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authorGustaf Rydholm <gustaf.rydholm@gmail.com>2022-09-27 23:11:06 +0200
committerGustaf Rydholm <gustaf.rydholm@gmail.com>2022-09-27 23:11:06 +0200
commit9c7dbb9ca70858b870f74ecf595d3169f0cbc711 (patch)
treec342e2c004bb75571a380ef2805049a8fcec3fcc /text_recognizer/data/mappings/emnist.py
parent9b8e14d89f0ef2508ed11f994f73af624155fe1d (diff)
Rename mapping to tokenizer
Diffstat (limited to 'text_recognizer/data/mappings/emnist.py')
-rw-r--r--text_recognizer/data/mappings/emnist.py78
1 files changed, 0 insertions, 78 deletions
diff --git a/text_recognizer/data/mappings/emnist.py b/text_recognizer/data/mappings/emnist.py
deleted file mode 100644
index 331976e..0000000
--- a/text_recognizer/data/mappings/emnist.py
+++ /dev/null
@@ -1,78 +0,0 @@
-"""Emnist mapping."""
-import json
-from pathlib import Path
-from typing import Dict, List, Optional, Sequence, Tuple, Union
-
-import torch
-from torch import Tensor
-
-ESSENTIALS_FILENAME = Path(__file__).parents[0].resolve() / "emnist_essentials.json"
-
-
-class EmnistMapping:
- """Mapping for EMNIST labels."""
-
- def __init__(
- self,
- extra_symbols: Optional[Sequence[str]] = None,
- lower: bool = True,
- ) -> None:
- self.extra_symbols = set(extra_symbols) if extra_symbols is not None else None
- self.mapping, self.inverse_mapping, self.input_size = self._load_mapping()
- if lower:
- self._to_lower()
-
- def __len__(self) -> int:
- return len(self.mapping)
-
- @property
- def num_classes(self) -> int:
- return self.__len__()
-
- def _load_mapping(self) -> Tuple[List, Dict[str, int], List[int]]:
- """Return the EMNIST mapping."""
- with ESSENTIALS_FILENAME.open() as f:
- essentials = json.load(f)
- mapping = list(essentials["characters"])
- if self.extra_symbols is not None:
- mapping += self.extra_symbols
- inverse_mapping = {v: k for k, v in enumerate(mapping)}
- input_shape = essentials["input_shape"]
- return mapping, inverse_mapping, input_shape
-
- def _to_lower(self) -> None:
- """Converts mapping to lowercase letters only."""
-
- def _filter(x: int) -> int:
- if 40 <= x:
- return x - 26
- return x
-
- self.inverse_mapping = {v: _filter(k) for k, v in enumerate(self.mapping)}
- self.mapping = [c for c in self.mapping if not c.isupper()]
-
- def get_token(self, index: Union[int, Tensor]) -> str:
- """Returns token for index value."""
- if (index := int(index)) <= len(self.mapping):
- return self.mapping[index]
- raise KeyError(f"Index ({index}) not in mapping.")
-
- def get_index(self, token: str) -> Tensor:
- """Returns index value of token."""
- if token in self.inverse_mapping:
- return torch.LongTensor([self.inverse_mapping[token]])
- raise KeyError(f"Token ({token}) not found in inverse mapping.")
-
- def get_text(self, indices: Union[List[int], Tensor]) -> str:
- """Returns the text from a list of indices."""
- if isinstance(indices, Tensor):
- indices = indices.tolist()
- return "".join([self.mapping[index] for index in indices])
-
- def get_indices(self, text: str) -> Tensor:
- """Returns tensor of indices for a string."""
- return Tensor([self.inverse_mapping[token] for token in text])
-
- def __getitem__(self, x: Union[int, Tensor]) -> str:
- """Returns text for a list of indices."""
- return self.get_token(x)