COCO数据集训练格式转换成YOLO格式
COCO转YOLO：
⽐如coco2017train或coco2017val数据集中标注的⽬标(类别)位置在 Annotations 中以 (x, y, width, height) 来进⾏表⽰，x，y表⽰bbox左上⾓位置，width, height表⽰bbox的宽和⾼。⽽YOLO训练或者进⾏验证的时候读取的标注格式是以 (xmin, ymin, xmax, ymax)来进⾏表⽰，xmin, ymin表⽰bbox左上⾓位置， xmax, ymax表⽰bbox右下⾓位置。
所以将COCO标注格式（.json）转换成YOLO格式（.txt）并存储，⽐如转换val数据集的格式，其代码如下：
```python
import json
from collections import defaultdict
"""hyper parameters"""
json_file_path = '/home/wsy/data/coco2014/annotations/instances_val2014.json' images_dir_path = '/home/wsy/data/coco2014/val2014/'
皮肤暗疮
output_path = '/home/wsy/code/pytorch-YOLOv4/'
"""load json file"""
name_box_id = defaultdict(list)
id_name = dict()
投资公司经营范围with open(json_file_path, encoding='utf-8') as f:
吐泡泡的小鱼data = json.load(f)
annotations = data['annotations']
for ant in annotations:
id = ant['image_id']
name = '/home/wsy/data/coco2014/val2014/COCO_val2014_%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:
值得的经典句子cat = cat - 10
快乐英语第三册
elif cat >= 84 and cat <= 90:
cat = cat - 11
大学生实践报告name_box_id[name].append([ant['bbox'], cat])
"""write to txt"""
法规英文with open(output_path, 'w') as f:
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)
护发膜怎么使用f.write('\n')
