--- a
+++ b/YOLO/coco_annotation.py
@@ -0,0 +1,52 @@
+import json
+from collections import defaultdict
+
+name_box_id = defaultdict(list)
+id_name = dict()
+f = open(
+    "mscoco2017/annotations/instances_train2017.json",
+    encoding='utf-8')
+data = json.load(f)
+
+annotations = data['annotations']
+for ant in annotations:
+    id = ant['image_id']
+    name = 'mscoco2017/train2017/%012d.jpg' % id
+    cat = ant['category_id']
+
+    if cat >= 1 and cat <= 11:
+        cat = cat - 1
+    elif cat >= 13 and cat <= 25:
+        cat = cat - 2
+    elif cat >= 27 and cat <= 28:
+        cat = cat - 3
+    elif cat >= 31 and cat <= 44:
+        cat = cat - 5
+    elif cat >= 46 and cat <= 65:
+        cat = cat - 6
+    elif cat == 67:
+        cat = cat - 7
+    elif cat == 70:
+        cat = cat - 9
+    elif cat >= 72 and cat <= 82:
+        cat = cat - 10
+    elif cat >= 84 and cat <= 90:
+        cat = cat - 11
+
+    name_box_id[name].append([ant['bbox'], cat])
+
+f = open('train.txt', 'w')
+for key in name_box_id.keys():
+    f.write(key)
+    box_infos = name_box_id[key]
+    for info in box_infos:
+        x_min = int(info[0][0])
+        y_min = int(info[0][1])
+        x_max = x_min + int(info[0][2])
+        y_max = y_min + int(info[0][3])
+
+        box_info = " %d,%d,%d,%d,%d" % (
+            x_min, y_min, x_max, y_max, int(info[1]))
+        f.write(box_info)
+    f.write('\n')
+f.close()