1 files changed, 53 insertions, 0 deletions

diff --git a/SD-VBS/benchmarks/sift/src/c/diffss.c b/SD-VBS/benchmarks/sift/src/c/diffss.c
new file mode 100644
index 0000000..683cbe7
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+++ b/SD-VBS/benchmarks/sift/src/c/diffss.c
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+/********************************
+Author: Sravanthi Kota Venkata
+********************************/
+
+#include "sift.h"
+
+/**
+    DIFFSS  Difference of scale space
+    Returns a scale space DSS obtained by subtracting
+    consecutive levels of the scale space SS.
+
+    In SIFT, this function is used to compute the difference of
+    Gaussian scale space from the Gaussian scale space of an image.
+**/
+
+F2D** diffss(F2D** ss, int num, int intervals)
+{
+    F2D** dss;
+    int o, sizeM, sizeN, s, i, j; 
+    F2D *current, *in1, *in2;
+
+    dss = malloc(num*intervals*sizeof(F2D*));
+
+    for(o=0; o<num; o++)
+    {
+        for(s=0; s<(intervals-1); s++)
+        {
+            sizeM = ss[o*intervals+s]->height;
+            sizeN = ss[o*intervals+s]->width;
+
+            dss[o*intervals+s] = fMallocHandle(sizeM, sizeN);
+
+            current = dss[o*intervals+s];
+            in1 = ss[o*intervals+s+1];
+            in2 = ss[o*intervals+s];
+            
+            for(i=0; i<sizeM; i++)
+            {
+                for(j=0; j<sizeN; j++)
+                {
+                    subsref(current,i,j) = subsref(in1,i,j) - subsref(in2,i,j);
+                }
+            }
+        }
+    }
+
+    return dss;
+
+}
+
+
+
+