diff --git a/src/mynteye/api/camera_models/util/matrix.h b/src/mynteye/api/camera_models/util/matrix.h
index 925ebf9..2943720 100644
--- a/src/mynteye/api/camera_models/util/matrix.h
+++ b/src/mynteye/api/camera_models/util/matrix.h
@@ -27,46 +27,46 @@ namespace ctain {
 template<typename _Scalar>
 class Matrix {
  public:
-  Matrix(int Rows, int Cols) :
-    _Rows(Rows), _Cols(Cols), _isSub(0), input_id(0) {
+  Matrix(int _rows, int _cols) :
+    _Rows(_rows), _Cols(_cols), _isSub(0), input_id(0) {
   _startRow = 0;
   _startCol = 0;
-  _Rows_raw = Rows;
-  _Cols_raw = Cols;
+  _Rows_raw = _rows;
+  _Cols_raw = _cols;
   data = new _Scalar[_Rows * _Cols];
   memset(data, 0, _Rows * _Cols * sizeof(_Scalar));
   }
-  Matrix() :
+  Matrix(void) :
     _Rows(0), _Cols(0), _isSub(0), input_id(0) {
   _startRow = 0;
   _startCol = 0;
   _Rows_raw = 0;
   _Cols_raw = 0;
   }
-  Matrix(_Scalar _data[], int Rows, int Cols) :
-      _Rows(Rows), _Cols(Cols), _isSub(0), input_id(0) {
+  Matrix(_Scalar _data[], int _rows, int _cols) :
+      _Rows(_rows), _Cols(_cols), _isSub(0), input_id(0) {
     _startRow = 0;
     _startCol = 0;
-    _Rows_raw = Rows;
-    _Cols_raw = Cols;
-    data = new _Scalar[Rows * _Cols];
+    _Rows_raw = _rows;
+    _Cols_raw = _cols;
+    data = new _Scalar[_rows * _Cols];
     memcpy(data, _data, _Rows * _Cols * sizeof(_Scalar));
   }
 
-  Matrix(_Scalar **_data, int Rows, int Cols) :
-      _Rows(Rows), _Cols(Cols), _isSub(0), input_id(0) {
+  Matrix(_Scalar **_data, int _rows, int _cols) :
+      _Rows(_rows), _Cols(_cols), _isSub(0), input_id(0) {
     _startRow = 0;
     _startCol = 0;
-    _Rows_raw = Rows;
-    _Cols_raw = Cols;
-    data = new _Scalar[Rows * _Cols];
+    _Rows_raw = _rows;
+    _Cols_raw = _cols;
+    data = new _Scalar[_rows * _Cols];
     for (int i = 0; i < _Rows; ++i) {
     memcpy(data + i * _Cols, *(_data + i), _Cols * sizeof(_Scalar));
     }
   }
 
   template<typename T>
-  Matrix<T> cast() {
+  Matrix<T> cast(void) const{
     Matrix<T> res(_Rows, _Cols);
     for (int i = 0; i < _Rows; i++) {
       for (int j = 0; j < _Cols; j++) {
@@ -76,7 +76,7 @@ class Matrix {
     return res;
   }
 
-  void setIdentity() {
+  void setIdentity(void) {
     for (int i = 0; i < _Rows; i++) {
       for (int j = 0; j < _Cols; j++) {
         if (i == j) {
@@ -87,19 +87,19 @@ class Matrix {
       }
     }
   }
-  void setZero() {
+  void setZero(void) {
     for (int i = 0; i < _Rows; i++) {
       for (int j = 0; j < _Cols; j++) {
         Data(i, j) = 0;
       }
     }
   }
-  inline int cols() const { return _Cols; }
+  inline int cols(void) const { return _Cols; }
 
-  inline int rows() const { return _Rows; }
+  inline int rows(void) const { return _Rows; }
 
-  inline int size() const { return cols() * rows(); }
-  inline _Scalar * addr() {
+  inline int size(void) const { return cols() * rows(); }
+  inline _Scalar * addr(void) {
     return data;
   }
 
@@ -196,49 +196,49 @@ class Matrix {
   Matrix<_Scalar> row(int Row) {
     return block(Row, 0, 1, _Cols);
   }
-  Matrix<_Scalar> block(int sRow, int sCol, int Rows, int Cols) {
+  Matrix<_Scalar> block(int sRow, int sCol, int _rows, int _cols) {
     Matrix<_Scalar> sub;
     sub = *this;
-    sub.setSub(sRow, sCol, Rows, Cols, data);
+    sub.setSub(sRow, sCol, _rows, _cols, data);
     return sub;
   }
 
-  template<int Rows, int Cols>
-  Matrix<_Scalar> topLeftCorner() {
+  template<int _rows, int _cols>
+  Matrix<_Scalar> topLeftCorner(void) {
     Matrix<_Scalar> sub;
     sub = *this;
-    sub.setSub(0, 0, Rows, Cols, data);
+    sub.setSub(0, 0, _rows, _cols, data);
     return sub;
   }
 
-  template<int Rows, int Cols>
-  Matrix<_Scalar> topRightCorner() {
+  template<int _rows, int _cols>
+  Matrix<_Scalar> topRightCorner(void) {
     Matrix<_Scalar> sub;
     sub = *this;
-    sub.setSub(0, _Cols-Cols, Rows, Cols, data);
+    sub.setSub(0, _Cols-_cols, _rows, _cols, data);
     return sub;
   }
 
-  void setSub(int sRow, int sCol, int Rows, int Cols, _Scalar *Data) {
+  void setSub(int sRow, int sCol, int _rows, int _cols, _Scalar *Data) {
     _isSub = true;
     _Rows_raw = _Rows;
     _Cols_raw = _Cols;
-    _Rows = Rows;
-    _Cols = Cols;
+    _Rows = _rows;
+    _Cols = _cols;
     _startRow = sRow;
     _startCol = sCol;
     data = Data;
   }
 
-  void normalize();
-  double norm() const;
+  void normalize(void);
+  double norm(void) const;
 
   virtual ~Matrix() {
     if  (!data)
       delete[] data;
   }
 
-  inline _Scalar *Data() {
+  inline _Scalar *Data(void) {
     return data;
   }
 
@@ -349,7 +349,7 @@ Matrix<_Scalar> Matrix<_Scalar>::operator -(const Matrix<_Scalar> &m) const {
 }
 
 template<typename _Scalar>
-Matrix<_Scalar> Matrix<_Scalar>::transpose() const {
+Matrix<_Scalar> Matrix<_Scalar>::transpose(void) const {
   Matrix<_Scalar> res(_Cols, _Rows);
   for (int i = 0; i < _Rows; i++) {
     for (int j = 0; j < _Cols; j++) {
@@ -392,7 +392,7 @@ Matrix<_Scalar> Matrix<_Scalar>::operator /(double m) const {
 
 
 template<typename _Scalar>
-void Matrix<_Scalar>::normalize() {
+void Matrix<_Scalar>::normalize(void) {
   double sum = 0;
   for (int i = 0; i < _Rows; i++) {
     for (int j = 0; j < _Cols; j++) {
@@ -408,7 +408,7 @@ void Matrix<_Scalar>::normalize() {
 }
 
 template<typename _Scalar>
-double Matrix<_Scalar>::norm() const {
+double Matrix<_Scalar>::norm(void) const {
   double sum = 0;
   for (int i = 0; i < _Rows; i++) {
     for (int j = 0; j < _Cols; j++) {
diff --git a/src/mynteye/api/camera_models/util/matrix_solver.h b/src/mynteye/api/camera_models/util/matrix_solver.h
index 2d100e5..b0d8a8c 100644
--- a/src/mynteye/api/camera_models/util/matrix_solver.h
+++ b/src/mynteye/api/camera_models/util/matrix_solver.h
@@ -20,9 +20,9 @@
 
 MYNTEYE_BEGIN_NAMESPACE
 
-static bool Matrix_EigenValue(double *K1, int n,
-    int LoopNumber, double Error1, double *Ret);
-static void Matrix_Hessenberg(double *A1, int n, double *ret);
+static bool Matrix_EigenValue(double *k1, int n,
+    int loop_number, double error1, double *ret);
+static void Matrix_Hessenberg(double *a1, int n, double *ret);
 
 namespace ctain {
 class EigenSolver {
@@ -40,7 +40,7 @@ class EigenSolver {
     delete []A;
     delete []B;
 }
-  Matrix<double> eigenvalues() {
+  Matrix<double> eigenvalues(void) {
     return t;
   }
 
@@ -50,7 +50,7 @@ class EigenSolver {
 
 }  // namespace ctain
 
-static void Matrix_Hessenberg(double *A1, int n, double *ret) {
+static void Matrix_Hessenberg(double *a1, int n, double *ret) {
   int MaxNumber;
   double temp, *A;
   A = new double[n*n];
@@ -58,7 +58,7 @@ static void Matrix_Hessenberg(double *A1, int n, double *ret) {
   for (int i = 0; i < n; i++) {
     int k = i * n;
     for (int j = 0; j < n; j++) {
-      A[k + j] = A1[k + j];
+      A[k + j] = a1[k + j];
     }
   }
   for (int k = 1; k < n-1; k++) {
@@ -106,21 +106,21 @@ static void Matrix_Hessenberg(double *A1, int n, double *ret) {
   delete []A;
 }
 
-static bool Matrix_EigenValue(double *K1, int n,
-    int LoopNumber, double Error1, double *Ret) {
+static bool Matrix_EigenValue(double *k1, int n,
+    int loop_number, double error1, double *ret) {
   int i, j, k, t, m, Loop1;
   double b, c, d, g, xy, p, q, r, x, s, e, f, z, y, temp, *A;
   A = new double[n * n];
   memset(A, 0, sizeof(double) * n * n);
-  Matrix_Hessenberg(K1, n, A);
+  Matrix_Hessenberg(k1, n, A);
   m = n;
-  Loop1 = LoopNumber;
+  Loop1 = loop_number;
   while (m != 0) {
     t = m - 1;
     while (t > 0) {
       temp = fabs(A[(t - 1) * n + t - 1]);
       temp += fabs(A[t * n + t]);
-      temp = temp * Error1;
+      temp = temp * error1;
       if (fabs(A[t * n + t - 1]) > temp) {
         t--;
       } else {
@@ -128,10 +128,10 @@ static bool Matrix_EigenValue(double *K1, int n,
       }
     }
     if (t == m-1) {
-      Ret[(m - 1) * 2] = A[(m - 1) * n + m - 1];
-      Ret[(m - 1) * 2 + 1] = 0;
+      ret[(m - 1) * 2] = A[(m - 1) * n + m - 1];
+      ret[(m - 1) * 2 + 1] = 0;
       m -= 1;
-      Loop1 = LoopNumber;
+      Loop1 = loop_number;
     } else if (t == m - 2) {
       b = -A[(m - 1) * n + m - 1] - A[(m - 2) * n + m - 2];
       c = A[(m - 1) * n + m - 1] * A[(m - 2) * n + m - 2]
@@ -143,18 +143,18 @@ static bool Matrix_EigenValue(double *K1, int n,
         if (b < 0) {
           xy = -1;
         }
-        Ret[(m - 1) * 2] = -(b + xy * y) / 2;
-        Ret[(m - 1) * 2 + 1] = 0;
-        Ret[(m - 2) * 2] = c / Ret[(m - 1) * 2];
-        Ret[(m - 2) * 2 + 1] = 0;
+        ret[(m - 1) * 2] = -(b + xy * y) / 2;
+        ret[(m - 1) * 2 + 1] = 0;
+        ret[(m - 2) * 2] = c / ret[(m - 1) * 2];
+        ret[(m - 2) * 2 + 1] = 0;
       } else {
-        Ret[(m - 1) * 2] = -b / 2;
-        Ret[(m - 2) * 2] = -b / 2;
-        Ret[(m - 1) * 2 + 1] = y / 2;
-        Ret[(m - 2) * 2 + 1] = -y / 2;
+        ret[(m - 1) * 2] = -b / 2;
+        ret[(m - 2) * 2] = -b / 2;
+        ret[(m - 1) * 2 + 1] = y / 2;
+        ret[(m - 2) * 2 + 1] = -y / 2;
       }
       m -= 2;
-      Loop1 = LoopNumber;
+      Loop1 = loop_number;
     } else {
       if (Loop1 < 1) {
         delete []A;
diff --git a/src/mynteye/api/camera_models/util/matrix_square.h b/src/mynteye/api/camera_models/util/matrix_square.h
index 05b4902..0fd95cb 100644
--- a/src/mynteye/api/camera_models/util/matrix_square.h
+++ b/src/mynteye/api/camera_models/util/matrix_square.h
@@ -24,14 +24,22 @@ namespace ctain {
 template<typename _Scalar>
 class SMatrix: public Matrix_{
  public:
-  explicit SMatrix(int D) : Matrix_(D, D) {}
+  explicit SMatrix(int dim) : Matrix_(dim, dim) {}
   SMatrix() : Matrix_(0, 0) {}
-  SMatrix(_Scalar _data[], int D) : Matrix_(_data, D, D) {}
-  SMatrix(_Scalar **_data, int D) : Matrix_(_data, D, D) {}
+  SMatrix(_Scalar _data[], int dim) : Matrix_(_data, dim, dim) {}
+  SMatrix(_Scalar **_data, int dim) : Matrix_(_data, dim, dim) {}
   explicit SMatrix(Matrix_ m) : Matrix_(m) {}
-  _Scalar determinant();
+  _Scalar determinant(void) const;
   _Scalar M(int m, int n);
-  SMatrix<_Scalar> inverse() {
+  SMatrix<_Scalar> inverse(void);
+  void operator =(Matrix<_Scalar> m) {
+    SMatrix t(m);
+    *this = t;
+  }
+};
+
+template<typename _Scalar>
+SMatrix<_Scalar> inverse(void) const{
     SMatrix<_Scalar> res(Matrix_::_Rows);
     _Scalar d = determinant();
     for (int i = 0; i < Matrix_::_Rows; i++) {
@@ -40,15 +48,10 @@ class SMatrix: public Matrix_{
         }
     }
     return res;
-  }
-  void operator =(Matrix<_Scalar> m) {
-    SMatrix t(m);
-    *this = t;
-  }
-};
+}
 
 template<typename _Scalar>
-_Scalar SMatrix<_Scalar>::determinant() {
+_Scalar SMatrix<_Scalar>::determinant(void) const{
   int r, c, m;
   int lop = 0;
   int n = Matrix_::_Rows;
diff --git a/src/mynteye/api/camera_models/util/quaternion.h b/src/mynteye/api/camera_models/util/quaternion.h
index 57c2d49..c1e73fa 100644
--- a/src/mynteye/api/camera_models/util/quaternion.h
+++ b/src/mynteye/api/camera_models/util/quaternion.h
@@ -25,7 +25,7 @@ namespace ctain {
 template<typename T>
 class Quaternion {
  public:
-  Quaternion() {}
+  Quaternion(void) {}
   explicit Quaternion(SMatrix<double> m) {
     _w = sqrt(m(0) + m(4) + m(8) + 1) / 2;
     _x = (m(5) - m(7)) / (4 * _w);
@@ -33,7 +33,7 @@ class Quaternion {
     _z = (m(1) - m(3)) / (4 * _w);
   }
   Quaternion(T X, T Y, T Z, T W) : _x(X), _y(Y), _z(Z), _w(W) {}
-  void normalize() {
+  void normalize(void) {
     double len;
     len = sqrt(_x * _x + _y * _y + _z * _z + _w * _w);
     _x = _x  /  len;
@@ -45,7 +45,7 @@ class Quaternion {
   inline T y() {return _y;}
   inline T z() {return _z;}
   inline T w() {return _w;}
-  SMatrix<double> toRotationMatrix() const {
+  SMatrix<double> toRotationMatrix(void) const {
     SMatrix<double> r(3);
     double q0 = _w, q1 = _x, q2 = _y, q3 = _z;
     r(0) = 1  -  2 * q2 * q2 - 2 * q3 * q3;