Merge pull request #11904 from terfendail/matx_solve_fix

Fixed Matx::solve function for non-square matrixes (#11904)

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

@@ -61,7 +61,16 @@ namespace cv
 namespace internal
 {
 
-template<typename _Tp, int m> struct Matx_FastInvOp
+template<typename _Tp, int m, int n> struct Matx_FastInvOp
+{
+    bool operator()(const Matx<_Tp, m, n>&, Matx<_Tp, n, m>&, int) const
+    {
+        CV_Assert(false);
+        return false;
+    }
+};
+
+template<typename _Tp, int m> struct Matx_FastInvOp<_Tp, m, m>
 {
     bool operator()(const Matx<_Tp, m, m>& a, Matx<_Tp, m, m>& b, int method) const
     {
@@ -78,7 +87,7 @@ template<typename _Tp, int m> struct Matx_FastInvOp
     }
 };
 
-template<typename _Tp> struct Matx_FastInvOp<_Tp, 2>
+template<typename _Tp> struct Matx_FastInvOp<_Tp, 2, 2>
 {
     bool operator()(const Matx<_Tp, 2, 2>& a, Matx<_Tp, 2, 2>& b, int) const
     {
@@ -94,7 +103,7 @@ template<typename _Tp> struct Matx_FastInvOp<_Tp, 2>
     }
 };
 
-template<typename _Tp> struct Matx_FastInvOp<_Tp, 3>
+template<typename _Tp> struct Matx_FastInvOp<_Tp, 3, 3>
 {
     bool operator()(const Matx<_Tp, 3, 3>& a, Matx<_Tp, 3, 3>& b, int) const
     {
@@ -118,7 +127,17 @@ template<typename _Tp> struct Matx_FastInvOp<_Tp, 3>
 };
 
 
-template<typename _Tp, int m, int n> struct Matx_FastSolveOp
+template<typename _Tp, int m, int l, int n> struct Matx_FastSolveOp
+{
+    bool operator()(const Matx<_Tp, m, l>&, const Matx<_Tp, m, n>&,
+                    Matx<_Tp, l, n>&, int) const
+    {
+        CV_Assert(false);
+        return false;
+    }
+};
+
+template<typename _Tp, int m, int n> struct Matx_FastSolveOp<_Tp, m, m, n>
 {
     bool operator()(const Matx<_Tp, m, m>& a, const Matx<_Tp, m, n>& b,
                     Matx<_Tp, m, n>& x, int method) const
@@ -132,7 +151,7 @@ template<typename _Tp, int m, int n> struct Matx_FastSolveOp
     }
 };
 
-template<typename _Tp> struct Matx_FastSolveOp<_Tp, 2, 1>
+template<typename _Tp> struct Matx_FastSolveOp<_Tp, 2, 2, 1>
 {
     bool operator()(const Matx<_Tp, 2, 2>& a, const Matx<_Tp, 2, 1>& b,
                     Matx<_Tp, 2, 1>& x, int) const
@@ -147,7 +166,7 @@ template<typename _Tp> struct Matx_FastSolveOp<_Tp, 2, 1>
     }
 };
 
-template<typename _Tp> struct Matx_FastSolveOp<_Tp, 3, 1>
+template<typename _Tp> struct Matx_FastSolveOp<_Tp, 3, 3, 1>
 {
     bool operator()(const Matx<_Tp, 3, 3>& a, const Matx<_Tp, 3, 1>& b,
                     Matx<_Tp, 3, 1>& x, int) const
@@ -195,7 +214,7 @@ Matx<_Tp, n, m> Matx<_Tp, m, n>::inv(int method, bool *p_is_ok /*= NULL*/) const
     Matx<_Tp, n, m> b;
     bool ok;
     if( m == n && (method == DECOMP_LU || method == DECOMP_CHOLESKY) )
-        ok = cv::internal::Matx_FastInvOp<_Tp, m>()(*reinterpret_cast<const Matx<_Tp, m, m>*>(this), reinterpret_cast<Matx<_Tp, m, m>&>(b), method);
+        ok = cv::internal::Matx_FastInvOp<_Tp, m, n>()(*this, b, method);
     else
     {
         Mat A(*this, false), B(b, false);
@@ -210,8 +229,8 @@ Matx<_Tp, n, l> Matx<_Tp, m, n>::solve(const Matx<_Tp, m, l>& rhs, int method) c
 {
     Matx<_Tp, n, l> x;
     bool ok;
-    if( method == DECOMP_LU || method == DECOMP_CHOLESKY )
-        ok = cv::internal::Matx_FastSolveOp<_Tp, m, l>()(*this, rhs, x, method);
+    if( m == n && (method == DECOMP_LU || method == DECOMP_CHOLESKY) )
+        ok = cv::internal::Matx_FastSolveOp<_Tp, m, n, l>()(*this, rhs, x, method);
     else
     {
         Mat A(*this, false), B(rhs, false), X(x, false);

modules/core/test/test_math.cpp

@@ -3129,6 +3129,21 @@ TEST(Core_QR_Solver, accuracy64f)
     ASSERT_FALSE(solve(A, B, solutionQR, DECOMP_QR));
 }
 
+TEST(Core_Solve, regression_11888)
+{
+    cv::Matx<float, 3, 2> A(
+        2, 1,
+        3, 1,
+        6, 1
+    );
+    cv::Vec<float, 3> b(4, 5, 7);
+    cv::Matx<float, 2, 1> xQR = A.solve(b, DECOMP_QR);
+    cv::Matx<float, 2, 1> xSVD = A.solve(b, DECOMP_SVD);
+    EXPECT_LE(cvtest::norm(xQR, xSVD, CV_RELATIVE_L2), FLT_EPSILON);
+    cv::Matx<float, 2, 3> iA = A.inv(DECOMP_SVD);
+    EXPECT_LE(cvtest::norm(A*iA, Matx<float, 3, 3>::eye(), CV_RELATIVE_L2), 0.6);
+}
+
 softdouble naiveExp(softdouble x)
 {
     int exponent = x.getExp();