Dictionary¶

class mmocr.models.common.Dictionary(dict_file, with_start=False, with_end=False, same_start_end=False, with_padding=False, with_unknown=False, start_token='<BOS>', end_token='<EOS>', start_end_token='<BOS/EOS>', padding_token='<PAD>', unknown_token='<UKN>')[source]¶

The class generates a dictionary for recognition. It pre-defines four special tokens: start_token, end_token, pad_token, and unknown_token, which will be sequentially placed at the end of the dictionary when their corresponding flags are True.

Parameters

dict_file (str) – The path of Character dict file which a single character must occupies a line.
with_start (bool) – The flag to control whether to include the start token. Defaults to False.
with_end (bool) – The flag to control whether to include the end token. Defaults to False.
same_start_end (bool) – The flag to control whether the start token and end token are the same. It only works when both with_start and with_end are True. Defaults to False.
with_padding (bool) – The padding token may represent more than a padding. It can also represent tokens like the blank token in CTC or the background token in SegOCR. Defaults to False.
with_unknown (bool) – The flag to control whether to include the unknown token. Defaults to False.
start_token (str) – The start token as a string. Defaults to ‘<BOS>’.
end_token (str) – The end token as a string. Defaults to ‘<EOS>’.
start_end_token (str) – The start/end token as a string. if start and end is the same. Defaults to ‘<BOS/EOS>’.
padding_token (str) – The padding token as a string. Defaults to ‘<PAD>’.
unknown_token (str, optional) – The unknown token as a string. If it’s set to None and with_unknown is True, the unknown token will be skipped when converting string to index. Defaults to ‘<UKN>’.

Return type

None

char2idx(char, strict=True)[source]¶

Convert a character to an index via Dictionary.dict.

Parameters

char (str) – The character to convert to index.
strict (bool) – The flag to control whether to raise an exception when the character is not in the dictionary. Defaults to True.

Returns

The index of the character.

Return type

int

property dict: list¶

Returns a list of characters to recognize, where special tokens are counted.

Type: list

idx2str(index)[source]¶

Convert a list of index to string.

Parameters: index (list[int]) – The list of indexes to convert to string.
Returns: The converted string.
Return type: str

property num_classes: int¶

Number of output classes. Special tokens are counted.

Type: int

str2idx(string)[source]¶

Convert a string to a list of indexes via Dictionary.dict.

Parameters: string (str) – The string to convert to indexes.
Returns: The list of indexes of the string.
Return type: list