Computing the Hough Transform

Listing 4: Class definition for HoughAccumulator base class and LineHoughAccumulator class.

class HoughAccum
{
protected:
  int m_dx, m_dy;
  vector<int> m_accum;
  int m_rowLength;
  int m_numAccumulated;
  virtual bool DoAddPoint(int x, int y)=0;
public:
  HoughAccum();
  virtual ~HoughAccum();
  virtual void Init(int dx, int dy)=0;
  virtual void Clear();

  bool AddPoint(int x, int y);

  int GetCell(int row, int col) { return m_accum[row*m_rowLength + col]; }
  void SetCell(int row, int col, int value) { 
                                 m_accum[row*m_rowLength + col] = value; }
  void GetAccumSize(int *numRows, int *numCols) 
  { 
    *numRows = m_accum.size()/m_rowLength;
    *numCols  = m_rowLength;
  }
  int NumAccumulated() { return m_numAccumulated; }
};
class LineHoughAccum 
  : public HoughAccum
{
protected:
  vector<int> m_cosTable;
  vector<int> m_sinTable;
  virtual bool DoAddPoint(int x, int y);
public:
  LineHoughAccum(int numAngleCells);
  virtual ~LineHoughAccum();
  virtual void Init(int dx, int dy);
};