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diff --git a/source/blender/freestyle/intern/image/GaussianFilter.cpp b/source/blender/freestyle/intern/image/GaussianFilter.cpp
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+++ b/source/blender/freestyle/intern/image/GaussianFilter.cpp
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+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * This program 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.
+ *
+ * This program 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 this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2010 Blender Foundation.
+ * All rights reserved.
+ *
+ * The Original Code is: all of this file.
+ *
+ * Contributor(s): none yet.
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+/** \file blender/freestyle/intern/image/GaussianFilter.cpp
+ *  \ingroup freestyle
+ *  \brief Class to perform gaussian filtering operations on an image
+ *  \author Stephane Grabli
+ *  \date 20/05/2003
+ */
+
+#include <stdlib.h>
+
+#include "GaussianFilter.h"
+
+GaussianFilter::GaussianFilter(float iSigma)
+{
+	_sigma = iSigma;
+	_mask = 0;
+	computeMask();
+}
+
+GaussianFilter::GaussianFilter(const GaussianFilter& iBrother)
+{
+	_sigma = iBrother._sigma;
+	_maskSize = iBrother._maskSize;
+	_bound = iBrother._bound;
+	_storedMaskSize = iBrother._storedMaskSize;
+	_mask = new float[_maskSize * _maskSize];
+	memcpy(_mask, iBrother._mask, _maskSize * _maskSize * sizeof(float));
+}
+
+GaussianFilter& GaussianFilter::operator=(const GaussianFilter& iBrother)
+{
+	_sigma = iBrother._sigma;
+	_maskSize = iBrother._maskSize;
+	_bound = iBrother._bound;
+	_storedMaskSize = iBrother._storedMaskSize;
+	_mask = new float[_storedMaskSize * _storedMaskSize];
+	memcpy(_mask, iBrother._mask, _storedMaskSize * _storedMaskSize * sizeof(float));
+	return *this;
+}
+
+
+GaussianFilter::~GaussianFilter()
+{
+	if (0 != _mask) {
+		delete[] _mask;
+	}
+}
+
+int GaussianFilter::computeMaskSize(float sigma)
+{
+	int maskSize = (int)floor(4 * sigma) + 1;
+	if (0 == (maskSize % 2))
+		++maskSize;
+
+	return maskSize;
+}
+
+void GaussianFilter::setSigma(float sigma)
+{
+	_sigma = sigma;
+	computeMask();
+}
+
+void GaussianFilter::computeMask()
+{
+	if (0 != _mask) {
+		delete[] _mask;
+	}
+
+	_maskSize = computeMaskSize(_sigma);
+	_storedMaskSize = (_maskSize + 1) >> 1;
+	_bound = _storedMaskSize - 1;
+
+	float norm = _sigma * _sigma * 2.0f * M_PI;
+	float invNorm = 1.0f / norm;
+	_mask = new float[_storedMaskSize * _storedMaskSize * sizeof(float)];
+	for (int i = 0; i < _storedMaskSize; ++i) {
+		for (int j = 0; j < _storedMaskSize; ++j) {
+#if 0
+			_mask[i * _storedMaskSize + j] = exp(-(i * i + j * j) / (2.0 * _sigma * _sigma));
+#else
+			_mask[i * _storedMaskSize + j] = invNorm * exp(-(i * i + j * j) / (2.0 * _sigma * _sigma));
+#endif
+		}
+	}
+}