Paddleocr数据增强调用逻辑

数据增强调用逻辑

以在ppocr/data/simple_dataset.py为例：

get_ext_data通过self.ops[:self.ext_op_transform_idx]获取配置文件中数据增强

 self.ops在def __init__(self, config, mode, logger, seed=None):中通过解析配置文件中'transforms'内容获取数据增强操作：

self.ops = create_operators(dataset_config['transforms'], global_config)

 然后调用 data = transform(data, load_data_ops)实现数据增强。

 def get_ext_data(self):
        ext_data_num = 0
        for op in self.ops:
            if hasattr(op, 'ext_data_num'):
                ext_data_num = getattr(op, 'ext_data_num')
                break
        load_data_ops = self.ops[:self.ext_op_transform_idx]
        ext_data = []

        while len(ext_data) < ext_data_num:
            file_idx = self.data_idx_order_list[np.random.randint(self.__len__(
            ))]
            data_line = self.data_lines[file_idx]
            data_line = data_line.decode('utf-8')
            substr = data_line.strip("\n").split(self.delimiter)
            file_name = substr[0]
            file_name = self._try_parse_filename_list(file_name)
            label = substr[1]
            img_path = os.path.join(self.data_dir, file_name)
            data = {'img_path': img_path, 'label': label}
            if not os.path.exists(img_path):
                continue
            with open(data['img_path'], 'rb') as f:
                img = f.read()
                data['image'] = img
            data = transform(data, load_data_ops)

            if data is None:
                continue
            if 'polys' in data.keys():
                if data['polys'].shape[1] != 4:
                    continue
            ext_data.append(data)
        return ext_data

数据增强实现的细节：

代码来自ppocr/data/imaug/__init__.py

1、trainsform函数将数据增强数组逐个对数据输出数据列表

def transform(data, ops=None):
    """ transform """
    if ops is None:
        ops = []
    for op in ops:
        data = op(data)
        if data is None:
            return None
    return data

op(data)为什么能进行数据增强：

 每一个op是eval(op_name)(**param)，eval() 函数将字符串 expression 解析为 Python 表达式，并在指定的命名空间中执行它。

def create_operators(op_param_list, global_config=None):
    """
    create operators based on the config

    Args:
        params(list): a dict list, used to create some operators
    """
    assert isinstance(op_param_list, list), ('operator config should be a list')
    ops = []
    for operator in op_param_list:
        assert isinstance(operator,
                          dict) and len(operator) == 1, "yaml format error"
        op_name = list(operator)[0]
        param = {} if operator[op_name] is None else operator[op_name]
        if global_config is not None:
            param.update(global_config)
        op = eval(op_name)(**param)
        ops.append(op)
    return ops

例如配置文件中的：

CopyPaste: null

通过ppocr/data/imaug/__init__.py，eval()可以调用CopyPaste实现数据增强

from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
from __future__ import unicode_literals

from .iaa_augment import IaaAugment
from .make_border_map import MakeBorderMap
from .make_shrink_map import MakeShrinkMap
from .random_crop_data import EastRandomCropData, RandomCropImgMask
from .make_pse_gt import MakePseGt

from .rec_img_aug import BaseDataAugmentation, RecAug, RecConAug, RecResizeImg, ClsResizeImg, \
    SRNRecResizeImg, GrayRecResizeImg, SARRecResizeImg, PRENResizeImg, \
    ABINetRecResizeImg, SVTRRecResizeImg, ABINetRecAug, VLRecResizeImg, SPINRecResizeImg, RobustScannerRecResizeImg, \
    RFLRecResizeImg, SVTRRecAug, ParseQRecAug
from .ssl_img_aug import SSLRotateResize
from .randaugment import RandAugment
from .copy_paste import CopyPaste
from .ColorJitter import ColorJitter
from .operators import *
from .label_ops import *

from .east_process import *
from .sast_process import *
from .pg_process import *
from .table_ops import *

from .vqa import *

from .fce_aug import *
from .fce_targets import FCENetTargets
from .ct_process import *
from .drrg_targets import DRRGTargets