Add on optional parameter to the matx invert function to know if this operation…

Add on optional parameter to the matx invert function to know if this operation is successfull without having to analyse the matrix (it may fail in case of bad preconditioning or inappropriate decomposition method)

modules/core/include/opencv2/core/matx.hpp

@@ -154,7 +154,7 @@ public:
     Matx<_Tp, n, m> t() const;
 
     //! invert matrix the matrix
-    Matx<_Tp, n, m> inv(int method=DECOMP_LU) const;
+    Matx<_Tp, n, m> inv(int method=DECOMP_LU, bool *p_is_ok = NULL) const;
 
     //! solve linear system
     template<int l> Matx<_Tp, n, l> solve(const Matx<_Tp, m, l>& rhs, int flags=DECOMP_LU) const;

modules/core/include/opencv2/core/operations.hpp

@@ -186,7 +186,7 @@ Matx<_Tp,m,n> Matx<_Tp,m,n>::randn(_Tp a, _Tp b)
 }
 
 template<typename _Tp, int m, int n> inline
-Matx<_Tp, n, m> Matx<_Tp, m, n>::inv(int method) const
+Matx<_Tp, n, m> Matx<_Tp, m, n>::inv(int method, bool *p_is_ok /*= NULL*/) const
 {
     Matx<_Tp, n, m> b;
     bool ok;
@@ -197,6 +197,7 @@ Matx<_Tp, n, m> Matx<_Tp, m, n>::inv(int method) const
         Mat A(*this, false), B(b, false);
         ok = (invert(A, B, method) != 0);
     }
+    if( NULL != p_is_ok ) { *p_is_ok = ok; }
     return ok ? b : Matx<_Tp, n, m>::zeros();
 }