1 files changed, 96 insertions, 0 deletions
diff --git a/src/silx/math/fit/filters/src/snip2d.c b/src/silx/math/fit/filters/src/snip2d.c
new file mode 100644
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+++ b/src/silx/math/fit/filters/src/snip2d.c
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+#/*##########################################################################
+#
+# The PyMca X-Ray Fluorescence Toolkit
+#
+# Copyright (c) 2004-2014 European Synchrotron Radiation Facility
+#
+# This file is part of the PyMca X-ray Fluorescence Toolkit developed at
+# the ESRF by the Software group.
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+#
+#############################################################################*/
+/*
+   Implementation of the algorithm SNIP in 2D described in
+   Miroslav Morhac et al. Nucl. Instruments and Methods in Physics Research A401 (1997) 113-132.
+*/
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+#define MIN(x, y) (((x) < (y)) ? (x) : (y))
+#define MAX(x, y) (((x) > (y)) ? (x) : (y))
+
+void lls(double *data, int size);
+void lls_inv(double *data, int size);
+
+void snip2d(double *data, int nrows, int ncolumns, int width)
+{
+	int i, j;
+	int p;
+	int size;
+	double *w;
+	double P1, P2, P3, P4;
+	double S1, S2, S3, S4;
+	double dhelp;
+	int	iminuspxncolumns; /* (i-p) * ncolumns */
+	int	ixncolumns; /*  i * ncolumns */
+	int	ipluspxncolumns; /* (i+p) * ncolumns */
+
+	size = nrows * ncolumns;
+	w = (double *) malloc(size * sizeof(double));
+
+	for (p=width; p > 0; p--)
+	{
+		for (i=p; i<(nrows-p); i++)
+		{
+			iminuspxncolumns = (i-p) * ncolumns;
+			ixncolumns = i * ncolumns;
+			ipluspxncolumns = (i+p) * ncolumns;
+			for (j=p; j<(ncolumns-p); j++)
+			{
+				P4 = data[ iminuspxncolumns + (j-p)]; /* P4 = data[i-p][j-p] */
+				S4 = data[ iminuspxncolumns + j];     /* S4 = data[i-p][j]   */
+				P2 = data[ iminuspxncolumns + (j+p)]; /* P2 = data[i-p][j+p] */
+				S3 = data[ ixncolumns + (j-p)];       /* S3 = data[i][j-p]   */
+				S2 = data[ ixncolumns + (j+p)];       /* S2 = data[i][j+p]   */
+				P3 = data[ ipluspxncolumns + (j-p)];  /* P3 = data[i+p][j-p] */
+				S1 = data[ ipluspxncolumns + j];      /* S1 = data[i+p][j]   */
+				P1 = data[ ipluspxncolumns + (j+p)];  /* P1 = data[i+p][j+p] */
+				dhelp = 0.5*(P1+P3);
+				S1 = MAX(S1, dhelp) - dhelp;
+				dhelp = 0.5*(P1+P2);
+				S2 = MAX(S2, dhelp) - dhelp;
+				dhelp = 0.5*(P3+P4);
+				S3 = MAX(S3, dhelp) - dhelp;
+				dhelp = 0.5*(P2+P4);
+				S4 = MAX(S4, dhelp) - dhelp;
+				w[ixncolumns + j] = MIN(data[ixncolumns + j], 0.5 * (S1+S2+S3+S4) + 0.25 * (P1+P2+P3+P4));
+			}
+		}
+		for (i=p; i<(nrows-p); i++)
+		{
+			ixncolumns = i * ncolumns;
+			for (j=p; j<(ncolumns-p); j++)
+			{
+				data[ixncolumns + j] = w[ixncolumns + j];
+			}
+		}
+	}
+	free(w);
+}