y_low, int x_high, int y_high) const;
+    double get_submatrix_mean(int x_low, int y_low, int x_high, int y_high) const;
+  private:
     std::vector<std::vector<int>> dp;
 }
 
 int SummedAreaTable::get_submatrix_sum(int x_low, int y_low, int x_high, int y_high) const {
     return dp[x_high+1][y_high+1] - dp[x_high+1][y_low] - dp[x_low][y_high+1] + dp[x_low][y_low];
 }
 
-int SummedAreaTable::get_submatrix_mean(int x_low, int y_low, int x_high, int y_high) const {
-    return (double) get_submatrix_sum(x_low, y_low, x_high, y_high) / get_num_elements(x_low, y_low, x_high, y_high);
-}
-
 int SummedAreaTable::get_num_elements(int x_low, int y_low, int x_high, int y_high) const {
     return (x_high - x_low + 1) * (y_high - y_low + 1);
 }
+
+double SummedAreaTable::get_submatrix_mean(int x_low, int y_low, int x_high, int y_high) const {
+    return std::static_cast<double>(get_submatrix_sum(x_low, y_low, x_high, y_high)) / get_num_elements(x_low, y_low, x_high, y_high);
+}
 {% endhighlight %}
 
 Lastly, you can find the much better illustrated solution [here](https://nayan.co/blog/AI/Integral-Image/).