PARP Research Group

Universidad de Murcia

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src/qvip/fast-C-src-2.1/nonmax.cpp #include <stdlib.h> #include "fast.h" #define Compare(X, Y) ((X)>=(Y)) xy* nonmax_suppression(const xy* corners, const int* scores, int num_corners, int* ret_num_nonmax) { int num_nonmax=0; int last_row; int* row_start; int i, j; xy* ret_nonmax; const int sz = (int)num_corners; /*Point above points (roughly) to the pixel above the one of interest, if there is a feature there.*/ int point_above = 0; int point_below = 0; if(num_corners < 1) { *ret_num_nonmax = 0; return 0; } ret_nonmax = (xy*)malloc(num_corners * sizeof(xy)); /* Find where each row begins (the corners are output in raster scan order). A beginning of -1 signifies that there are no corners on that row. */ last_row = corners[num_corners-1].y; row_start = (int*)malloc((last_row+1)*sizeof(int)); for(i=0; i < last_row+1; i++) row_start[i] = -1; { int prev_row = -1; for(i=0; i< num_corners; i++) if(corners[i].y != prev_row) { row_start[corners[i].y] = i; prev_row = corners[i].y; } } for(i=0; i < sz; i++) { int score = scores[i]; xy pos = corners[i]; /*Check left */ if(i > 0) if(corners[i-1].x == pos.x-1 && corners[i-1].y == pos.y && Compare(scores[i-1], score)) continue; /*Check right*/ if(i < (sz - 1)) if(corners[i+1].x == pos.x+1 && corners[i+1].y == pos.y && Compare(scores[i+1], score)) continue; /*Check above (if there is a valid row above)*/ if(pos.y != 0 && row_start[pos.y - 1] != -1) { /*Make sure that current point_above is one row above.*/ if(corners[point_above].y < pos.y - 1) point_above = row_start[pos.y-1]; /*Make point_above point to the first of the pixels above the current point, if it exists.*/ for(; corners[point_above].y < pos.y && corners[point_above].x < pos.x - 1; point_above++) {} for(j=point_above; corners[j].y < pos.y && corners[j].x <= pos.x + 1; j++) { int x = corners[j].x; if( (x == pos.x - 1 || x ==pos.x || x == pos.x+1) && Compare(scores[j], score)) goto cont; } } /*Check below (if there is anything below)*/ if(pos.y != last_row && row_start[pos.y + 1] != -1 && point_below < sz) /*Nothing below*/ { if(corners[point_below].y < pos.y + 1) point_below = row_start[pos.y+1]; /* Make point below point to one of the pixels belowthe current point, if it exists.*/ for(; point_below < sz && corners[point_below].y == pos.y+1 && corners[point_below].x < pos.x - 1; point_below++) {} for(j=point_below; j < sz && corners[j].y == pos.y+1 && corners[j].x <= pos.x + 1; j++) { int x = corners[j].x; if( (x == pos.x - 1 || x ==pos.x || x == pos.x+1) && Compare(scores[j],score)) goto cont; } } ret_nonmax[num_nonmax++] = corners[i]; cont: ; } free(row_start); *ret_num_nonmax = num_nonmax; return ret_nonmax; }

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