16 F2D** diffss(F2D** ss, int num, int intervals)
     17 {
     18     F2D** dss;
     19     int o, sizeM, sizeN, s, i, j;
     20     F2D *current, *in1, *in2;
     21
     22     dss = malloc(num*intervals*sizeof(F2D*));
     23
     24     int size, togo;
     25     for(o=0; o<num; o++)
     26     {
     27         for(s=0; s<(intervals-1); s++)
     28         {
     29             sizeM = ss[o*intervals+s]->height;
     30             sizeN = ss[o*intervals+s]->width;
     31
     32             //Amin: This loop is run as many times as imsmooth functions (36 for fullhd and 25 for vga) with the same M and N sizes
     33
     34             dss[o*intervals+s] = fMallocHandle(sizeM, sizeN);
     35
     36             current = dss[o*intervals+s];
     37             in1 = ss[o*intervals+s+1];
     38             in2 = ss[o*intervals+s];
     39
     40             /* Amin: Original implementation
     41             for(i=0; i<sizeM; i++)
     42             {
     43                 for(j=0; j<sizeN; j++)
     44                 {
     45                     subsref(current,i,j) = subsref(in1,i,j) - subsref(in2,i,j);
     46                 }
     47             }
     48             */
     49             /* Amin: Simpler implementation with one loop
     50             for(i=0; i<sizeM*sizeN; i++) {
     51                 asubsref(current,i) = asubsref(in1,i) - asubsref(in2,i);
     52             }
     53             */
     54             /* Amin: simpler implementation with 8 loop unrolling
     55              */
     56             for(i=0; i<sizeM*sizeN; i=i+8) {
     57                 togo = sizeM*sizeN - i;
     58                 size = (togo > 8) ? 8 : togo;
     59
     60                 for (j=0; j<size; j++)
     61                     asubsref(current,i+j) = asubsref(in1,i+j) - asubsref(in2,i+j);
     62             }
     63         }
     64     }
     65
     66     return dss;
     67 }
     68
     69
     70