目錄
摘要
Object Instance 類型的标注格式
1、整體JSON檔案格式
2、annotations字段
3、categories字段
Labelme轉COCO的代碼:
COCO的 全稱是Common Objects in COntext,是微軟團隊提供的一個可以用來進行圖像識别的資料集。MS COCO資料集中的圖像分為訓練、驗證和測試集。COCO通過在Flickr上搜尋80個對象類别和各種場景類型來收集圖像,其使用了亞馬遜的Mechanical Turk(AMT)。
COCO資料集現在有3種标注類型:object instances(目标執行個體), object keypoints(目标上的關鍵點), and image captions(看圖說話)。本文着重介紹object instances。
Object Instance這種格式的檔案從頭至尾按照順序分為以下段落:
{
"info": info,
"licenses": [license],
"images": [image],
"annotations": [annotation],
"categories": [category]
}
annotations字段是包含多個annotation執行個體的一個數組,annotation類型本身又包含了一系列的字段,如這個目标的category id和segmentation mask。segmentation格式取決于這個執行個體是一個單個的對象(即iscrowd=0,将使用polygons格式)還是一組對象(即iscrowd=1,将使用RLE格式)。bbox是存放的物體标注資訊,與VOC格式不同,COCO裡面存儲的格式是[左上角x坐标,左上角y坐标,物體的寬,物體的長],這點需要注意。如下所示:
annotation{
"id": int,
"image_id": int,
"category_id": int,
"segmentation": RLE or [polygon],
"area": float,
"bbox": [x,y,width,height],
"iscrowd": 0 or 1,
注意,單個的對象(iscrowd=0)可能需要多個polygon來表示,比如這個對象在圖像中被擋住了。而iscrowd=1時(将标注一組對象,比如一群人)的segmentation使用的就是RLE格式。
另外,每個對象(不管是iscrowd=0還是iscrowd=1)都會有一個矩形框bbox ,矩形框左上角的坐标和矩形框的長寬會以數組的形式提供,數組第一個元素就是左上角的橫坐标值。
area是area of encoded masks。
最後,annotation結構中的categories字段存儲的是目前對象所屬的category的id,以及所屬的supercategory的name。
下面是從instances_val2017.json檔案中摘出的一個annotation的執行個體:
"segmentation": [[510.66,423.01,511.72,420.03,510.45,416.0,510.34,413.02,510.77,410.26,\
510.77,407.5,510.34,405.16,511.51,402.83,511.41,400.49,510.24,398.16,509.39,\
397.31,504.61,399.22,502.17,399.64,500.89,401.66,500.47,402.08,499.09,401.87,\
495.79,401.98,490.59,401.77,488.79,401.77,485.39,398.58,483.9,397.31,481.56,\
396.35,478.48,395.93,476.68,396.03,475.4,396.77,473.92,398.79,473.28,399.96,\
473.49,401.87,474.56,403.47,473.07,405.59,473.39,407.71,476.68,409.41,479.23,\
409.73,481.56,410.69,480.4,411.85,481.35,414.93,479.86,418.65,477.32,420.03,\
476.04,422.58,479.02,422.58,480.29,423.01,483.79,419.93,486.66,416.21,490.06,\
415.57,492.18,416.85,491.65,420.24,492.82,422.9,493.56,424.39,496.43,424.6,\
498.02,423.01,498.13,421.31,497.07,420.03,497.07,415.15,496.33,414.51,501.1,\
411.96,502.06,411.32,503.02,415.04,503.33,418.12,501.1,420.24,498.98,421.63,\
500.47,424.39,505.03,423.32,506.2,421.31,507.69,419.5,506.31,423.32,510.03,\
423.01,510.45,423.01]],
"area": 702.1057499999998,
"iscrowd": 0,
"image_id": 289343,
"bbox": [473.07,395.93,38.65,28.67],
"category_id": 18,
"id": 1768
},
categories是一個包含多個category執行個體的數組,而category結構體描述如下:
"name": str,
"supercategory": str,
從instances_val2017.json檔案中摘出的2個category執行個體如下所示:
"supercategory": "person",
"id": 1,
"name": "person"
"supercategory": "vehicle",
"id": 2,
"name": "bicycle"
# -*- coding:utf-8 -*-
# !/usr/bin/env python
import json
from labelme import utils
import numpy as np
import glob
import PIL.Image
labels={'一次性快餐盒':1,'書籍紙張':2,'充電寶':3,'剩飯剩菜':4,'包':5,
'垃圾桶':6,'塑膠器皿':7,'塑膠玩具':8,'塑膠衣架':9,'大骨頭':10,'幹電池':11,
'快遞紙袋':12,'插頭電線':13,'舊衣服':14,'易拉罐':15,'枕頭':16,'果皮果肉':17,'毛絨玩具':18,
'污損塑膠':19,'污損用紙':20,'洗護用品':21,'煙蒂':22,'牙簽':23,'玻璃器皿':24,'砧闆':25,
'筷子':26,'紙盒紙箱':27,'花盆':28,'茶葉渣':29,'菜幫菜葉':30,'蛋殼':31,'調料瓶':32,
'軟膏':33,'過期藥物':34,'酒瓶':35,'金屬廚具':36,'金屬器皿':37,'金屬食品罐':38,'鍋':39,
'陶瓷器皿':40,'鞋':41,'食用油桶':42,'飲料瓶':43,'魚骨':44}
class MyEncoder(json.JSONEncoder):
def default(self, obj):
if isinstance(obj, np.integer):
return int(obj)
elif isinstance(obj, np.floating):
return float(obj)
elif isinstance(obj, np.ndarray):
return obj.tolist()
else:
return super(MyEncoder, self).default(obj)
class labelme2coco(object):
def __init__(self, labelme_json=[], save_json_path='./tran.json'):
'''
:param labelme_json: 所有labelme的json檔案路徑組成的清單
:param save_json_path: json儲存位置
self.labelme_json = labelme_json
self.save_json_path = save_json_path
self.images = []
self.categories = []
self.annotations = []
# self.data_coco = {}
self.label = []
self.annID = 1
self.height = 0
self.width = 0
self.save_json()
def data_transfer(self):
for num, json_file in enumerate(self.labelme_json):
imagePath=json_file.split('.')[0]+'.jpg'
imageName=imagePath.split('\\')[-1]
print(imageName)
with open(json_file, 'r') as fp:
data = json.load(fp) # 加載json檔案
self.images.append(self.image(data, num,imageName))
for shapes in data['shapes']:
label = shapes['label']
if label not in self.label:
self.categories.append(self.categorie(label))
self.label.append(label)
points = shapes['points'] # 這裡的point是用rectangle标注得到的,隻有兩個點,需要轉成四個點
# points.append([points[0][0],points[1][1]])
# points.append([points[1][0],points[0][1]])
self.annotations.append(self.annotation(points, label, num))
self.annID += 1
def image(self, data, num,imagePath):
image = {}
img = utils.img_b64_to_arr(data['imageData']) # 解析原圖檔資料
# img=io.imread(data['imagePath']) # 通過圖檔路徑打開圖檔
# img = cv2.imread(data['imagePath'], 0)
height, width = img.shape[:2]
img = None
image['height'] = height
image['width'] = width
image['id'] = num + 1
# image['file_name'] = data['imagePath'].split('/')[-1]
image['file_name'] = imagePath
self.height = height
self.width = width
return image
def categorie(self, label):
categorie = {}
categorie['supercategory'] = 'Cancer'
categorie['id'] = labels[label] # 0 預設為背景
categorie['name'] = label
return categorie
def annotation(self, points, label, num):
annotation = {}
annotation['segmentation'] = [list(np.asarray(points).flatten())]
annotation['iscrowd'] = 0
annotation['image_id'] = num + 1
# annotation['bbox'] = str(self.getbbox(points)) # 使用list儲存json檔案時報錯(不知道為什麼)
# list(map(int,a[1:-1].split(','))) a=annotation['bbox'] 使用該方式轉成list
annotation['bbox'] = list(map(float, self.getbbox(points)))
annotation['area'] = annotation['bbox'][2] * annotation['bbox'][3]
# annotation['category_id'] = self.getcatid(label)
annotation['category_id'] = self.getcatid(label) # 注意,源代碼預設為1
print(label,annotation['category_id'])
annotation['id'] = self.annID
return annotation
def getcatid(self, label):
for categorie in self.categories:
if label == categorie['name']:
return categorie['id']
return 1
def getbbox(self, points):
# img = np.zeros([self.height,self.width],np.uint8)
# cv2.polylines(img, [np.asarray(points)], True, 1, lineType=cv2.LINE_AA) # 畫邊界線
# cv2.fillPoly(img, [np.asarray(points)], 1) # 畫多邊形 内部像素值為1
polygons = points
mask = self.polygons_to_mask([self.height, self.width], polygons)
return self.mask2box(mask)
def mask2box(self, mask):
'''從mask反算出其邊框
mask:[h,w] 0、1組成的圖檔
1對應對象,隻需計算1對應的行列号(左上角行列号,右下角行列号,就可以算出其邊框)
# np.where(mask==1)
index = np.argwhere(mask == 1)
rows = index[:, 0]
clos = index[:, 1]
# 解析左上角行列号
left_top_r = np.min(rows) # y
left_top_c = np.min(clos) # x
# 解析右下角行列号
right_bottom_r = np.max(rows)
right_bottom_c = np.max(clos)
# return [(left_top_r,left_top_c),(right_bottom_r,right_bottom_c)]
# return [(left_top_c, left_top_r), (right_bottom_c, right_bottom_r)]
# return [left_top_c, left_top_r, right_bottom_c, right_bottom_r] # [x1,y1,x2,y2]
return [left_top_c, left_top_r, right_bottom_c - left_top_c,
right_bottom_r - left_top_r] # [x1,y1,w,h] 對應COCO的bbox格式
def polygons_to_mask(self, img_shape, polygons):
mask = np.zeros(img_shape, dtype=np.uint8)
mask = PIL.Image.fromarray(mask)
xy = list(map(tuple, polygons))
PIL.ImageDraw.Draw(mask).polygon(xy=xy, outline=1, fill=1)
mask = np.array(mask, dtype=bool)
return mask
def data2coco(self):
data_coco = {}
data_coco['images'] = self.images
data_coco['categories'] = self.categories
data_coco['annotations'] = self.annotations
return data_coco
def save_json(self):
self.data_transfer()
self.data_coco = self.data2coco()
# 儲存json檔案
json.dump(self.data_coco, open(self.save_json_path, 'w'), indent=4, cls=MyEncoder) # indent=4 更加美觀顯示
labelme_json = glob.glob('D:/HWLabelme/*.json')
from sklearn.model_selection import train_test_split
trainval_files, test_files = train_test_split(labelme_json, test_size=0.2, random_state=55)
labelme2coco(trainval_files, 'instances_train2017.json')
labelme2coco(test_files, 'instances_val2017.json')