Image.hpp

/****************************************************************************
*
* Image.hpp
*
* Purpose:  C++ wrapper for OpenCV IplImage which supports simple and 
*						efficient access to the image data
*
* Author: Donovan Parks, September 2007
*
* Based on code from: 
*  http://www.cs.iit.edu/~agam/cs512/lect-notes/opencv-intro/opencv-intro.html
******************************************************************************/

#ifndef _IMAGE_H_
#define _IMAGE_H_

#include <cv.h>
#include <cxcore.h>


// --- Image Iterator ---------------------------------------------------------

template <class T>
class ImageIterator 
{
public: 
  ImageIterator(IplImage* image, int x=0, int y=0, int dx= 0, int dy=0) :
       i(x), j(y), i0(0) 
	{    
    data = reinterpret_cast<T*>(image->imageData);
    step = image->widthStep / sizeof(T);
 
    nl= image->height;
    if ((y+dy)>0 && (y+dy) < nl) 
			nl= y+dy;

    if (y<0) 
			j=0;

    data += step*j;
 
    nc = image->width;
    if ((x+dx) > 0 && (x+dx) < nc) 
			nc = x+dx;

    nc *= image->nChannels;
    if (x>0) 
			i0 = x*image->nChannels;
    i = i0;
 
    nch = image->nChannels;
	}

 
  /* has next ? */
  bool operator!() const { return j < nl; }
 
  /* next pixel */
  ImageIterator& operator++() 
	{
		i++;
    if (i >= nc) 
		{ 
			i=i0; 
			j++; 
			data += step; 
		}
    return *this;
	}

  ImageIterator& operator+=(int s) 
	{
		i+=s;
    if (i >= nc) 
		{ 
			i=i0; 
			j++; 
			data += step; 
		}
    return *this;
	}

  /* pixel access */
  T& operator*() { return data[i]; }

  const T operator*() const { return data[i]; }

  const T neighbor(int dx, int dy) const
  { 
		return *(data+dy*step+i+dx); 
	}

  T* operator&() const { return data+i; }
 
  /* current pixel coordinates */
  int column() const { return i/nch; }
  int line() const { return j; }

private:
  int i, i0,j;
  T* data;
  int step;
  int nl, nc;
  int nch;
};

// --- Constants --------------------------------------------------------------

const unsigned char NUM_CHANNELS = 3;


// --- Pixel Types ------------------------------------------------------------

class RgbPixel
{
public:
	RgbPixel() {;}
	RgbPixel(unsigned char _r, unsigned char _g, unsigned char _b)
	{
		ch[0] = _r; ch[1] = _g; ch[2] = _b;
	}

	RgbPixel& operator=(const RgbPixel& rhs)
	{
		ch[0] = rhs.ch[0]; ch[1] = rhs.ch[1]; ch[2] = rhs.ch[2];
		return *this;
	}

	inline unsigned char& operator()(const int _ch)
	{
		return ch[_ch];
	}

	inline unsigned char operator()(const int _ch) const
	{
		return ch[_ch];
	}

	unsigned char ch[3];
};

class RgbPixelFloat
{
public:
	RgbPixelFloat() {;}
	RgbPixelFloat(float _r, float _g, float _b)
	{
		ch[0] = _r; ch[1] = _g; ch[2] = _b;
	}

	RgbPixelFloat& operator=(const RgbPixelFloat& rhs)
	{
		ch[0] = rhs.ch[0]; ch[1] = rhs.ch[1]; ch[2] = rhs.ch[2];
		return *this;
	}

	inline float& operator()(const int _ch)
	{
		return ch[_ch];
	}

	inline float operator()(const int _ch) const
	{
		return ch[_ch];
	}

	float ch[3];
};


// --- Image Types ------------------------------------------------------------

class ImageBase
{
public:
 ImageBase(IplImage* img = NULL) { imgp = img; m_bReleaseMemory = true; }
  ~ImageBase();

	void ReleaseMemory(bool b) { m_bReleaseMemory = b; }

	IplImage* Ptr() { return imgp; }
	const IplImage* Ptr() const { return imgp; }

	void operator=(IplImage* img) 
	{ 
		imgp = img;
	}

	// copy-constructor
	ImageBase(const ImageBase& rhs)
	{	
		// it is very inefficent if this copy-constructor is called
		assert(false);
	}

	// assignment operator
	ImageBase& operator=(const ImageBase& rhs)
	{
		// it is very inefficent if operator= is called
		assert(false);

		return *this;
	}

	virtual void Clear() = 0;

protected:
	IplImage* imgp;
	bool m_bReleaseMemory;
};

class RgbImage : public ImageBase
{
public:
	RgbImage(IplImage* img = NULL) : ImageBase(img) { ; }

	virtual void Clear()
	{
		cvZero(imgp);
	}

	void operator=(IplImage* img) 
	{ 
		imgp = img;
	}

	// channel-level access using image(row, col, channel)
	inline unsigned char& operator()(const int r, const int c, const int ch)
	{
		return (unsigned char &)imgp->imageData[r*imgp->widthStep+c*imgp->nChannels+ch];
	}

	inline const unsigned char& operator()(const int r, const int c, const int ch) const
	{
		return (unsigned char &)imgp->imageData[r*imgp->widthStep+c*imgp->nChannels+ch];
	}

	// RGB pixel-level access using image(row, col)
	inline RgbPixel& operator()(const int r, const int c) 
	{
    return (RgbPixel &)imgp->imageData[r*imgp->widthStep+c*imgp->nChannels];
	}

	inline const RgbPixel& operator()(const int r, const int c) const
	{
    return (RgbPixel &)imgp->imageData[r*imgp->widthStep+c*imgp->nChannels];
	}
};

class RgbImageFloat : public ImageBase
{
public:
	RgbImageFloat(IplImage* img = NULL) : ImageBase(img) { ; }

	virtual void Clear()
	{
		cvZero(imgp);
	}

	void operator=(IplImage* img) 
	{ 
		imgp = img;
	}

	// channel-level access using image(row, col, channel)
	inline float& operator()(const int r, const int c, const int ch)
	{
		return (float &)imgp->imageData[r*imgp->widthStep+(c*imgp->nChannels+ch)*sizeof(float)];
	}

	inline float operator()(const int r, const int c, const int ch) const
	{
		return (float)imgp->imageData[r*imgp->widthStep+(c*imgp->nChannels+ch)*sizeof(float)];
	}

	// RGB pixel-level access using image(row, col)
	inline RgbPixelFloat& operator()(const int r, const int c) 
	{
    return (RgbPixelFloat &)imgp->imageData[r*imgp->widthStep+c*imgp->nChannels*sizeof(float)];
	}

	inline const RgbPixelFloat& operator()(const int r, const int c) const
	{
    return (RgbPixelFloat &)imgp->imageData[r*imgp->widthStep+c*imgp->nChannels*sizeof(float)];
	}
};

class BwImage : public ImageBase
{
public:
	BwImage(IplImage* img = NULL) : ImageBase(img) { ; }

	virtual void Clear()
	{
		cvZero(imgp);
	}

	void operator=(IplImage* img) 
	{ 
		imgp = img;
	}

	// pixel-level access using image(row, col)
	inline unsigned char& operator()(const int r, const int c)
	{
		return (unsigned char &)imgp->imageData[r*imgp->widthStep+c];
	}

	inline unsigned char operator()(const int r, const int c) const
	{
		return (unsigned char)imgp->imageData[r*imgp->widthStep+c];
	}
};

class BwImageFloat : public ImageBase
{
public:
	BwImageFloat(IplImage* img = NULL) : ImageBase(img) { ; }

	virtual void Clear()
	{
		cvZero(imgp);
	}

	void operator=(IplImage* img) 
	{ 
		imgp = img;
	}

	// pixel-level access using image(row, col)
	inline float& operator()(const int r, const int c)
	{
		return (float &)imgp->imageData[r*imgp->widthStep+c*sizeof(float)];
	}

	inline float operator()(const int r, const int c) const
	{
		return (float)imgp->imageData[r*imgp->widthStep+c*sizeof(float)];
	}
};



// --- Image Functions --------------------------------------------------------

void DensityFilter(BwImage& image, BwImage& filtered, int minDensity, unsigned char fgValue);

#endif