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LaplacianOfGaussianImage.C

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00001 /*---------------------------------------------------------------------+
00002  | Library QgarLib, graphics analysis and recognition                  |
00003  | Copyright (C) 2002  Qgar Project, LORIA                             |
00004  |                                                                     |
00005  | This library is free software; you can redistribute it and/or       |
00006  | modify it under the terms of the GNU Lesser General Public          |
00007  | License version 2.1, as published by the Free Software Foundation.  |
00008  |                                                                     |
00009  | This library is distributed in the hope that it will be useful,     |
00010  | but WITHOUT ANY WARRANTY; without even the implied warranty of      |
00011  | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.                |
00012  | See the GNU Lesser General Public License for more details.         |
00013  |                                                                     |
00014  | The GNU Lesser General Public License is included in the file       |
00015  | LICENSE.LGPL, in the root directory of the Qgar packaging. See      |
00016  | http://www.gnu.org/licenses/lgpl.html for the terms of the licence. |
00017  | To receive a paper copy, write to the Free Software Foundation,     |
00018  | Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.       |
00019  |                                                                     |
00020  | Contact Project Qgar for any information:                           |
00021  |   LORIA - équipe Qgar                                               |
00022  |   B.P. 239, 54506 Vandoeuvre-lès-Nancy Cedex, France                |
00023  |   email: qgar-contact@loria.fr                                      |
00024  |   http://www.qgar.org/                                              |
00025  *---------------------------------------------------------------------*/
00026 
00027 
00028 /**
00029  * @file   LaplacianOfGaussianImage.C
00030  * @brief  Implementation of class qgar::LaplacianOfGaussianImage.
00031  *
00032  * See file LaplacianOfGaussianImage.H for the interface.
00033  *
00034  * @author <a href="mailto:qgar-develop@loria.fr?subject=Qgar fwd Karl Tombre">Karl Tombre</a>
00035  * @date   July 3, 2001  15:01
00036  * @since  Qgar 1.0
00037  */
00038 
00039 
00040 
00041 // QGAR
00042 #include <qgarlib/GenConvolImage.H>
00043 #include <qgarlib/GenImage.H>
00044 #include <qgarlib/LaplacianOfGaussianImage.H>
00045 #include <qgarlib/Mask1dGaussD2.H>
00046 #include <qgarlib/Mask1dGauss.H>
00047 
00048 
00049 
00050 namespace qgar
00051 {
00052 
00053 
00054 // -------------------------------------------------------------------
00055 // C O N S T R U C T O R S
00056 // -------------------------------------------------------------------
00057 
00058 
00059 // CONSTRUCT FROM GIVEN GREY-LEVEL IMAGE
00060 
00061 LaplacianOfGaussianImage::LaplacianOfGaussianImage(const GreyLevelImage& img,
00062                                                    double sigma) 
00063 
00064     : FloatImage(PRIVATEbuildLOGImage(img, sigma))
00065 
00066 {
00067   // VOID
00068 }
00069 
00070 
00071 // CONSTRUCT FROM GIVEN FLOAT IMAGE
00072 
00073 
00074 LaplacianOfGaussianImage::LaplacianOfGaussianImage(const FloatImage& img,
00075                                                    double sigma) 
00076 
00077     : FloatImage(PRIVATEbuildLOGImage(GreyLevelImage(img), sigma))
00078 
00079 {
00080   // VOID
00081 }
00082 
00083 
00084 
00085 // -------------------------------------------------------------------
00086 // A U X I L I A R I E S
00087 // -------------------------------------------------------------------
00088 
00089 
00090 FloatImage
00091 LaplacianOfGaussianImage::PRIVATEbuildLOGImage(const GreyLevelImage& img, 
00092                                                double aSigma)
00093 {
00094   // By construction, the float image contains a copy of the original
00095   // image to be derived
00096 
00097   // Create Gaussian masks
00098   Mask1dGauss   sMask(aSigma);  // smoothing mask
00099   Mask1dGaussD2 dMask(aSigma);  // second derivative mask
00100 
00101   FConvolImage * dx = new FConvolImage(img, dMask, QGE_AXIS_X);
00102   FConvolImage  imgx(*dx, sMask, QGE_AXIS_Y);
00103 
00104   delete dx;
00105 
00106   dx = new FConvolImage(img, sMask, QGE_AXIS_X);
00107   FConvolImage imgy(*dx, dMask, QGE_AXIS_Y);
00108 
00109   delete dx;
00110 
00111   // Add the two images
00112   imgx += imgy;
00113  
00114   return imgx;
00115 }
00116 
00117 // ----------------------------------------------------------------------
00118 
00119 } // namespace qgar
00120