Merge pull request #12916 from lqy123000:bugfix_templmatch

* avoid rounding errors * imgproc: replace condition in matchTemplate
6 years ago · cceeca3052
parent d9d8ad20a0
commit cceeca3052
1 changed files with 6 additions and 1 deletions
--- a/modules/imgproc/src/templmatch.cpp
+++ b/modules/imgproc/src/templmatch.cpp
@ -947,7 +947,12 @@ static void common_matchTemplate( Mat& img, Mat& templ, Mat& result, int method,

            if( isNormed )
            {
-                t = std::sqrt(MAX(wndSum2 - wndMean2,0))*templNorm;
+                double diff2 = MAX(wndSum2 - wndMean2, 0);
+                if (diff2 <= std::min(0.5, 10 * FLT_EPSILON * wndSum2))
+                    t = 0; // avoid rounding errors
+                else
+                    t = std::sqrt(diff2)*templNorm;
+
                if( fabs(num) < t )
                    num /= t;
                else if( fabs(num) < t*1.125 )