From fc884dd8fb48d11b37527df3c897c819f7eaeeeb Mon Sep 17 00:00:00 2001
From: Gustaf Rydholm <gustaf.rydholm@gmail.com>
Date: Sun, 5 Dec 2021 20:24:30 +0100
Subject: Update conv transformer with inheritance from base network

---
 text_recognizer/networks/conv_transformer.py | 93 ++++------------------------
 1 file changed, 13 insertions(+), 80 deletions(-)

diff --git a/text_recognizer/networks/conv_transformer.py b/text_recognizer/networks/conv_transformer.py
index ff98ec6..77e4984 100644
--- a/text_recognizer/networks/conv_transformer.py
+++ b/text_recognizer/networks/conv_transformer.py
@@ -5,6 +5,7 @@ from typing import Optional, Tuple, Type
 from loguru import logger as log
 from torch import nn, Tensor
 
+from text_recognizer.networks.base import BaseTransformer
 from text_recognizer.networks.transformer.axial_attention.encoder import AxialEncoder
 from text_recognizer.networks.transformer.embeddings.axial import (
     AxialPositionalEmbedding,
@@ -12,7 +13,7 @@ from text_recognizer.networks.transformer.embeddings.axial import (
 from text_recognizer.networks.transformer.layers import Decoder
 
 
-class ConvTransformer(nn.Module):
+class ConvTransformer(BaseTransformer):
     """Convolutional encoder and transformer decoder network."""
 
     def __init__(
@@ -27,15 +28,18 @@ class ConvTransformer(nn.Module):
         pixel_pos_embedding: AxialPositionalEmbedding,
         token_pos_embedding: Optional[Type[nn.Module]] = None,
     ) -> None:
-        super().__init__()
-        self.input_dims = input_dims
-        self.hidden_dim = hidden_dim
-        self.num_classes = num_classes
-        self.pad_index = pad_index
-        self.encoder = encoder
-        self.decoder = decoder
-        self.axial_encoder = axial_encoder
+        super().__init__(
+            input_dims,
+            hidden_dim,
+            num_classes,
+            pad_index,
+            encoder,
+            decoder,
+            token_pos_embedding,
+        )
+
         self.pixel_pos_embedding = pixel_pos_embedding
+        self.axial_encoder = axial_encoder
 
         # Latent projector for down sampling number of filters and 2d
         # positional encoding.
@@ -45,25 +49,6 @@ class ConvTransformer(nn.Module):
             kernel_size=1,
         )
 
-        # Token embedding.
-        self.token_embedding = nn.Embedding(
-            num_embeddings=self.num_classes, embedding_dim=self.hidden_dim
-        )
-
-        # Positional encoding for decoder tokens.
-        if not self.decoder.has_pos_emb:
-            self.token_pos_embedding = token_pos_embedding
-        else:
-            self.token_pos_embedding = None
-            log.debug("Decoder already have a positional embedding.")
-
-        self.norm = nn.LayerNorm(self.hidden_dim)
-
-        # Output layer
-        self.to_logits = nn.Linear(
-            in_features=self.hidden_dim, out_features=self.num_classes
-        )
-
         # Initalize weights for encoder.
         self.init_weights()
 
@@ -100,55 +85,3 @@ class ConvTransformer(nn.Module):
         # Permute tensor from [B, E, Ho * Wo] to [B, Sx, E]
         z = z.permute(0, 2, 1)
         return z
-
-    def decode(self, src: Tensor, trg: Tensor) -> Tensor:
-        """Decodes latent images embedding into word pieces.
-
-        Args:
-            src (Tensor): Latent images embedding.
-            trg (Tensor): Word embeddings.
-
-        Shapes:
-            - z: :math: `(B, Sx, E)`
-            - context: :math: `(B, Sy)`
-            - out: :math: `(B, Sy, T)`
-
-            where Sy is the length of the output and T is the number of tokens.
-
-        Returns:
-            Tensor: Sequence of word piece embeddings.
-        """
-        trg = trg.long()
-        trg_mask = trg != self.pad_index
-        trg = self.token_embedding(trg) * math.sqrt(self.hidden_dim)
-        trg = (
-            self.token_pos_embedding(trg)
-            if self.token_pos_embedding is not None
-            else trg
-        )
-        out = self.decoder(x=trg, context=src, input_mask=trg_mask)
-        out = self.norm(out)
-        logits = self.to_logits(out)  # [B, Sy, T]
-        logits = logits.permute(0, 2, 1)  # [B, T, Sy]
-        return logits
-
-    def forward(self, x: Tensor, context: Tensor) -> Tensor:
-        """Encodes images into word piece logtis.
-
-        Args:
-            x (Tensor): Input image(s).
-            context (Tensor): Target word embeddings.
-
-        Shapes:
-            - x: :math: `(B, C, H, W)`
-            - context: :math: `(B, Sy, T)`
-
-            where B is the batch size, C is the number of input channels, H is
-            the image height and W is the image width.
-
-        Returns:
-            Tensor: Sequence of logits.
-        """
-        z = self.encode(x)
-        logits = self.decode(z, context)
-        return logits
-- 
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