struct sift_keypoint_std *sift_read_keyslocation_from_file(char *filename, int *n) { struct sift_parameters* p = sift_assign_default_parameters(); int n_ori = p->n_ori; // 8 int n_hist = p->n_hist; // 4 int l = n_hist*n_hist*n_ori; int n_bins = p->n_bins; // read keypoints locations from a file and // save them into a sift_keypoints structure struct sift_keypoints* keys = sift_malloc_keypoints(); int flag = 0; // read coordinates sift_read_keypoints(keys, filename, n_hist, n_ori, n_bins, flag); // translate the sift_keypoints structure into a flat list *n = keys->size; struct sift_keypoint_std* k = xmalloc((*n)*sizeof(struct sift_keypoint_std)); for(int i = 0; i < keys->size; i++){ k[i].x = keys->list[i]->x; k[i].y = keys->list[i]->y; k[i].scale = keys->list[i]->sigma; k[i].orientation = keys->list[i]->theta; // 0 for(int j=0; j<l; j++){ k[i].descriptor[j] = keys->list[i]->descr[j]; // 0 } } sift_free_keypoints(keys); return k; }
/** @brief Extracts oriented keypoints (without description * * */ struct sift_keypoint_std* sift_compute_points(const float* x, int w, int h, int *n) { /** assign default parameters **/ struct sift_parameters* p = sift_assign_default_parameters(); /** Memory dynamic allocation */ // WARNING 5 lists of keypoints containing intermediary states of the algorithm struct sift_keypoints **kk = xmalloc(5*sizeof(struct sift_keypoints*)); for(int i = 0; i < 5; i++){ kk[i] = sift_malloc_keypoints(); } // WARNING 4 scalespace structure containing the DoG and Gaussian scalespace and the gradient struct sift_scalespace **ss = xmalloc(2*sizeof(struct sift_scalespace*)); /** Algorithm */ struct sift_keypoints* keys = sift_anatomy_without_description(x, w, h, p, ss, kk); /* Copy to a list of keypoints */ *n = keys->size; struct sift_keypoint_std* k = xmalloc((*n)*sizeof(*k)); for(int i = 0; i < keys->size; i++){ k[i].x = keys->list[i]->x; k[i].y = keys->list[i]->y; k[i].scale = keys->list[i]->sigma; k[i].orientation = keys->list[i]->theta; for(int j = 0; j < 128; j++){ k[i].descriptor[j] = 0; } } /* memory deallocation */ xfree(p); sift_free_keypoints(keys); for(int i = 0; i < 5; i++){ sift_free_keypoints(kk[i]); } xfree(kk); for(int i = 0; i < 2; i++){ sift_free_scalespace(ss[i]); } xfree(ss); return k; }
static struct sift_keypoints* sift_translate_standard_into_anatomy( const struct sift_keypoint_std* k, int n) { // load the default parameters are required struct sift_parameters* p = sift_assign_default_parameters(); float sigma_min = p->sigma_min; // 0.8 float delta_min = p->delta_min; // 0.5 int n_spo = p->n_spo; // 3 int n_ori = p->n_ori; // 8 int n_hist = p->n_hist; // 4 int n_bins = p->n_bins; // 36 struct sift_keypoints* keys = sift_malloc_keypoints(); for (int i = 0; i < n; i++) { struct keypoint* key = sift_malloc_keypoint(n_ori, n_hist, n_bins); /* reading the extremum continuous coordinates */ key->x = k[i].x; key->y = k[i].y; key->sigma = k[i].scale; key->theta = k[i].orientation; /* inferring the discrete coordinates in the scale-space grid */ // We look for the pair of integer (o,s) such that nspo*o+s is the nearest // to alpha = nspo * log( k[i].scale / sigma_min) /M_LN2 // with the constraint s=1,2,..,nspo. int o, s; int a = (int) (round(n_spo * log( k[i].scale / sigma_min) / M_LN2)); o = (a - 1) / n_spo; if (o > -1) { s = (a - 1) % n_spo + 1; } else { o = 0; s = 0; } key->o = o; key->s = s; key->i = (int)( key->x / ( delta_min * exp( key->o * M_LN2)) + 0.5 ); key->j = (int)( key->y / ( delta_min * exp( key->o * M_LN2)) + 0.5 ); sift_add_keypoint_to_list(key,keys); } return keys; }
void sift_find_ori_and_fill_descriptors(const float *x, int w, int h, struct sift_keypoint_std *k, int n) { struct sift_keypoints* keys = sift_translate_standard_into_anatomy(k, n); /** assign default parameters **/ struct sift_parameters* p = sift_assign_default_parameters(); /** algorithm */ sift_anatomy_orientation_and_description(x, w, h, p, keys); /* Copy back to the input flat list of keypoints */ for(int i = 0; i < keys->size; i++){ k[i].x = keys->list[i]->x; k[i].y = keys->list[i]->y; k[i].scale = keys->list[i]->sigma; k[i].orientation = keys->list[i]->theta; for(int j=0; j<128; j++){ k[i].descriptor[j] = (unsigned char)(keys->list[i]->descr[j]); } } }
int main(int argc, char **argv) { if((argc != 3)&&(argc != 5)){ print_usage(); return EXIT_FAILURE; } // Loading image int w, h; _myfloat* im = read_image_to_gray(argv[2], &w, &h); // load standard method parameter struct sift_parameters* p = sift_assign_default_parameters(); bool gauss_flag = true; if (argc == 5){ p->lambda_descr = atof(argv[argc-2]); gauss_flag = atoi(argv[argc-1]); } // load keypoints (ellipse) struct sift_keypoints *l = sift_malloc_keypoints(); sift_read_ellipses(l, argv[1], p->n_hist, p->n_ori, p->n_bins, 0); fprintf(stderr," after read"); estimate_scalespace_index(l, p); fprintf(stderr," after estimate scalespace index"); // scalespace, gradient, orientation and description ellipse_sift_anatomy_orientation_and_description(im, w, h, p, l, gauss_flag); fprintf(stderr," after ellipse index"); // printing ellipses fprintf_ellipses(stdout, l, 1); // memory deallocation sift_free_keypoints(l); free(im); return EXIT_SUCCESS; }
int main(int c, char *v[]) { // process input arguments if (c < 2) { print_help(v); return 1; } // optional arguments const char *output_file = pick_option(&c, &v, "o", "stdout"); bool binary = (bool) pick_option(&c, &v, "b", NULL); bool verbose = (bool) pick_option(&c, &v, "-verbose", NULL); int max_nb_pts = atoi(pick_option(&c, &v, "-max-nb-pts", "INT_MAX")); float thresh_dog = atof(pick_option(&c, &v, "-thresh-dog", "0.0133")); int ss_noct = atoi(pick_option(&c, &v, "-scale-space-noct", "8")); int ss_nspo = atoi(pick_option(&c, &v, "-scale-space-nspo", "3")); // initialise time struct timespec ts; portable_gettime(&ts); // define the rectangular region of interest (roi) int x, y, w, h; if (c == 2) { x = 0; y = 0; } else if (c == 6) { x = atoi(v[2]); y = atoi(v[3]); w = atoi(v[4]); h = atoi(v[5]); } else { print_help(v); return 1; } // read the roi in the input image GDALDatasetH hDataset; GDALAllRegister(); hDataset = GDALOpen( v[1], GA_ReadOnly ); if( hDataset == NULL ) { fprintf(stderr, "ERROR : can't open %s\n", v[1]); } GDALRasterBandH hBand; hBand = GDALGetRasterBand( hDataset, 1 ); float *roi; roi = (float *) CPLMalloc(sizeof(float)*w*h); GDALRasterIO( hBand, GF_Read, x, y, w, h, roi, w, h, GDT_Float32, 0, 0 ); GDALClose(hBand); GDALClose(hDataset); if (verbose) print_elapsed_time(&ts, "read ROI", 35); // prepare sift parameters struct sift_parameters* p = sift_assign_default_parameters(); p->C_DoG = thresh_dog; p->n_oct = ss_noct; p->n_spo = ss_nspo; // compute sift keypoints struct sift_scalespace **ss = (struct sift_scalespace**) malloc(4 * sizeof(struct sift_scalespace*)); struct sift_keypoints **kk = (struct sift_keypoints**) malloc(6 * sizeof(struct sift_keypoints*)); for (int i = 0; i < 6; i++) kk[i] = sift_malloc_keypoints(); struct sift_keypoints* kpts = sift_anatomy(roi, w, h, p, ss, kk); if (verbose) print_elapsed_time(&ts, "run SIFT", 35); // add (x, y) offset to keypoints coordinates for (int i = 0; i < kpts->size; i++) { kpts->list[i]->x += y; // in Ives' conventions x is the row index kpts->list[i]->y += x; } if (verbose) print_elapsed_time(&ts, "add offset", 35); // write to standard output FILE *f = fopen(output_file, "w"); fprintf_keypoints(f, kpts, max_nb_pts, binary, 1); fclose(f); if (verbose) print_elapsed_time(&ts, "write output", 35); // cleanup CPLFree(roi); sift_free_keypoints(kpts); for (int i = 0; i < 6; i++) sift_free_keypoints(kk[i]); free(kk); for (int i = 0; i < 4; i++) sift_free_scalespace(ss[i]); free(ss); free(p); return 0; }