rgbmin2gray.cpp

barcode readers [ from Image]

//
// RgbMin2Gray
//   Converts an input color image into an output gray image. Does not change the
//   data type.
//
// Copyright (C) 2003, 2006 by Jon A. Webb (Contact via GMail; username is jonawebb)
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
// 
// This library 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
// Lesser General Public License for more details.
// 
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
//

#include "RgbMin2Gray.h"

#include "GrayImageIter.h"
#include "Image.h"
#include "ImageSize.h"
#include "Replicate.h"
#include "RGBImageIter.h"

#include <e32std.h>
#include <fbs.h>

using namespace Core;

namespace Algorithm
{

	EXPORT_C CRgbMin2Gray* CRgbMin2Gray::NewL()
	{	
		return new (ELeave) CRgbMin2Gray();	
	}

	CRgbMin2Gray::~CRgbMin2Gray()
	{
	}

	CRgbMin2Gray::CRgbMin2Gray() :
		ibEmpty(true)
	{
	}

	CImage CRgbMin2Gray::FrontL() 
	{
		if (ibEmpty) {
			User::Leave(KErrGeneral);
			return CImage();
		}
		ibEmpty = true;
		return iImage;
	}

	void CRgbMin2Gray::PushL(CImage image)
	{
		IReplicate rRepl(image);
		rRepl.CastL(iImage, EGray256);

		image.LockLC();
		IGrayImageIter rGray(iImage);
		IRgbImageIter rRgb(image);

		for (rGray.Reset(),rRgb.Reset(); !rRgb.End(); rRgb.NextRow(), rGray.NextRow()) {
			for (; !rRgb.REnd(); rRgb++, rGray++) {
                unsigned char nMin = Min(rRgb[R], rRgb[G]);
				nMin = Min(nMin, rRgb[B]);
				rGray() = nMin;
			}
		}
		CleanupStack::PopAndDestroy(); // unlock bitmaps
		ibEmpty = false;
	}

	bool CRgbMin2Gray::Empty() const
	{
		return ibEmpty;
	}

};