From 5748cea80dfadb09c0de46f786d56b6851ef11ec Mon Sep 17 00:00:00 2001
From: Olexa Bilaniuk <obilaniu@gmail.com>
Date: Thu, 26 Feb 2015 21:47:29 -0500
Subject: [PATCH] Removed unnecessary precision in damped Cholesky
 decomposition.

Cholesky decomposition is stable; It is not necessary to carry it out
internally at double precision if the result will be truncated to single
precision when stored.
---
 modules/calib3d/src/rhorefc.cpp | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/modules/calib3d/src/rhorefc.cpp b/modules/calib3d/src/rhorefc.cpp
index 86d2f09770..8372d251ae 100644
--- a/modules/calib3d/src/rhorefc.cpp
+++ b/modules/calib3d/src/rhorefc.cpp
@@ -2129,28 +2129,28 @@ static inline int    sacChol8x8Damped(const float (*A)[8],
     const register int N = 8;
     int i, j, k;
     float  lambdap1 = lambda + 1.0f;
-    double x;
+    float  x;
 
     for(i=0;i<N;i++){/* Row */
         /* Pre-diagonal elements */
         for(j=0;j<i;j++){
-            x = A[i][j];                       /* Aij */
+            x = A[i][j];               /* Aij */
             for(k=0;k<j;k++){
-                x -= (double)L[i][k] * L[j][k];/* - Sum_{k=0..j-1} Lik*Ljk */
+                x -= L[i][k] * L[j][k];/* - Sum_{k=0..j-1} Lik*Ljk */
             }
-            L[i][j] = (float)(x / L[j][j]);    /* Lij = ... / Ljj */
+            L[i][j] = x / L[j][j];     /* Lij = ... / Ljj */
         }
 
         /* Diagonal element */
         {j = i;
-            x = A[j][j] * lambdap1;            /* Ajj */
+            x = A[j][j] * lambdap1;    /* Ajj */
             for(k=0;k<j;k++){
-                x -= (double)L[j][k] * L[j][k];/* - Sum_{k=0..j-1} Ljk^2 */
+                x -= L[j][k] * L[j][k];/* - Sum_{k=0..j-1} Ljk^2 */
             }
             if(x<0){
                 return 0;
             }
-            L[j][j] = (float)sqrt(x);          /* Ljj = sqrt( ... ) */
+            L[j][j] = sqrtf(x);        /* Ljj = sqrt( ... ) */
         }
     }