/*
* Copyright (C) 2007-2008 Anael Orlinski
*
* This file is part of Panomatic.
*
* Panomatic is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
* 
* Panomatic is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
* GNU General Public License for more details.
* 
* You should have received a copy of the GNU General Public License
* along with Panomatic; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#include <iostream>
#include <vector>

#include "Image.h"

using namespace lfeat;
using namespace std;

Image::Image(double *iPixels, unsigned int iWidth, unsigned int iHeight, bool integral)
{
	init(iPixels, iWidth, iHeight, integral);
}

void Image::init(double *iPixels, unsigned int iWidth, unsigned int iHeight, bool integral)
{
	typedef double * double_ptr;
	// store values

	if (! integral) {
		_width = iWidth;
		_height = iHeight;
		_pixels = new double_ptr[iHeight];
		_pixels[0] = iPixels;
		for (unsigned int i=1; i <  iHeight; i++) {
			_pixels[i] = _pixels[i-1] + iWidth;
		}
	
		// allocate the integral image data
		_ii = AllocateImage(_width + 1, _height + 1);
		_own_ii = true;

		// create the integral image
		buildIntegralImage();
	} else {
		_width = iWidth -1;
		_height = iHeight -1;
		_pixels = 0;
		// just set the integral image
		_ii = new double_ptr[iHeight];
		_ii[0] = iPixels;
		for (unsigned int i=1; i <  iHeight; i++) {
			_ii[i] = _ii[i-1] + iWidth;
		}
		_own_ii = false;
	}
}

void Image::clean()
{
	if (_ii && _own_ii) {
		DeallocateImage(_ii, _height + 1);
	} else if (_ii) {
		delete[] _ii;
	}
	_ii = 0;
	if (_pixels)
		delete[] _pixels;
	_pixels = 0;
}


Image::~Image()
{
	clean();
}

void Image::buildIntegralImage()
{
	// to make easier the later computation, shift the image by 1 pix (x and y)
	// so the image has a size of +1 for width and height compared to orig image.

	// fill first line with zero
	for(unsigned int i = 0; i <= _width; ++i)
		_ii[0][i] = 0;

	// fill first row with zero
	for(unsigned int i = 0; i <= _height; ++i)
		_ii[i][0] = 0;

	// compute all the others pixels
	for(unsigned int i = 1; i <= _height; ++i)
		for(unsigned int j = 1; j <= _width; ++j)
			_ii[i][j] = _pixels[i-1][j-1] + _ii[i-1][j] + _ii[i][j-1] - _ii[i-1][j-1];

}

// allocate and deallocate pixels
double** Image::AllocateImage(unsigned int iWidth, unsigned int iHeight)
{
	// create the lines holder
	double ** aImagePtr = new double* [iHeight];

	// create the lines
	for(unsigned int i = 0; i < iHeight; ++i)
		aImagePtr[i] = new double[iWidth];

	return aImagePtr;
}

void Image::DeallocateImage(double **iImagePtr, unsigned int iHeight)
{
	// delete the lines
	for(unsigned int i = 0; i < iHeight; ++i)
		delete[] iImagePtr[i];

	// delete the lines holder
	delete[] iImagePtr;

}