更新 detacttracking
This commit is contained in:
568
detecttracking/ultralytics/models/sam/modules/encoders.py
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568
detecttracking/ultralytics/models/sam/modules/encoders.py
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# Ultralytics YOLO 🚀, AGPL-3.0 license
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from typing import Any, Optional, Tuple, Type
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import numpy as np
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import torch
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import torch.nn as nn
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import torch.nn.functional as F
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from ultralytics.nn.modules import LayerNorm2d, MLPBlock
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# This class and its supporting functions below lightly adapted from the ViTDet backbone available at: https://github.com/facebookresearch/detectron2/blob/main/detectron2/modeling/backbone/vit.py # noqa
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class ImageEncoderViT(nn.Module):
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def __init__(
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self,
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img_size: int = 1024,
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patch_size: int = 16,
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in_chans: int = 3,
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embed_dim: int = 768,
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depth: int = 12,
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num_heads: int = 12,
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mlp_ratio: float = 4.0,
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out_chans: int = 256,
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qkv_bias: bool = True,
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norm_layer: Type[nn.Module] = nn.LayerNorm,
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act_layer: Type[nn.Module] = nn.GELU,
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use_abs_pos: bool = True,
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use_rel_pos: bool = False,
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rel_pos_zero_init: bool = True,
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window_size: int = 0,
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global_attn_indexes: Tuple[int, ...] = (),
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) -> None:
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"""
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Args:
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img_size (int): Input image size.
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patch_size (int): Patch size.
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in_chans (int): Number of input image channels.
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embed_dim (int): Patch embedding dimension.
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depth (int): Depth of ViT.
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num_heads (int): Number of attention heads in each ViT block.
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mlp_ratio (float): Ratio of mlp hidden dim to embedding dim.
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qkv_bias (bool): If True, add a learnable bias to query, key, value.
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norm_layer (nn.Module): Normalization layer.
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act_layer (nn.Module): Activation layer.
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use_abs_pos (bool): If True, use absolute positional embeddings.
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use_rel_pos (bool): If True, add relative positional embeddings to the attention map.
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rel_pos_zero_init (bool): If True, zero initialize relative positional parameters.
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window_size (int): Window size for window attention blocks.
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global_attn_indexes (list): Indexes for blocks using global attention.
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"""
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super().__init__()
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self.img_size = img_size
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self.patch_embed = PatchEmbed(
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kernel_size=(patch_size, patch_size),
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stride=(patch_size, patch_size),
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in_chans=in_chans,
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embed_dim=embed_dim,
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)
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self.pos_embed: Optional[nn.Parameter] = None
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if use_abs_pos:
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# Initialize absolute positional embedding with pretrain image size.
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self.pos_embed = nn.Parameter(torch.zeros(1, img_size // patch_size, img_size // patch_size, embed_dim))
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self.blocks = nn.ModuleList()
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for i in range(depth):
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block = Block(
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dim=embed_dim,
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num_heads=num_heads,
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mlp_ratio=mlp_ratio,
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qkv_bias=qkv_bias,
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norm_layer=norm_layer,
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act_layer=act_layer,
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use_rel_pos=use_rel_pos,
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rel_pos_zero_init=rel_pos_zero_init,
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window_size=window_size if i not in global_attn_indexes else 0,
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input_size=(img_size // patch_size, img_size // patch_size),
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)
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self.blocks.append(block)
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self.neck = nn.Sequential(
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nn.Conv2d(
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embed_dim,
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out_chans,
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kernel_size=1,
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bias=False,
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),
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LayerNorm2d(out_chans),
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nn.Conv2d(
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out_chans,
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out_chans,
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kernel_size=3,
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padding=1,
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bias=False,
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),
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LayerNorm2d(out_chans),
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)
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def forward(self, x: torch.Tensor) -> torch.Tensor:
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x = self.patch_embed(x)
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if self.pos_embed is not None:
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x = x + self.pos_embed
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for blk in self.blocks:
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x = blk(x)
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return self.neck(x.permute(0, 3, 1, 2))
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class PromptEncoder(nn.Module):
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def __init__(
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self,
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embed_dim: int,
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image_embedding_size: Tuple[int, int],
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input_image_size: Tuple[int, int],
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mask_in_chans: int,
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activation: Type[nn.Module] = nn.GELU,
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) -> None:
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"""
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Encodes prompts for input to SAM's mask decoder.
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Args:
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embed_dim (int): The prompts' embedding dimension
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image_embedding_size (tuple(int, int)): The spatial size of the
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image embedding, as (H, W).
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input_image_size (int): The padded size of the image as input
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to the image encoder, as (H, W).
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mask_in_chans (int): The number of hidden channels used for
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encoding input masks.
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activation (nn.Module): The activation to use when encoding
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input masks.
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"""
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super().__init__()
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self.embed_dim = embed_dim
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self.input_image_size = input_image_size
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self.image_embedding_size = image_embedding_size
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self.pe_layer = PositionEmbeddingRandom(embed_dim // 2)
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self.num_point_embeddings: int = 4 # pos/neg point + 2 box corners
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point_embeddings = [nn.Embedding(1, embed_dim) for _ in range(self.num_point_embeddings)]
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self.point_embeddings = nn.ModuleList(point_embeddings)
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self.not_a_point_embed = nn.Embedding(1, embed_dim)
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self.mask_input_size = (4 * image_embedding_size[0], 4 * image_embedding_size[1])
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self.mask_downscaling = nn.Sequential(
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nn.Conv2d(1, mask_in_chans // 4, kernel_size=2, stride=2),
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LayerNorm2d(mask_in_chans // 4),
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activation(),
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nn.Conv2d(mask_in_chans // 4, mask_in_chans, kernel_size=2, stride=2),
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LayerNorm2d(mask_in_chans),
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activation(),
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nn.Conv2d(mask_in_chans, embed_dim, kernel_size=1),
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)
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self.no_mask_embed = nn.Embedding(1, embed_dim)
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def get_dense_pe(self) -> torch.Tensor:
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"""
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Returns the positional encoding used to encode point prompts,
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applied to a dense set of points the shape of the image encoding.
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Returns:
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torch.Tensor: Positional encoding with shape 1x(embed_dim)x(embedding_h)x(embedding_w)
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"""
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return self.pe_layer(self.image_embedding_size).unsqueeze(0)
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def _embed_points(
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self,
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points: torch.Tensor,
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labels: torch.Tensor,
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pad: bool,
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) -> torch.Tensor:
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"""Embeds point prompts."""
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points = points + 0.5 # Shift to center of pixel
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if pad:
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padding_point = torch.zeros((points.shape[0], 1, 2), device=points.device)
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padding_label = -torch.ones((labels.shape[0], 1), device=labels.device)
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points = torch.cat([points, padding_point], dim=1)
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labels = torch.cat([labels, padding_label], dim=1)
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point_embedding = self.pe_layer.forward_with_coords(points, self.input_image_size)
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point_embedding[labels == -1] = 0.0
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point_embedding[labels == -1] += self.not_a_point_embed.weight
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point_embedding[labels == 0] += self.point_embeddings[0].weight
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point_embedding[labels == 1] += self.point_embeddings[1].weight
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return point_embedding
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def _embed_boxes(self, boxes: torch.Tensor) -> torch.Tensor:
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"""Embeds box prompts."""
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boxes = boxes + 0.5 # Shift to center of pixel
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coords = boxes.reshape(-1, 2, 2)
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corner_embedding = self.pe_layer.forward_with_coords(coords, self.input_image_size)
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corner_embedding[:, 0, :] += self.point_embeddings[2].weight
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corner_embedding[:, 1, :] += self.point_embeddings[3].weight
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return corner_embedding
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def _embed_masks(self, masks: torch.Tensor) -> torch.Tensor:
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"""Embeds mask inputs."""
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return self.mask_downscaling(masks)
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def _get_batch_size(
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self,
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points: Optional[Tuple[torch.Tensor, torch.Tensor]],
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boxes: Optional[torch.Tensor],
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masks: Optional[torch.Tensor],
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) -> int:
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"""
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Gets the batch size of the output given the batch size of the input prompts.
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"""
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if points is not None:
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return points[0].shape[0]
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elif boxes is not None:
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return boxes.shape[0]
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elif masks is not None:
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return masks.shape[0]
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else:
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return 1
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def _get_device(self) -> torch.device:
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return self.point_embeddings[0].weight.device
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def forward(
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self,
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points: Optional[Tuple[torch.Tensor, torch.Tensor]],
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boxes: Optional[torch.Tensor],
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masks: Optional[torch.Tensor],
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) -> Tuple[torch.Tensor, torch.Tensor]:
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"""
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Embeds different types of prompts, returning both sparse and dense embeddings.
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Args:
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points (tuple(torch.Tensor, torch.Tensor), None): point coordinates and labels to embed.
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boxes (torch.Tensor, None): boxes to embed
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masks (torch.Tensor, None): masks to embed
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Returns:
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torch.Tensor: sparse embeddings for the points and boxes, with shape BxNx(embed_dim), where N is determined
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by the number of input points and boxes.
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torch.Tensor: dense embeddings for the masks, in the shape Bx(embed_dim)x(embed_H)x(embed_W)
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"""
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bs = self._get_batch_size(points, boxes, masks)
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sparse_embeddings = torch.empty((bs, 0, self.embed_dim), device=self._get_device())
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if points is not None:
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coords, labels = points
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point_embeddings = self._embed_points(coords, labels, pad=(boxes is None))
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sparse_embeddings = torch.cat([sparse_embeddings, point_embeddings], dim=1)
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if boxes is not None:
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box_embeddings = self._embed_boxes(boxes)
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sparse_embeddings = torch.cat([sparse_embeddings, box_embeddings], dim=1)
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if masks is not None:
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dense_embeddings = self._embed_masks(masks)
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else:
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dense_embeddings = self.no_mask_embed.weight.reshape(1, -1, 1,
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1).expand(bs, -1, self.image_embedding_size[0],
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self.image_embedding_size[1])
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return sparse_embeddings, dense_embeddings
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class PositionEmbeddingRandom(nn.Module):
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"""
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Positional encoding using random spatial frequencies.
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"""
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def __init__(self, num_pos_feats: int = 64, scale: Optional[float] = None) -> None:
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super().__init__()
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if scale is None or scale <= 0.0:
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scale = 1.0
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self.register_buffer('positional_encoding_gaussian_matrix', scale * torch.randn((2, num_pos_feats)))
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# Set non-deterministic for forward() error 'cumsum_cuda_kernel does not have a deterministic implementation'
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torch.use_deterministic_algorithms(False)
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torch.backends.cudnn.deterministic = False
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def _pe_encoding(self, coords: torch.Tensor) -> torch.Tensor:
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"""Positionally encode points that are normalized to [0,1]."""
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# assuming coords are in [0, 1]^2 square and have d_1 x ... x d_n x 2 shape
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coords = 2 * coords - 1
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coords = coords @ self.positional_encoding_gaussian_matrix
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coords = 2 * np.pi * coords
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# outputs d_1 x ... x d_n x C shape
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return torch.cat([torch.sin(coords), torch.cos(coords)], dim=-1)
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def forward(self, size: Tuple[int, int]) -> torch.Tensor:
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"""Generate positional encoding for a grid of the specified size."""
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h, w = size
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device: Any = self.positional_encoding_gaussian_matrix.device
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grid = torch.ones((h, w), device=device, dtype=torch.float32)
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y_embed = grid.cumsum(dim=0) - 0.5
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x_embed = grid.cumsum(dim=1) - 0.5
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y_embed = y_embed / h
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x_embed = x_embed / w
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pe = self._pe_encoding(torch.stack([x_embed, y_embed], dim=-1))
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return pe.permute(2, 0, 1) # C x H x W
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def forward_with_coords(self, coords_input: torch.Tensor, image_size: Tuple[int, int]) -> torch.Tensor:
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"""Positionally encode points that are not normalized to [0,1]."""
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coords = coords_input.clone()
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coords[:, :, 0] = coords[:, :, 0] / image_size[1]
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coords[:, :, 1] = coords[:, :, 1] / image_size[0]
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return self._pe_encoding(coords.to(torch.float)) # B x N x C
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class Block(nn.Module):
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"""Transformer blocks with support of window attention and residual propagation blocks"""
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def __init__(
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self,
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dim: int,
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num_heads: int,
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mlp_ratio: float = 4.0,
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qkv_bias: bool = True,
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norm_layer: Type[nn.Module] = nn.LayerNorm,
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act_layer: Type[nn.Module] = nn.GELU,
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use_rel_pos: bool = False,
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rel_pos_zero_init: bool = True,
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window_size: int = 0,
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input_size: Optional[Tuple[int, int]] = None,
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) -> None:
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"""
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Args:
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dim (int): Number of input channels.
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num_heads (int): Number of attention heads in each ViT block.
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mlp_ratio (float): Ratio of mlp hidden dim to embedding dim.
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qkv_bias (bool): If True, add a learnable bias to query, key, value.
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norm_layer (nn.Module): Normalization layer.
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act_layer (nn.Module): Activation layer.
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use_rel_pos (bool): If True, add relative positional embeddings to the attention map.
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rel_pos_zero_init (bool): If True, zero initialize relative positional parameters.
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window_size (int): Window size for window attention blocks. If it equals 0, then
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use global attention.
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input_size (tuple(int, int), None): Input resolution for calculating the relative
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positional parameter size.
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"""
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super().__init__()
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self.norm1 = norm_layer(dim)
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self.attn = Attention(
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dim,
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num_heads=num_heads,
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qkv_bias=qkv_bias,
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use_rel_pos=use_rel_pos,
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rel_pos_zero_init=rel_pos_zero_init,
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input_size=input_size if window_size == 0 else (window_size, window_size),
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)
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self.norm2 = norm_layer(dim)
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self.mlp = MLPBlock(embedding_dim=dim, mlp_dim=int(dim * mlp_ratio), act=act_layer)
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self.window_size = window_size
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def forward(self, x: torch.Tensor) -> torch.Tensor:
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shortcut = x
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x = self.norm1(x)
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# Window partition
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if self.window_size > 0:
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H, W = x.shape[1], x.shape[2]
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x, pad_hw = window_partition(x, self.window_size)
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x = self.attn(x)
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# Reverse window partition
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if self.window_size > 0:
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x = window_unpartition(x, self.window_size, pad_hw, (H, W))
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x = shortcut + x
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return x + self.mlp(self.norm2(x))
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class Attention(nn.Module):
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"""Multi-head Attention block with relative position embeddings."""
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def __init__(
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self,
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dim: int,
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num_heads: int = 8,
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qkv_bias: bool = True,
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use_rel_pos: bool = False,
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rel_pos_zero_init: bool = True,
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input_size: Optional[Tuple[int, int]] = None,
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) -> None:
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"""
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Args:
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dim (int): Number of input channels.
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num_heads (int): Number of attention heads.
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qkv_bias (bool): If True, add a learnable bias to query, key, value.
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rel_pos_zero_init (bool): If True, zero initialize relative positional parameters.
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input_size (tuple(int, int), None): Input resolution for calculating the relative
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positional parameter size.
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"""
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super().__init__()
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self.num_heads = num_heads
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head_dim = dim // num_heads
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self.scale = head_dim ** -0.5
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self.qkv = nn.Linear(dim, dim * 3, bias=qkv_bias)
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self.proj = nn.Linear(dim, dim)
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self.use_rel_pos = use_rel_pos
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if self.use_rel_pos:
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assert (input_size is not None), 'Input size must be provided if using relative positional encoding.'
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# initialize relative positional embeddings
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self.rel_pos_h = nn.Parameter(torch.zeros(2 * input_size[0] - 1, head_dim))
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self.rel_pos_w = nn.Parameter(torch.zeros(2 * input_size[1] - 1, head_dim))
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def forward(self, x: torch.Tensor) -> torch.Tensor:
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B, H, W, _ = x.shape
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# qkv with shape (3, B, nHead, H * W, C)
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qkv = self.qkv(x).reshape(B, H * W, 3, self.num_heads, -1).permute(2, 0, 3, 1, 4)
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# q, k, v with shape (B * nHead, H * W, C)
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q, k, v = qkv.reshape(3, B * self.num_heads, H * W, -1).unbind(0)
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attn = (q * self.scale) @ k.transpose(-2, -1)
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if self.use_rel_pos:
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attn = add_decomposed_rel_pos(attn, q, self.rel_pos_h, self.rel_pos_w, (H, W), (H, W))
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attn = attn.softmax(dim=-1)
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x = (attn @ v).view(B, self.num_heads, H, W, -1).permute(0, 2, 3, 1, 4).reshape(B, H, W, -1)
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return self.proj(x)
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|
||||
def window_partition(x: torch.Tensor, window_size: int) -> Tuple[torch.Tensor, Tuple[int, int]]:
|
||||
"""
|
||||
Partition into non-overlapping windows with padding if needed.
|
||||
Args:
|
||||
x (tensor): input tokens with [B, H, W, C].
|
||||
window_size (int): window size.
|
||||
|
||||
Returns:
|
||||
windows: windows after partition with [B * num_windows, window_size, window_size, C].
|
||||
(Hp, Wp): padded height and width before partition
|
||||
"""
|
||||
B, H, W, C = x.shape
|
||||
|
||||
pad_h = (window_size - H % window_size) % window_size
|
||||
pad_w = (window_size - W % window_size) % window_size
|
||||
if pad_h > 0 or pad_w > 0:
|
||||
x = F.pad(x, (0, 0, 0, pad_w, 0, pad_h))
|
||||
Hp, Wp = H + pad_h, W + pad_w
|
||||
|
||||
x = x.view(B, Hp // window_size, window_size, Wp // window_size, window_size, C)
|
||||
windows = x.permute(0, 1, 3, 2, 4, 5).contiguous().view(-1, window_size, window_size, C)
|
||||
return windows, (Hp, Wp)
|
||||
|
||||
|
||||
def window_unpartition(windows: torch.Tensor, window_size: int, pad_hw: Tuple[int, int],
|
||||
hw: Tuple[int, int]) -> torch.Tensor:
|
||||
"""
|
||||
Window unpartition into original sequences and removing padding.
|
||||
Args:
|
||||
windows (tensor): input tokens with [B * num_windows, window_size, window_size, C].
|
||||
window_size (int): window size.
|
||||
pad_hw (Tuple): padded height and width (Hp, Wp).
|
||||
hw (Tuple): original height and width (H, W) before padding.
|
||||
|
||||
Returns:
|
||||
x: unpartitioned sequences with [B, H, W, C].
|
||||
"""
|
||||
Hp, Wp = pad_hw
|
||||
H, W = hw
|
||||
B = windows.shape[0] // (Hp * Wp // window_size // window_size)
|
||||
x = windows.view(B, Hp // window_size, Wp // window_size, window_size, window_size, -1)
|
||||
x = x.permute(0, 1, 3, 2, 4, 5).contiguous().view(B, Hp, Wp, -1)
|
||||
|
||||
if Hp > H or Wp > W:
|
||||
x = x[:, :H, :W, :].contiguous()
|
||||
return x
|
||||
|
||||
|
||||
def get_rel_pos(q_size: int, k_size: int, rel_pos: torch.Tensor) -> torch.Tensor:
|
||||
"""
|
||||
Get relative positional embeddings according to the relative positions of
|
||||
query and key sizes.
|
||||
Args:
|
||||
q_size (int): size of query q.
|
||||
k_size (int): size of key k.
|
||||
rel_pos (Tensor): relative position embeddings (L, C).
|
||||
|
||||
Returns:
|
||||
Extracted positional embeddings according to relative positions.
|
||||
"""
|
||||
max_rel_dist = int(2 * max(q_size, k_size) - 1)
|
||||
# Interpolate rel pos if needed.
|
||||
if rel_pos.shape[0] != max_rel_dist:
|
||||
# Interpolate rel pos.
|
||||
rel_pos_resized = F.interpolate(
|
||||
rel_pos.reshape(1, rel_pos.shape[0], -1).permute(0, 2, 1),
|
||||
size=max_rel_dist,
|
||||
mode='linear',
|
||||
)
|
||||
rel_pos_resized = rel_pos_resized.reshape(-1, max_rel_dist).permute(1, 0)
|
||||
else:
|
||||
rel_pos_resized = rel_pos
|
||||
|
||||
# Scale the coords with short length if shapes for q and k are different.
|
||||
q_coords = torch.arange(q_size)[:, None] * max(k_size / q_size, 1.0)
|
||||
k_coords = torch.arange(k_size)[None, :] * max(q_size / k_size, 1.0)
|
||||
relative_coords = (q_coords - k_coords) + (k_size - 1) * max(q_size / k_size, 1.0)
|
||||
|
||||
return rel_pos_resized[relative_coords.long()]
|
||||
|
||||
|
||||
def add_decomposed_rel_pos(
|
||||
attn: torch.Tensor,
|
||||
q: torch.Tensor,
|
||||
rel_pos_h: torch.Tensor,
|
||||
rel_pos_w: torch.Tensor,
|
||||
q_size: Tuple[int, int],
|
||||
k_size: Tuple[int, int],
|
||||
) -> torch.Tensor:
|
||||
"""
|
||||
Calculate decomposed Relative Positional Embeddings from :paper:`mvitv2`.
|
||||
https://github.com/facebookresearch/mvit/blob/19786631e330df9f3622e5402b4a419a263a2c80/mvit/models/attention.py # noqa B950
|
||||
Args:
|
||||
attn (Tensor): attention map.
|
||||
q (Tensor): query q in the attention layer with shape (B, q_h * q_w, C).
|
||||
rel_pos_h (Tensor): relative position embeddings (Lh, C) for height axis.
|
||||
rel_pos_w (Tensor): relative position embeddings (Lw, C) for width axis.
|
||||
q_size (Tuple): spatial sequence size of query q with (q_h, q_w).
|
||||
k_size (Tuple): spatial sequence size of key k with (k_h, k_w).
|
||||
|
||||
Returns:
|
||||
attn (Tensor): attention map with added relative positional embeddings.
|
||||
"""
|
||||
q_h, q_w = q_size
|
||||
k_h, k_w = k_size
|
||||
Rh = get_rel_pos(q_h, k_h, rel_pos_h)
|
||||
Rw = get_rel_pos(q_w, k_w, rel_pos_w)
|
||||
|
||||
B, _, dim = q.shape
|
||||
r_q = q.reshape(B, q_h, q_w, dim)
|
||||
rel_h = torch.einsum('bhwc,hkc->bhwk', r_q, Rh)
|
||||
rel_w = torch.einsum('bhwc,wkc->bhwk', r_q, Rw)
|
||||
|
||||
attn = (attn.view(B, q_h, q_w, k_h, k_w) + rel_h[:, :, :, :, None] + rel_w[:, :, :, None, :]).view(
|
||||
B, q_h * q_w, k_h * k_w)
|
||||
|
||||
return attn
|
||||
|
||||
|
||||
class PatchEmbed(nn.Module):
|
||||
"""
|
||||
Image to Patch Embedding.
|
||||
"""
|
||||
|
||||
def __init__(
|
||||
self,
|
||||
kernel_size: Tuple[int, int] = (16, 16),
|
||||
stride: Tuple[int, int] = (16, 16),
|
||||
padding: Tuple[int, int] = (0, 0),
|
||||
in_chans: int = 3,
|
||||
embed_dim: int = 768,
|
||||
) -> None:
|
||||
"""
|
||||
Args:
|
||||
kernel_size (Tuple): kernel size of the projection layer.
|
||||
stride (Tuple): stride of the projection layer.
|
||||
padding (Tuple): padding size of the projection layer.
|
||||
in_chans (int): Number of input image channels.
|
||||
embed_dim (int): Patch embedding dimension.
|
||||
"""
|
||||
super().__init__()
|
||||
|
||||
self.proj = nn.Conv2d(in_chans, embed_dim, kernel_size=kernel_size, stride=stride, padding=padding)
|
||||
|
||||
def forward(self, x: torch.Tensor) -> torch.Tensor:
|
||||
return self.proj(x).permute(0, 2, 3, 1) # B C H W -> B H W C
|
Reference in New Issue
Block a user