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Diffstat (limited to 'text_recognizer/networks/transformer/embeddings/axial.py')
| -rw-r--r-- | text_recognizer/networks/transformer/embeddings/axial.py | 104 | 
1 files changed, 0 insertions, 104 deletions
diff --git a/text_recognizer/networks/transformer/embeddings/axial.py b/text_recognizer/networks/transformer/embeddings/axial.py deleted file mode 100644 index 9b872a9..0000000 --- a/text_recognizer/networks/transformer/embeddings/axial.py +++ /dev/null @@ -1,104 +0,0 @@ -"""Axial attention for multi-dimensional data. - -Stolen from: -    https://github.com/lucidrains/axial-attention/blob/ -    eff2c10c2e76c735a70a6b995b571213adffbbb7/axial_attention/axial_attention.py#L100 -""" -from functools import reduce -from operator import mul -from typing import Optional, Sequence - -import torch -from torch import Tensor, nn - - -class AxialPositionalEmbedding(nn.Module): -    def __init__( -        self, -        dim: int, -        axial_shape: Sequence[int], -        axial_dims: Optional[Sequence[int]] = None, -    ) -> None: -        super().__init__() - -        self.dim = dim -        self.shape = axial_shape -        self.max_seq_len = reduce(mul, axial_shape, 1) - -        self.summed = axial_dims is None -        axial_dims = ((dim,) * len(axial_shape)) if self.summed else axial_dims - -        assert len(self.shape) == len( -            axial_dims -        ), "number of axial dimensions must equal the number of dimensions in the shape" -        assert ( -            self.summed or not self.summed and sum(axial_dims) == dim -        ), f"axial dimensions must sum up to the target dimension {dim}" - -        self.weights = ParameterList(self, "weights", len(axial_shape)) - -        for ind, (shape, axial_dim) in enumerate(zip(self.shape, axial_dims)): -            ax_shape = [1] * len(self.shape) -            ax_shape[ind] = shape -            ax_shape = (1, *ax_shape, axial_dim) -            ax_emb = nn.Parameter(torch.zeros(ax_shape).normal_(0, 1)) -            self.weights.append(ax_emb) - -    def forward(self, x: Tensor) -> Tensor: -        """Returns axial positional embedding.""" -        b, t, _ = x.shape -        assert ( -            t <= self.max_seq_len -        ), f"Sequence length ({t}) must be less than the maximum sequence length allowed ({self.max_seq_len})" -        embs = [] - -        for ax_emb in self.weights.to_list(): -            axial_dim = ax_emb.shape[-1] -            expand_shape = (b, *self.shape, axial_dim) -            emb = ax_emb.expand(expand_shape).reshape(b, self.max_seq_len, axial_dim) -            embs.append(emb) - -        pos_emb = sum(embs) if self.summed else torch.cat(embs, dim=-1) -        return pos_emb[:, :t].to(x) - - -# a mock parameter list object until below issue is resolved -# https://github.com/pytorch/pytorch/issues/36035 -class ParameterList(object): -    def __init__(self, kls, prefix, length): -        self.ind = 0 -        self.kls = kls -        self.prefix = prefix -        self.length = length - -    def _keyname(self, prefix, ind): -        return f"{prefix}_{ind}" - -    def append(self, x): -        setattr(self.kls, self._keyname(self.prefix, self.ind), x) -        self.ind += 1 - -    def to_list(self): -        return [ -            getattr(self.kls, self._keyname(self.prefix, i)) for i in range(self.length) -        ] - - -class AxialPositionalEmbeddingImage(nn.Module): -    def __init__( -        self, -        dim: int, -        axial_shape: Sequence[int], -        axial_dims: Optional[Sequence[int]] = None, -    ) -> None: -        super().__init__() -        axial_dims = (dim // 2, dim // 2) if axial_dims is None else axial_dims -        assert len(axial_shape) == 2, "Axial shape must have 2 dimensions for images" -        self.dim = dim -        self.pos_emb = AxialPositionalEmbedding(dim, axial_shape, axial_dims) - -    def forward(self, img): -        b, c, h, w = img.shape -        img = img.permute(0, 2, 3, 1).reshape(b, h * w, c) -        pos_emb = self.pos_emb(img) -        return pos_emb.reshape(b, h, w, self.dim).permute(0, 3, 1, 2)  |