initial commit

cclabling.h

@@ -0,0 +1,136 @@
+/*
+ * This file is part of the loccorr project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+//#define TESTMSGS
+
+#ifdef TESTMSGS
+#define TEST(...) printf(__VA_ARGS__)
+#else
+#define TEST(...)
+#endif
+
+size_t Nmax = W*H/4; // max number of 4-connected labels
+size_t *assoc = MALLOC(size_t, Nmax); // allocate memory for "remark" array
+size_t last_assoc_idx = 1; // last index filled in assoc array
+// was: 35
+// check table and rename all "oldval" into "newval"
+inline void remark(size_t newval, size_t oldval){
+    TEST("\tnew = %zd, old=%zd; ", newval, oldval);
+    // find the least values
+    do{newval = assoc[newval];}while(assoc[newval] != newval);
+    do{oldval = assoc[oldval];}while(assoc[oldval] != oldval);
+    TEST("\trealnew = %zd, realold=%zd ", newval, oldval);
+    // now change larger value to smaller
+    if(newval > oldval){
+        assoc[newval] = oldval;
+        TEST("change %zd to %zd\n", newval, oldval);
+    }else{
+        assoc[oldval] = newval;
+        TEST("change %zd to %zd\n", oldval, newval);
+    }
+}
+
+for(int y = 0; y < H; ++y){
+    bool found = false;
+    size_t *ptr = &labels[y*W];
+    size_t curmark = 0; // mark of pixel to the left
+    for(int x = 0; x < W; ++x, ++ptr){
+        if(!*ptr){found = false; continue;} // empty pixel
+        size_t U = (y) ? ptr[-W] : 0; // upper mark
+        if(found){ // there's a pixel to the left
+            if(U && U != curmark){ // meet old mark -> remark one of them in assoc[]
+                TEST("(%d, %d): remark %zd --> %zd\n", x, y, U, curmark);
+                remark(U, curmark);
+                curmark = U; // change curmark to upper mark (to reduce further checks)
+            }
+        }else{ // new mark -> change curmark
+            found = true;
+            if(U) curmark = U; // current mark will copy upper value
+            else{ // current mark is new value
+                curmark = last_assoc_idx++;
+                assoc[curmark] = curmark;
+                TEST("(%d, %d): new mark=%zd\n", x, y, curmark);
+            }
+        }
+        *ptr = curmark;
+    }
+}
+size_t *indexes = MALLOC(size_t, last_assoc_idx); // new indexes
+size_t cidx = 1;
+TEST("\n\n\nRebuild indexes\n\n");
+for(size_t i = 1; i < last_assoc_idx; ++i){
+    TEST("%zd\t%zd ",i,assoc[i]);
+    // search new index
+    register size_t realnew = i, newval = 0;
+    do{
+        realnew = assoc[realnew];
+        TEST("->%zd ", realnew);
+        if(indexes[realnew]){ // find least index
+            newval = indexes[realnew];
+            TEST("real: %zd ", newval);
+            break;
+        }
+    }while(assoc[realnew] != realnew);
+    if(newval){
+        TEST(" ==> %zd\n", newval);
+        indexes[i] = newval;
+        continue;
+    }
+    TEST("new index %zd\n", cidx);
+    // enter next label
+    indexes[i] = cidx++;
+}
+/*
+// rebuild indexes
+for(size_t i = 1; i < last_assoc_idx; ++i){
+    printf("%zd\t%zd ",i,assoc[i]);
+    if(i == assoc[i]){
+        if(i == cidx){
+            printf("- keep\n");
+        }else{
+            printf("- change to %zd\n", cidx);
+            size_t _2change = assoc[i];
+            assoc[i] = cidx;
+            for(size_t j = i+1; j < last_assoc_idx; ++j){
+                if(assoc[j] == _2change){
+                    printf("\t%zd\t%zd -> %zd\n", j, assoc[j], cidx);
+                    assoc[j] = cidx;
+                }
+            }
+        }
+        ++cidx;
+    }else printf("\n");
+}*/
+
+--cidx; // cidx now is amount of detected objects
+DBG("amount after rebuild: %zd", cidx);
+
+#ifdef TESTMSGS
+printf("\n\n\nI\tASS[I]\tIDX[I]\n");
+for(size_t i = 1; i < last_assoc_idx; ++i)
+    printf("%zd\t%zd\t%zd\n",i,assoc[i],indexes[i]);
+#endif
+
+int wh = W*H;
+OMP_FOR()
+for(int i = 0; i < wh; ++i) labels[i] = indexes[labels[i]];
+
+if(Nobj) *Nobj = cidx;
+
+FREE(assoc);
+FREE(indexes);