python代替labelme生成imageData数据

 json格式，比如提取轮廓，不想手动打图像分割标签的可以用这个方法。

from labelme import PY2
from labelme import QT4
from labelme.logger import logger
import base64
import io
import numpy as np
from PIL import ExifTags
# import PIL.ExifTags
from PIL import Image
# import PIL.Image
# import PIL.ImageOps
from PIL import ImageOps
import os
import os.path as osp
import json


class MyEncoder(json.JSONEncoder):

    def default(self, obj):
        """
        只要检查到了是bytes类型的数据就把它转为str类型
        :param obj:
        :return:
        """
        if isinstance(obj, bytes):
            return str(obj, encoding='utf-8')
        return json.JSONEncoder.default(self, obj)


def apply_exif_orientation(image):
    try:
        exif = image._getexif()
    except AttributeError:
        exif = None

    if exif is None:
        return image

    exif = {
        ExifTags.TAGS[k]: v
        for k, v in exif.items()
        if k in ExifTags.TAGS
    }

    orientation = exif.get('Orientation', None)

    if orientation == 1:
        # do nothing
        return image
    elif orientation == 2:
        # left-to-right mirror
        return ImageOps.mirror(image)
    elif orientation == 3:
        # rotate 180
        return image.transpose(Image.ROTATE_180)
    elif orientation == 4:
        # top-to-bottom mirror
        return ImageOps.flip(image)
    elif orientation == 5:
        # top-to-left mirror
        return ImageOps.mirror(image.transpose(Image.ROTATE_270))
    elif orientation == 6:
        # rotate 270
        return image.transpose(Image.ROTATE_270)
    elif orientation == 7:
        # top-to-right mirror
        return ImageOps.mirror(image.transpose(Image.ROTATE_90))
    elif orientation == 8:
        # rotate 90
        return image.transpose(Image.ROTATE_90)
    else:
        return image
    
#@staticmethod
def load_image_file(filename):
    try:
        image_pil = Image.open(filename)
    except IOError:
        logger.error('Failed opening image file: {}'.format(filename))
        return

# apply orientation to image according to exif
    image_pil = apply_exif_orientation(image_pil)

    with io.BytesIO() as f:
        ext = osp.splitext(filename)[1].lower()
        if PY2 and QT4:
            format = 'PNG'
        elif ext in ['.jpg', '.jpeg']:
            format = 'JPEG'
        else:
            format = 'PNG'
        image_pil.save(f, format=format)
        f.seek(0)
        return f.read()

data = {}
path = './'
imageList=os.listdir(path)
print(imageList)

for imageName in imageList:
    if imageName.endswith('.jpg'):
        imageData = load_image_file(osp.join(path,imageName))
        imageData=base64.b64encode(imageData).decode('utf-8')    #此时imageData是unicode格式，需要转成str
        str1 = imageData.encode('gbk')
        print(str1)
        data["imageData"] = str1


with open('./1.json', 'w') as wf:
    json.dump(data, wf,cls=MyEncoder,indent=4)