nlpaug.augmenter.char.ocr

Augmenter that apply ocr error simulation to textual input.

class nlpaug.augmenter.char.ocr.OcrAug(name='OCR_Aug', aug_char_min=2, aug_char_max=10, aug_char_p=0.3, aug_word_p=0.3, aug_word_min=1, aug_word_max=10, stopwords=None, tokenizer=None, reverse_tokenizer=None, verbose=0, stopwords_regex=None, min_char=1, dict_of_path=None)[source]

Bases: nlpaug.augmenter.char.char_augmenter.CharAugmenter

Augmenter that simulate ocr error by random values. For example, OCR may recognize I as 1 incorrectly. Pre-defined OCR mapping is leveraged to replace character by possible OCR error.

Parameters:
  • aug_char_p (float) – Percentage of character (per token) will be augmented.
  • aug_char_min (int) – Minimum number of character will be augmented.
  • aug_char_max (int) – Maximum number of character will be augmented. If None is passed, number of augmentation is calculated via aup_char_p. If calculated result from aug_char_p is smaller than aug_char_max, will use calculated result from aup_char_p. Otherwise, using aug_max.
  • aug_word_p (float) – Percentage of word will be augmented.
  • aug_word_min (int) – Minimum number of word will be augmented.
  • aug_word_max (int) – Maximum number of word will be augmented. If None is passed, number of augmentation is calculated via aup_word_p. If calculated result from aug_word_p is smaller than aug_word_max, will use calculated result from aug_word_p. Otherwise, using aug_max.
  • min_char (int) – If word less than this value, do not draw word for augmentation
  • stopwords (list) – List of words which will be skipped from augment operation.
  • stopwords_regex (str) – Regular expression for matching words which will be skipped from augment operation.
  • tokenizer (func) – Customize tokenization process
  • reverse_tokenizer (func) – Customize reverse of tokenization process
  • dict_of_path (obj) – Use pre-defined dictionary by default. Pass either file path of dict to use custom mapping.
  • name (str) – Name of this augmenter
>>> import nlpaug.augmenter.char as nac
>>> aug = nac.OcrAug()
augment(data, n=1, num_thread=1)
Parameters:
  • data (object/list) – Data for augmentation. It can be list of data (e.g. list of string or numpy) or single element (e.g. string or numpy). Numpy format only supports audio or spectrogram data. For text data, only support string or list of string.
  • n (int) – Default is 1. Number of unique augmented output. Will be force to 1 if input is list of data
  • num_thread (int) – Number of thread for data augmentation. Use this option when you are using CPU and n is larger than 1
Returns:

Augmented data

>>> augmented_data = aug.augment(data)