RecogLMDBDataset

class mmocr.datasets.RecogLMDBDataset(ann_file='', img_color_type='color', metainfo=None, data_root='', data_prefix={'img_path': ''}, filter_cfg=None, indices=None, serialize_data=True, pipeline=[], test_mode=False, lazy_init=False, max_refetch=1000)

RecogLMDBDataset for text recognition.

The annotation format should be in lmdb format. The lmdb file should contain three keys: ‘num-samples’, ‘label-xxxxxxxxx’ and ‘image-xxxxxxxxx’, where ‘xxxxxxxxx’ is the index of the image. The value of ‘num-samples’ is the total number of images. The value of ‘label-xxxxxxx’ is the text label of the image, and the value of ‘image-xxxxxxx’ is the image data.

following keys: Each item fetched from this dataset will be a dict containing the following keys:

• img (ndarray): The loaded image.

• img_path (str): The image key.

• instances (list[dict]): The list of annotations for the image.

Parameters

• ann_file (str) – Annotation file path. Defaults to ‘’.

• img_color_type (str) – The flag argument for :func:mmcv.imfrombytes, which determines how the image bytes will be parsed. Defaults to ‘color’.

• metainfo (dict, optional) – Meta information for dataset, such as class information. Defaults to None.

• data_root (str) – The root directory for data_prefix and ann_file. Defaults to ‘’.

• data_prefix (dict) – Prefix for training data. Defaults to dict(img_path='').

• filter_cfg (dict, optional) – Config for filter data. Defaults to None.

• indices (int or Sequence[int], optional) – Support using first few data in annotation file to facilitate training/testing on a smaller dataset. Defaults to None which means using all data_infos.

• serialize_data (bool, optional) – Whether to hold memory using serialized objects, when enabled, data loader workers can use shared RAM from master process instead of making a copy. Defaults to True.

• pipeline (list, optional) – Processing pipeline. Defaults to [].

• test_mode (bool, optional) – test_mode=True means in test phase. Defaults to False.

• lazy_init (bool, optional) – Whether to load annotation during instantiation. In some cases, such as visualization, only the meta information of the dataset is needed, which is not necessary to load annotation file. RecogLMDBDataset can skip load annotations to save time by set lazy_init=False. Defaults to False.

• max_refetch (int, optional) – If RecogLMDBdataset.prepare_data get a None img. The maximum extra number of cycles to get a valid image. Defaults to 1000.

close()

Close lmdb environment.

load_data_list()

Load annotations from an annotation file named as self.ann_file

Returns

A list of annotation.

Return type

List[dict]

parse_data_info(raw_anno_info)

Parse raw annotation to target format.

Parameters

raw_anno_info (str) – One raw data information loaded from ann_file.

Returns

Parsed annotation.

Return type

(dict)

prepare_data(idx)

Get data processed by self.pipeline.

Parameters

idx (int) – The index of data_info.

Returns

Depends on self.pipeline.

Return type

Any