From 442eac315e4b8be19adab80fb7332d29f68c077c Mon Sep 17 00:00:00 2001
From: Gustaf Rydholm <gustaf.rydholm@gmail.com>
Date: Sun, 27 Jun 2021 20:25:25 +0200
Subject: Fixed bug in word pieces

---
 text_recognizer/data/iam_paragraphs.py   |  4 ++++
 text_recognizer/data/iam_preprocessor.py |  6 +++---
 text_recognizer/data/mappings.py         | 10 +++++++++-
 text_recognizer/data/transforms.py       | 13 +++++++++++--
 4 files changed, 27 insertions(+), 6 deletions(-)

(limited to 'text_recognizer/data')

diff --git a/text_recognizer/data/iam_paragraphs.py b/text_recognizer/data/iam_paragraphs.py
index 6022804..fe60e99 100644
--- a/text_recognizer/data/iam_paragraphs.py
+++ b/text_recognizer/data/iam_paragraphs.py
@@ -17,6 +17,7 @@ from text_recognizer.data.base_dataset import (
 )
 from text_recognizer.data.base_data_module import BaseDataModule, load_and_print_info
 from text_recognizer.data.emnist import emnist_mapping
+from text_recognizer.data.mappings import WordPieceMapping
 from text_recognizer.data.iam import IAM
 from text_recognizer.data.transforms import WordPiece
 
@@ -49,6 +50,9 @@ class IAMParagraphs(BaseDataModule):
         self.mapping, self.inverse_mapping, _ = emnist_mapping(
             extra_symbols=[NEW_LINE_TOKEN]
         )
+        if word_pieces:
+            self.mapping = WordPieceMapping()
+
         self.train_fraction = train_fraction
 
         self.dims = (1, IMAGE_HEIGHT, IMAGE_WIDTH)
diff --git a/text_recognizer/data/iam_preprocessor.py b/text_recognizer/data/iam_preprocessor.py
index b5f72da..506036e 100644
--- a/text_recognizer/data/iam_preprocessor.py
+++ b/text_recognizer/data/iam_preprocessor.py
@@ -89,9 +89,9 @@ class Preprocessor:
             self.lexicon = None
 
         if self.special_tokens is not None:
-            self.special_tokens += ("#", "*")
-            self.tokens += self.special_tokens
-            self.graphemes += self.special_tokens
+            special_tokens_ = (*self.special_tokens, "#", "*")
+            self.tokens += special_tokens_
+            self.graphemes += special_tokens_
 
         self.graphemes_to_index = {t: i for i, t in enumerate(self.graphemes)}
         self.tokens_to_index = {t: i for i, t in enumerate(self.tokens)}
diff --git a/text_recognizer/data/mappings.py b/text_recognizer/data/mappings.py
index 190febe..0d778b2 100644
--- a/text_recognizer/data/mappings.py
+++ b/text_recognizer/data/mappings.py
@@ -125,6 +125,9 @@ class WordPieceMapping(EmnistMapping):
             special_tokens,
         )
 
+    def __len__(self) -> int:
+        return len(self.wordpiece_processor.tokens)
+
     def get_token(self, index: Union[int, Tensor]) -> str:
         if (index := int(index)) <= self.wordpiece_processor.num_tokens:
             return self.wordpiece_processor.tokens[index]
@@ -132,7 +135,7 @@ class WordPieceMapping(EmnistMapping):
 
     def get_index(self, token: str) -> Tensor:
         if token in self.wordpiece_processor.tokens:
-            return torch.LongTensor(self.wordpiece_processor.tokens_to_index[token])
+            return torch.LongTensor([self.wordpiece_processor.tokens_to_index[token]])
         raise KeyError(f"Token ({token}) not found in inverse mapping.")
 
     def get_text(self, indices: Union[List[int], Tensor]) -> str:
@@ -147,3 +150,8 @@ class WordPieceMapping(EmnistMapping):
         text = "".join([self.mapping[i] for i in x])
         text = text.lower().replace(" ", "▁")
         return torch.LongTensor(self.wordpiece_processor.to_index(text))
+
+    def __getitem__(self, x: Union[str, int, Tensor]) -> Union[str, Tensor]:
+        if isinstance(x, str):
+            return self.get_index(x)
+        return self.get_token(x)
diff --git a/text_recognizer/data/transforms.py b/text_recognizer/data/transforms.py
index d0f1f35..66531a5 100644
--- a/text_recognizer/data/transforms.py
+++ b/text_recognizer/data/transforms.py
@@ -2,6 +2,7 @@
 from pathlib import Path
 from typing import Optional, Union, Sequence
 
+import torch
 from torch import Tensor
 
 from text_recognizer.data.mappings import WordPieceMapping
@@ -20,7 +21,7 @@ class WordPiece:
         prepend_wordsep: bool = False,
         special_tokens: Sequence[str] = ("<s>", "<e>", "<p>"),
         extra_symbols: Optional[Sequence[str]] = ("\n",),
-        max_len: int = 192,
+        max_len: int = 451,
     ) -> None:
         self.mapping = WordPieceMapping(
             num_features,
@@ -35,4 +36,12 @@ class WordPiece:
         self.max_len = max_len
 
     def __call__(self, x: Tensor) -> Tensor:
-        return self.mapping.emnist_to_wordpiece_indices(x)[: self.max_len]
+        y = self.mapping.emnist_to_wordpiece_indices(x)
+        if len(y) < self.max_len:
+            pad_len = self.max_len - len(y)
+            y = torch.cat(
+                (y, torch.LongTensor([self.mapping.get_index("<p>")] * pad_len))
+            )
+        else:
+            y = y[: self.max_len]
+        return y
-- 
cgit v1.2.3-70-g09d2