# scipy/scipy

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 /*--------------------------------------------------------------------*/ #include "Python.h" #define NO_IMPORT_ARRAY #include "numpy/noprefix.h" /* defined below */ void f_medfilt2(float*,float*,intp*,intp*); void d_medfilt2(double*,double*,intp*,intp*); void b_medfilt2(unsigned char*,unsigned char*,intp*,intp*); extern char *check_malloc (int); /* The QUICK_SELECT routine is based on Hoare's Quickselect algorithm, * with unrolled recursion. * Author: Thouis R. Jones, 2008 */ #define ELEM_SWAP(t, a, x, y) {register t temp = (a)[x]; (a)[x] = (a)[y]; (a)[y] = temp;} #define FIRST_LOWEST(x, y, z) (((x) < (y)) && ((x) < (z))) #define FIRST_HIGHEST(x, y, z) (((x) > (y)) && ((x) > (z))) #define LOWEST_IDX(a, x, y) (((a)[x] < (a)[y]) ? (x) : (y)) #define HIGHEST_IDX(a, x, y) (((a)[x] > (a)[y]) ? (x) : (y)) /* if (l is index of lowest) {return lower of mid,hi} else if (l is index of highest) {return higher of mid,hi} else return l */ #define MEDIAN_IDX(a, l, m, h) (FIRST_LOWEST((a)[l], (a)[m], (a)[h]) ? LOWEST_IDX(a, m, h) : (FIRST_HIGHEST((a)[l], (a)[m], (a)[h]) ? HIGHEST_IDX(a, m, h) : (l))) #define QUICK_SELECT(NAME, TYPE) \ TYPE NAME(TYPE arr[], int n) \ { \ int lo, hi, mid, md; \ int median_idx; \ int ll, hh; \ TYPE piv; \ \ lo = 0; hi = n-1; \ median_idx = (n - 1) / 2; /* lower of middle values for even-length arrays */ \ \ while (1) { \ if ((hi - lo) < 2) { \ if (arr[hi] < arr[lo]) ELEM_SWAP(TYPE, arr, lo, hi); \ return arr[median_idx]; \ } \ \ mid = (hi + lo) / 2; \ /* put the median of lo,mid,hi at position lo - this will be the pivot */ \ md = MEDIAN_IDX(arr, lo, mid, hi); \ ELEM_SWAP(TYPE, arr, lo, md); \ \ /* Nibble from each end towards middle, swapping misordered items */ \ piv = arr[lo]; \ for (ll = lo+1, hh = hi;; ll++, hh--) { \ while (arr[ll] < piv) ll++; \ while (arr[hh] > piv) hh--; \ if (hh < ll) break; \ ELEM_SWAP(TYPE, arr, ll, hh); \ } \ /* move pivot to top of lower partition */ \ ELEM_SWAP(TYPE, arr, hh, lo); \ /* set lo, hi for new range to search */ \ if (hh < median_idx) /* search upper partition */ \ lo = hh+1; \ else if (hh > median_idx) /* search lower partition */ \ hi = hh-1; \ else \ return piv; \ } \ } /* 2-D median filter with zero-padding on edges. */ #define MEDIAN_FILTER_2D(NAME, TYPE, SELECT) \ void NAME(TYPE* in, TYPE* out, intp* Nwin, intp* Ns) \ { \ int nx, ny, hN[2]; \ int pre_x, pre_y, pos_x, pos_y; \ int subx, suby, k, totN; \ TYPE *myvals, *fptr1, *fptr2, *ptr1, *ptr2; \ \ totN = Nwin[0] * Nwin[1]; \ myvals = (TYPE *) check_malloc( totN * sizeof(TYPE)); \ \ hN[0] = Nwin[0] >> 1; \ hN[1] = Nwin[1] >> 1; \ ptr1 = in; \ fptr1 = out; \ for (ny = 0; ny < Ns[0]; ny++) \ for (nx = 0; nx < Ns[1]; nx++) { \ pre_x = hN[1]; \ pre_y = hN[0]; \ pos_x = hN[1]; \ pos_y = hN[0]; \ if (nx < hN[1]) pre_x = nx; \ if (nx >= Ns[1] - hN[1]) pos_x = Ns[1] - nx - 1; \ if (ny < hN[0]) pre_y = ny; \ if (ny >= Ns[0] - hN[0]) pos_y = Ns[0] - ny - 1; \ fptr2 = myvals; \ ptr2 = ptr1 - pre_x - pre_y*Ns[1]; \ for (suby = -pre_y; suby <= pos_y; suby++) { \ for (subx = -pre_x; subx <= pos_x; subx++) \ *fptr2++ = *ptr2++; \ ptr2 += Ns[1] - (pre_x + pos_x + 1); \ } \ ptr1++; \ \ /* Zero pad */ \ for (k = (pre_x + pos_x + 1)*(pre_y + pos_y + 1); k < totN; k++) \ *fptr2++ = 0.0; \ \ /* *fptr1++ = median(myvals,totN); */ \ *fptr1++ = SELECT(myvals,totN); \ } \ free(myvals); \ } /* define quick_select for floats, doubles, and unsigned characters */ QUICK_SELECT(f_quick_select, float) QUICK_SELECT(d_quick_select, double) QUICK_SELECT(b_quick_select, unsigned char) /* define medfilt for floats, doubles, and unsigned characters */ MEDIAN_FILTER_2D(f_medfilt2, float, f_quick_select) MEDIAN_FILTER_2D(d_medfilt2, double, d_quick_select) MEDIAN_FILTER_2D(b_medfilt2, unsigned char, b_quick_select)
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