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import torch.nn as nn |
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import torch |
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import torch.nn.functional as F |
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import copy |
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from contextlib import nullcontext |
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import math |
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from typing import Optional, Tuple |
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from einops import rearrange |
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from easydict import EasyDict as adict |
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from typing import Optional, Tuple, Type |
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from functools import partial |
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class MlpProjector(nn.Module): |
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def __init__(self, cfg): |
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super().__init__() |
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self.cfg = cfg |
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if cfg.projector_type == "identity": |
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modules = nn.Identity() |
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elif cfg.projector_type == "linear": |
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modules = nn.Linear(cfg.input_dim, cfg.n_embed) |
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elif cfg.projector_type == "mlp_gelu": |
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mlp_depth = cfg.get("depth", 1) |
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modules = [nn.Linear(cfg.input_dim, cfg.n_embed)] |
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for _ in range(1, mlp_depth): |
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modules.append(nn.GELU()) |
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modules.append(nn.Linear(cfg.n_embed, cfg.n_embed)) |
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modules = nn.Sequential(*modules) |
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elif cfg.projector_type == "normlayer_downsample_mlp_gelu": |
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mlp_depth = cfg.get("depth", 1) |
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mlp_ratio = cfg.get("mlp_ratio", 1) |
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modules = [ |
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nn.LayerNorm(cfg.input_dim * cfg.downsample_ratio * cfg.downsample_ratio), |
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nn.Linear(cfg.input_dim * cfg.downsample_ratio * cfg.downsample_ratio, cfg.n_embed * mlp_ratio) |
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] |
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for _ in range(1, mlp_depth - 1): |
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modules.append(nn.GELU()) |
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modules.append(nn.Linear(cfg.n_embed * mlp_ratio, cfg.n_embed * mlp_ratio)) |
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modules.append(nn.GELU()) |
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modules.append(nn.Linear(cfg.n_embed * mlp_ratio, cfg.n_embed)) |
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modules = nn.Sequential(*modules) |
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elif cfg.projector_type == "downsample_mlp_gelu": |
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mlp_depth = cfg.get("depth", 1) |
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mlp_ratio = cfg.get("mlp_ratio", 1) |
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modules = [nn.Linear(cfg.input_dim * cfg.downsample_ratio * cfg.downsample_ratio, cfg.n_embed * mlp_ratio)] |
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for _ in range(1, mlp_depth - 1): |
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modules.append(nn.GELU()) |
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modules.append(nn.Linear(cfg.n_embed * mlp_ratio, cfg.n_embed * mlp_ratio)) |
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modules.append(nn.GELU()) |
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modules.append(nn.Linear(cfg.n_embed * mlp_ratio, cfg.n_embed)) |
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modules = nn.Sequential(*modules) |
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elif cfg.projector_type == "low_high_hybrid_split_mlp_gelu": |
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mlp_depth = cfg.get("depth", 1) |
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self.high_up_proj = nn.Linear(cfg.input_dim, cfg.n_embed // 2) |
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self.low_up_proj = nn.Linear(cfg.input_dim, cfg.n_embed // 2) |
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modules = [] |
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for _ in range(1, mlp_depth): |
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modules.append(nn.GELU()) |
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modules.append(nn.Linear(cfg.n_embed, cfg.n_embed)) |
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modules = nn.Sequential(*modules) |
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elif cfg.projector_type == "hybrid_split_feature_mlp_gelu": |
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mlp_depth = cfg.get("depth", 1) |
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channel_div = cfg.get("channel_div", 0.5) |
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self.high_up_proj = nn.Linear(cfg.input_dim[0], int(cfg.n_embed * channel_div)) |
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self.low_up_proj = nn.Linear(cfg.input_dim[1], cfg.n_embed - int(cfg.n_embed * channel_div)) |
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modules = [] |
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for _ in range(1, mlp_depth): |
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modules.append(nn.GELU()) |
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modules.append(nn.Linear(cfg.n_embed, cfg.n_embed)) |
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modules = nn.Sequential(*modules) |
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elif cfg.projector_type == "low_high_split_mlp_gelu": |
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mlp_depth = cfg.get("depth", 1) |
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modules = [] |
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for _ in range(1, mlp_depth): |
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modules.append(nn.GELU()) |
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modules.append(nn.Linear(cfg.n_embed // 2, cfg.n_embed // 2)) |
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modules = nn.Sequential(*modules) |
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self.high_layers = nn.Sequential(*modules) |
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self.low_layers = copy.deepcopy(modules) |
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else: |
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raise ValueError(f"Unknown projector type: {cfg.projector_type}") |
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if cfg.get("token_pooling", False): |
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self.token_pooling_layer = nn.Linear(cfg.input_dim * 4, cfg.input_dim) |
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if cfg.get("conv_fusion_high_low_features", False): |
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self.fusion_layer = nn.Linear(cfg.input_dim, cfg.input_dim) |
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self.layers = modules |
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def forward(self, x): |
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if self.cfg.get("token_pooling", False): |
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batch_size, wxh, channels = x.shape |
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w = h = int(wxh**0.5) |
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x = x.view(batch_size, w, h, channels) |
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x = x.permute(0, 3, 1, 2) |
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patches = x.unfold(2, 2, 2).unfold(3, 2, 2) |
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batch_size, channels, h_patches, w_patches, _, _ = patches.size() |
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patches = patches.contiguous().view(batch_size, channels, h_patches * w_patches, -1) |
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patches = patches.permute(0, 2, 1, 3).contiguous() |
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patches = patches.view(batch_size, h_patches * w_patches, channels * 4) |
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x = self.token_pooling_layer(patches) |
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if self.cfg.get("conv_fusion_high_low_features", False): |
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x = self.fusion_layer(x[:, 0]) + x[:, 1] |
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if self.cfg.projector_type == 'low_high_hybrid_split_mlp_gelu': |
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high_x, low_x = x[0], x[1] |
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high_x = self.high_up_proj(high_x) |
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low_x = self.low_up_proj(low_x) |
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x = torch.concat([high_x, low_x], dim=-1) |
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if self.cfg.projector_type == 'hybrid_split_feature_mlp_gelu': |
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high_x = x[...,:self.cfg.input_dim[0]] |
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low_x = x[...,self.cfg.input_dim[0]:] |
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high_x = self.high_up_proj(high_x) |
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low_x = self.low_up_proj(low_x) |
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x = torch.concat([high_x, low_x], dim=-1) |
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if self.cfg.projector_type == 'low_high_split_mlp_gelu': |
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high_x, low_x = x[0], x[1] |
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high_x = self.high_layers(high_x) |
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low_x = self.low_layers(low_x) |
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x = torch.concat([high_x, low_x], dim=-1) |
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return x |
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if self.cfg.projector_type == 'downsample_mlp_gelu' or self.cfg.projector_type == 'normlayer_downsample_mlp_gelu': |
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bs, hw, input_dim = x.shape |
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h = w = int((hw) ** 0.5) |
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"""compute padding""" |
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if h % self.cfg.downsample_ratio: |
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pad = self.cfg.downsample_ratio - h % self.cfg.downsample_ratio |
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else: |
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pad = 0 |
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x = x.reshape(bs, h, w, input_dim) |
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if pad > 0: |
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x = F.pad(x, (0, 0, 0, pad, 0, pad), "constant", 0) |
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"""4 to 1 concat""" |
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x = x.permute(0, 3, 1, 2) |
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x = F.unfold(x, kernel_size=self.cfg.downsample_ratio, stride=self.cfg.downsample_ratio, padding=0) |
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x = x.permute(0, 2, 1) |
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return self.layers(x) |
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@staticmethod |
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def get_flops_per_sample(cfg): |
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if cfg.projector_type == "linear": |
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fwd = 2 * cfg.input_dim * cfg.n_embed |
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elif "mlp_gelu" in cfg.projector_type : |
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mlp_depth = cfg.get("depth", 1) |
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downsample_ratio = cfg.get("downsample_ratio", 1) |
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input_dim = sum(cfg.input_dim) if isinstance(cfg.input_dim, list) else cfg.input_dim |
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input_dim = input_dim * downsample_ratio * downsample_ratio |
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fwd = 2 * input_dim * cfg.n_embed + (mlp_depth - 1) * 2 * cfg.n_embed * cfg.n_embed |
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else: |
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fwd = 0 |
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return fwd * 3 |
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class LayerNormfp32(torch.nn.LayerNorm): |
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"""Subclass torch's LayerNorm to handle fp16.""" |
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def forward(self, x: torch.Tensor): |
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orig_type = x.dtype |
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ret = super().forward(x.type(torch.float32)) |
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return ret.type(orig_type) |
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def get_abs_pos(abs_pos, tgt_size): |
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dim = abs_pos.size(-1) |
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abs_pos_new = abs_pos.squeeze(0) |
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cls_token, old_pos_embed = abs_pos_new[:1], abs_pos_new[1:] |
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src_size = int(math.sqrt(abs_pos_new.shape[0] - 1)) |
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tgt_size = int(math.sqrt(tgt_size)) |
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dtype = abs_pos.dtype |
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if src_size != tgt_size: |
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old_pos_embed = old_pos_embed.view(1, src_size, src_size, dim).permute(0, 3, 1, |
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2).contiguous() |
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old_pos_embed = old_pos_embed.to(torch.float32) |
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new_pos_embed = F.interpolate( |
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old_pos_embed, |
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size=(tgt_size, tgt_size), |
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mode='bicubic', |
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antialias=True, |
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align_corners=False, |
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).to(dtype) |
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new_pos_embed = new_pos_embed.permute(0, 2, 3, 1) |
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new_pos_embed = new_pos_embed.view(tgt_size * tgt_size, dim) |
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vision_pos_embed = torch.cat([cls_token, new_pos_embed], dim=0) |
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vision_pos_embed = vision_pos_embed.view(1, tgt_size * tgt_size + 1, dim) |
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return vision_pos_embed |
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else: |
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return abs_pos |
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@torch.jit.script |
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def quick_gelu(x): |
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return x * torch.sigmoid(1.702 * x) |
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class CLIPVisionEmbeddings(nn.Module): |
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def __init__(self, hidden_size=1024, image_size=224, patch_size=14, num_channels=3): |
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super().__init__() |
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self.embed_dim = hidden_size |
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self.image_size = image_size |
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self.patch_size = patch_size |
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self.class_embedding = torch.nn.Parameter(torch.randn(self.embed_dim)) |
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self.patch_embedding = torch.nn.Conv2d( |
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in_channels=num_channels, |
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out_channels=self.embed_dim, |
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kernel_size=self.patch_size, |
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stride=self.patch_size, |
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bias=False, |
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) |
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self.num_patches = (self.image_size // self.patch_size) ** 2 |
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self.num_positions = self.num_patches + 1 |
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self.position_embedding = torch.nn.Embedding(self.num_positions, self.embed_dim) |
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self.register_buffer( |
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"position_ids", torch.arange(self.num_positions).expand((1, -1)) |
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) |
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def forward(self, pixel_values, patch_embeds): |
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batch_size = pixel_values.shape[0] |
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if patch_embeds is not None: |
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patch_embeds = patch_embeds |
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else: |
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patch_embeds = self.patch_embedding(pixel_values) |
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patch_embeds = patch_embeds.flatten(2).transpose(1, 2) |
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class_embeds = self.class_embedding.expand(batch_size, 1, -1) |
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embeddings = torch.cat([class_embeds, patch_embeds], dim=1) |
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embeddings = embeddings + get_abs_pos(self.position_embedding(self.position_ids), embeddings.size(1)) |
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return embeddings |
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class NoTPFeedForward(nn.Module): |
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def __init__( |
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self, |
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cfg, |
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dim: int, |
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hidden_dim: int, |
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): |
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super().__init__() |
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self.fc1 = torch.nn.Linear(dim, hidden_dim, bias=True) |
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self.fc2 = torch.nn.Linear(hidden_dim, dim, bias=True) |
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def forward(self, x): |
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output = self.fc2(quick_gelu(self.fc1(x))) |
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return output |
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class NoTPAttention(torch.nn.Module): |
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def __init__(self, cfg): |
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super().__init__() |
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self.num_heads = cfg.num_attention_heads |
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self.n_local_heads = cfg.num_attention_heads |
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self.head_dim = cfg.hidden_size // cfg.num_attention_heads |
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self.max_seq_len = cfg.seq_length |
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self.use_flash_attention = cfg.use_flash_attn |
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self.qkv_proj = torch.nn.Linear(cfg.hidden_size, cfg.hidden_size * 3, bias=True) |
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self.out_proj = torch.nn.Linear(cfg.hidden_size, cfg.hidden_size, bias=True) |
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self.attn_drop = cfg.attention_dropout |
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def forward( |
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self, |
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x: torch.Tensor, |
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): |
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bsz, seqlen, _ = x.shape |
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xqkv = self.qkv_proj(x) |
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xqkv = xqkv.view(bsz, seqlen, 3, self.num_heads, self.head_dim) |
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if self.use_flash_attention: |
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xq, xk, xv = torch.split(xqkv, 1, dim=2) |
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xq = xq.squeeze(2) |
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xk = xk.squeeze(2) |
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xv = xv.squeeze(2) |
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xq = xq.permute(0, 2, 1, 3) |
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xk = xk.permute(0, 2, 1, 3) |
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xv = xv.permute(0, 2, 1, 3) |
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output = torch.nn.functional.scaled_dot_product_attention(xq, xk, xv, attn_mask=None) |
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output = output.permute(0, 2, 1, 3).reshape(bsz, seqlen, -1) |
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else: |
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xq, xk, xv = torch.split(xqkv, 1, dim=2) |
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xq = xq.squeeze(2) |
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xk = xk.squeeze(2) |
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xv = xv.squeeze(2) |
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xq = xq.permute(0, 2, 1, 3) |
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xk = xk.permute(0, 2, 1, 3) |
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xv = xv.permute(0, 2, 1, 3) |
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output = torch.nn.functional.scaled_dot_product_attention(xq, xk, xv, attn_mask=None) |
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output = output.permute(0, 2, 1, 3).reshape(bsz, seqlen, -1) |
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output = self.out_proj(output) |
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return output |
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class NoTPTransformerBlock(nn.Module): |
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def __init__(self, cfg, layer_id: int, multiple_of=256): |
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super().__init__() |
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self.n_heads = cfg.num_attention_heads |
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self.dim = cfg.hidden_size |
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self.head_dim = cfg.hidden_size // cfg.num_attention_heads |
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self.self_attn = NoTPAttention(cfg) |
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self.mlp = NoTPFeedForward( |
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cfg, dim=cfg.hidden_size, hidden_dim=cfg.ffn_hidden_size |
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) |
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self.layer_id = layer_id |
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self.layer_norm1 = torch.nn.LayerNorm( |
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cfg.hidden_size, eps=cfg.layernorm_epsilon |
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) |
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self.layer_norm2 = torch.nn.LayerNorm( |
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cfg.hidden_size, eps=cfg.layernorm_epsilon |
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) |
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def forward(self, x: torch.Tensor): |
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residual = self.self_attn.forward(self.layer_norm1(x)) |
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h = x + residual |
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out = h + self.mlp.forward(self.layer_norm2(h)) |
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return out |
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class NoTPTransformer(nn.Module): |
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def __init__(self, cfg): |
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super().__init__() |
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self.cfg = cfg |
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self.num_layers = cfg.num_layers |
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self.layers = torch.nn.ModuleList() |
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for layer_id in range(self.num_layers): |
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self.layers.append( |
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NoTPTransformerBlock( |
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cfg, |
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layer_id + 1, |
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) |
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) |
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def forward( |
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self, |
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hidden_states, |
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): |
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for lid, layer in enumerate(self.layers): |
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hidden_states = layer(hidden_states) |
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return hidden_states |
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class VitModel(nn.Module): |
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def __init__( |
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self, |
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cfg, |
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freeze_embed=False, |
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freeze_pre_norm=False |
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) -> None: |
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super().__init__() |
|
|
|
|
|
self.embeddings = CLIPVisionEmbeddings(hidden_size=cfg.hidden_size, image_size=cfg.image_size, patch_size=cfg.patch_size) |
|
|
|
|
|
if freeze_embed: |
|
|
for name, param in self.embeddings.named_parameters(): |
|
|
param.requires_grad = False |
|
|
|
|
|
self.transformer = NoTPTransformer(cfg=cfg) |
|
|
|
|
|
if cfg.get("fp32norm", False): |
|
|
logger.info("Load fp32 layernorm for ViT.") |
|
|
self.pre_layrnorm = LayerNormfp32( |
|
|
cfg.hidden_size, |
|
|
eps=cfg.get("pre_layernorm_epsilon", 1e-5), |
|
|
) |
|
|
else: |
|
|
self.pre_layrnorm = torch.nn.LayerNorm( |
|
|
cfg.hidden_size, |
|
|
eps=cfg.get("pre_layernorm_epsilon", 1e-5), |
|
|
) |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
if freeze_pre_norm: |
|
|
for name, param in self.pre_layrnorm.named_parameters(): |
|
|
param.requires_grad = False |
|
|
|
|
|
for p in self.parameters(): |
|
|
p.micro_dp = True |
|
|
|
|
|
def set_input_tensor(self, input_tensor): |
|
|
if not isinstance(input_tensor, list): |
|
|
input_tensor = [input_tensor] |
|
|
self.transformer.set_input_tensor(input_tensor[0]) |
|
|
|
|
|
def __str__(self) -> str: |
|
|
return "open_clip" |
|
|
|
|
|
def forward( |
|
|
self, |
|
|
x, |
|
|
patch_embeds |
|
|
): |
|
|
x = self.embeddings(x, patch_embeds) |
|
|
hidden_states = self.pre_layrnorm(x) |
|
|
|
|
|
|
|
|
output = self.transformer(hidden_states) |
|
|
|
|
|
|
|
|
|
|
|
return output |
|
|
|
|
|
|
|
|
vit_model_cfg = adict( |
|
|
num_layers=24, |
|
|
hidden_size=1024, |
|
|
num_heads = 16, |
|
|
num_attention_heads=16, |
|
|
ffn_hidden_size=4096, |
|
|
seq_length=256, |
|
|
max_position_embeddings=256, |
|
|
use_flash_attn=False, |
|
|
understand_projector_stride=2, |
|
|
hidden_dropout = 0.0, |
|
|
attention_dropout = 0.0, |
|
|
no_persist_layer_norm = False, |
|
|
layernorm_epsilon = 1e-5, |
|
|
pre_layernorm_epsilon = 1e-5, |
|
|
image_size = 224, |
|
|
patch_size = 14, |
|
|
recompute_list = [] |
|
|
) |
|
|
|
|
|
def build_clip_l(): |
|
|
return VitModel( |
|
|
cfg=vit_model_cfg, |
|
|
freeze_embed=False, |
|
|
freeze_pre_norm=False, |
|
|
) |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
def get_abs_pos_sam(abs_pos, tgt_size): |
|
|
|
|
|
dtype = abs_pos.dtype |
|
|
|
|
|
src_size = abs_pos.size(1) |
|
|
|
|
|
if src_size != tgt_size: |
|
|
old_pos_embed = abs_pos.permute(0, 3, 1, 2) |
|
|
old_pos_embed = old_pos_embed.to(torch.float32) |
|
|
new_pos_embed = F.interpolate( |
|
|
old_pos_embed, |
|
|
size=(tgt_size, tgt_size), |
|
|
mode='bicubic', |
|
|
antialias=True, |
|
|
align_corners=False, |
|
|
).to(dtype) |
|
|
new_pos_embed = new_pos_embed.permute(0, 2, 3, 1) |
|
|
return new_pos_embed |
|
|
else: |
|
|
return abs_pos |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
class MLPBlock(nn.Module): |
|
|
def __init__( |
|
|
self, |
|
|
embedding_dim: int, |
|
|
mlp_dim: int, |
|
|
act: Type[nn.Module] = nn.GELU, |
|
|
) -> None: |
|
|
super().__init__() |
|
|
self.lin1 = nn.Linear(embedding_dim, mlp_dim) |
|
|
self.lin2 = nn.Linear(mlp_dim, embedding_dim) |
|
|
self.act = act() |
|
|
|
|
|
def forward(self, x: torch.Tensor) -> torch.Tensor: |
|
|
return self.lin2(self.act(self.lin1(x))) |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
class LayerNorm2d(nn.Module): |
|
|
def __init__(self, num_channels: int, eps: float = 1e-6) -> None: |
|
|
super().__init__() |
|
|
self.weight = nn.Parameter(torch.ones(num_channels)) |
|
|
self.bias = nn.Parameter(torch.zeros(num_channels)) |
|
|
self.eps = eps |
|
|
|
|
|
def forward(self, x: torch.Tensor) -> torch.Tensor: |
|
|
u = x.mean(1, keepdim=True) |
|
|
s = (x - u).pow(2).mean(1, keepdim=True) |
|
|
x = (x - u) / torch.sqrt(s + self.eps) |
|
|
x = self.weight[:, None, None] * x + self.bias[:, None, None] |
|
|
return x |
|
|
|
|
|
|
|
|
|
|
|
class ImageEncoderViT(nn.Module): |
|
|
def __init__( |
|
|
self, |
|
|
img_size: int = 1024, |
|
|
patch_size: int = 16, |
|
|
in_chans: int = 3, |
|
|
embed_dim: int = 768, |
|
|
depth: int = 12, |
|
|
num_heads: int = 12, |
|
|
mlp_ratio: float = 4.0, |
|
|
out_chans: int = 256, |
|
|
qkv_bias: bool = True, |
|
|
norm_layer: Type[nn.Module] = nn.LayerNorm, |
|
|
act_layer: Type[nn.Module] = nn.GELU, |
|
|
use_abs_pos: bool = True, |
|
|
use_rel_pos: bool = False, |
|
|
rel_pos_zero_init: bool = True, |
|
|
window_size: int = 0, |
|
|
global_attn_indexes: Tuple[int, ...] = (), |
|
|
) -> None: |
|
|
""" |
|
|
Args: |
|
|
img_size (int): Input image size. |
|
|
patch_size (int): Patch size. |
|
|
in_chans (int): Number of input image channels. |
|
|
embed_dim (int): Patch embedding dimension. |
|
|
depth (int): Depth of ViT. |
|
|
num_heads (int): Number of attention heads in each ViT block. |
|
|
mlp_ratio (float): Ratio of mlp hidden dim to embedding dim. |
|
|
qkv_bias (bool): If True, add a learnable bias to query, key, value. |
|
|
norm_layer (nn.Module): Normalization layer. |
|
|
act_layer (nn.Module): Activation layer. |
|
|
use_abs_pos (bool): If True, use absolute positional embeddings. |
|
|
use_rel_pos (bool): If True, add relative positional embeddings to the attention map. |
|
|
rel_pos_zero_init (bool): If True, zero initialize relative positional parameters. |
|
|
window_size (int): Window size for window attention blocks. |
|
|
global_attn_indexes (list): Indexes for blocks using global attention. |
|
|
""" |
|
|
super().__init__() |
|
|
self.img_size = img_size |
|
|
|
|
|
self.patch_embed = PatchEmbed( |
|
|
kernel_size=(patch_size, patch_size), |
|
|
stride=(patch_size, patch_size), |
|
|
in_chans=in_chans, |
|
|
embed_dim=embed_dim, |
|
|
) |
|
|
|
|
|
self.pos_embed: Optional[nn.Parameter] = None |
|
|
if use_abs_pos: |
|
|
|
|
|
self.pos_embed = nn.Parameter( |
|
|
torch.zeros(1, img_size // patch_size, img_size // patch_size, embed_dim) |
|
|
) |
|
|
|
|
|
self.blocks = nn.ModuleList() |
|
|
for i in range(depth): |
|
|
block = Block( |
|
|
dim=embed_dim, |
|
|
num_heads=num_heads, |
|
|
mlp_ratio=mlp_ratio, |
|
|
qkv_bias=qkv_bias, |
|
|
norm_layer=norm_layer, |
|
|
act_layer=act_layer, |
|
|
use_rel_pos=use_rel_pos, |
|
|
rel_pos_zero_init=rel_pos_zero_init, |
|
|
window_size=window_size if i not in global_attn_indexes else 0, |
|
|
input_size=(img_size // patch_size, img_size // patch_size), |
|
|
) |
|
|
self.blocks.append(block) |
|
|
|
|
|
self.neck = nn.Sequential( |
|
|
nn.Conv2d( |
|
|
embed_dim, |
|
|
out_chans, |
|
|
kernel_size=1, |
|
|
bias=False, |
|
|
), |
|
|
LayerNorm2d(out_chans), |
|
|
nn.Conv2d( |
|
|
out_chans, |
|
|
out_chans, |
|
|
kernel_size=3, |
|
|
padding=1, |
|
|
bias=False, |
|
|
), |
|
|
LayerNorm2d(out_chans), |
|
|
) |
|
|
|
|
|
self.net_2 = nn.Conv2d(256, 512, kernel_size=3, stride=2, padding=1, bias=False) |
|
|
self.net_3 = nn.Conv2d(512, 1024, kernel_size=3, stride=2, padding=1, bias=False) |
|
|
|
|
|
def forward(self, x: torch.Tensor) -> torch.Tensor: |
|
|
x = self.patch_embed(x) |
|
|
if self.pos_embed is not None: |
|
|
|
|
|
x = x + get_abs_pos_sam(self.pos_embed, x.size(1)) |
|
|
|
|
|
for blk in self.blocks: |
|
|
x = blk(x) |
|
|
|
|
|
x = self.neck(x.permute(0, 3, 1, 2)) |
|
|
x2 = self.net_2(x) |
|
|
x3 = self.net_3(x2.clone()) |
|
|
|
|
|
return x3 |
|
|
|
|
|
|
|
|
class Block(nn.Module): |
|
|
"""Transformer blocks with support of window attention and residual propagation blocks""" |
|
|
|
|
|
def __init__( |
|
|
self, |
|
|
dim: int, |
|
|
num_heads: int, |
|
|
mlp_ratio: float = 4.0, |
|
|
qkv_bias: bool = True, |
|
|
norm_layer: Type[nn.Module] = nn.LayerNorm, |
|
|
act_layer: Type[nn.Module] = nn.GELU, |
|
|
use_rel_pos: bool = False, |
|
|
rel_pos_zero_init: bool = True, |
|
|
window_size: int = 0, |
|
|
input_size: Optional[Tuple[int, int]] = None, |
|
|
) -> None: |
|
|
""" |
|
|
Args: |
|
|
dim (int): Number of input channels. |
|
|
num_heads (int): Number of attention heads in each ViT block. |
|
|
mlp_ratio (float): Ratio of mlp hidden dim to embedding dim. |
|
|
qkv_bias (bool): If True, add a learnable bias to query, key, value. |
|
|
norm_layer (nn.Module): Normalization layer. |
|
|
act_layer (nn.Module): Activation layer. |
|
|
use_rel_pos (bool): If True, add relative positional embeddings to the attention map. |
|
|
rel_pos_zero_init (bool): If True, zero initialize relative positional parameters. |
|
|
window_size (int): Window size for window attention blocks. If it equals 0, then |
|
|
use global attention. |
|
|
input_size (tuple(int, int) or None): Input resolution for calculating the relative |
|
|
positional parameter size. |
|
|
""" |
|
|
super().__init__() |
|
|
self.norm1 = norm_layer(dim) |
|
|
self.attn = Attention( |
|
|
dim, |
|
|
num_heads=num_heads, |
|
|
qkv_bias=qkv_bias, |
|
|
use_rel_pos=use_rel_pos, |
|
|
rel_pos_zero_init=rel_pos_zero_init, |
|
|
input_size=input_size if window_size == 0 else (window_size, window_size), |
|
|
) |
|
|
|
|
|
self.norm2 = norm_layer(dim) |
|
|
self.mlp = MLPBlock(embedding_dim=dim, mlp_dim=int(dim * mlp_ratio), act=act_layer) |
|
|
|
|
|
self.window_size = window_size |
|
|
|
|
|
def forward(self, x: torch.Tensor) -> torch.Tensor: |
|
|
shortcut = x |
|
|
x = self.norm1(x) |
|
|
|
|
|
if self.window_size > 0: |
|
|
H, W = x.shape[1], x.shape[2] |
|
|
x, pad_hw = window_partition(x, self.window_size) |
|
|
|
|
|
x = self.attn(x) |
|
|
|
|
|
if self.window_size > 0: |
|
|
x = window_unpartition(x, self.window_size, pad_hw, (H, W)) |
|
|
|
|
|
x = shortcut + x |
|
|
x = x + self.mlp(self.norm2(x)) |
|
|
|
|
|
return x |
|
|
|
|
|
|
|
|
class Attention(nn.Module): |
|
|
"""Multi-head Attention block with relative position embeddings.""" |
|
|
|
|
|
def __init__( |
|
|
self, |
|
|
dim: int, |
|
|
num_heads: int = 8, |
|
|
qkv_bias: bool = True, |
|
|
use_rel_pos: bool = False, |
|
|
rel_pos_zero_init: bool = True, |
|
|
input_size: Optional[Tuple[int, int]] = None, |
|
|
) -> None: |
|
|
""" |
|
|
Args: |
|
|
dim (int): Number of input channels. |
|
|
num_heads (int): Number of attention heads. |
|
|
qkv_bias (bool): If True, add a learnable bias to query, key, value. |
|
|
rel_pos (bool): If True, add relative positional embeddings to the attention map. |
|
|
rel_pos_zero_init (bool): If True, zero initialize relative positional parameters. |
|
|
input_size (tuple(int, int) or None): Input resolution for calculating the relative |
|
|
positional parameter size. |
|
|
""" |
|
|
super().__init__() |
|
|
self.num_heads = num_heads |
|
|
head_dim = dim // num_heads |
|
|
self.scale = head_dim**-0.5 |
|
|
|
|
|
self.qkv = nn.Linear(dim, dim * 3, bias=qkv_bias) |
|
|
self.proj = nn.Linear(dim, dim) |
|
|
|
|
|
self.use_rel_pos = use_rel_pos |
|
|
if self.use_rel_pos: |
|
|
assert ( |
|
|
input_size is not None |
|
|
), "Input size must be provided if using relative positional encoding." |
|
|
|
|
|
self.rel_pos_h = nn.Parameter(torch.zeros(2 * input_size[0] - 1, head_dim)) |
|
|
self.rel_pos_w = nn.Parameter(torch.zeros(2 * input_size[1] - 1, head_dim)) |
|
|
|
|
|
def forward(self, x: torch.Tensor) -> torch.Tensor: |
|
|
B, H, W, _ = x.shape |
|
|
|
|
|
qkv = self.qkv(x).reshape(B, H * W, 3, self.num_heads, -1).permute(2, 0, 3, 1, 4) |
|
|
|
|
|
q, k, v = qkv.reshape(3, B * self.num_heads, H * W, -1).unbind(0) |
|
|
|
|
|
rel_h, rel_w = None, None |
|
|
if self.use_rel_pos: |
|
|
rel_h, rel_w = add_decomposed_rel_pos(q, self.rel_pos_h, self.rel_pos_w, (H, W), (H, W)) |
|
|
|
|
|
q = q.view(B, self.num_heads, H * W, -1) |
|
|
k = k.view(B, self.num_heads, H * W, -1) |
|
|
v = v.view(B, self.num_heads, H * W, -1) |
|
|
|
|
|
if self.use_rel_pos: |
|
|
rel_h = rel_h.view(B, self.num_heads, rel_h.size(1), rel_h.size(2), rel_h.size(3)) |
|
|
rel_w = rel_w.view(B, self.num_heads, rel_w.size(1), rel_w.size(2), rel_w.size(3)) |
|
|
attn_bias = (rel_h + rel_w).view(B, self.num_heads, rel_h.size(2), rel_h.size(3) * rel_w.size(4)) |
|
|
x = torch.nn.functional.scaled_dot_product_attention(q, k, v, attn_mask=attn_bias) |
|
|
|
|
|
else: |
|
|
x = torch.nn.functional.scaled_dot_product_attention(q, k, v) |
|
|
|
|
|
x = x.view(B, self.num_heads, H, W, -1).permute(0, 2, 3, 1, 4).reshape(B, H, W, -1) |
|
|
|
|
|
x = self.proj(x) |
|
|
|
|
|
return x |
|
|
|
|
|
|
|
|
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). |
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|
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Returns: |
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Extracted positional embeddings according to relative positions. |
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""" |
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max_rel_dist = int(2 * max(q_size, k_size) - 1) |
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|
|
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if rel_pos.shape[0] != max_rel_dist: |
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|
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dtype = rel_pos.dtype |
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rel_pos = rel_pos.to(torch.float32) |
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rel_pos_resized = F.interpolate( |
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rel_pos.reshape(1, rel_pos.shape[0], -1).permute(0, 2, 1), |
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size=max_rel_dist, |
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|
mode="linear", |
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|
).to(dtype) |
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rel_pos_resized = rel_pos_resized.reshape(-1, max_rel_dist).permute(1, 0) |
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else: |
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rel_pos_resized = rel_pos |
|
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|
|
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|
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q_coords = torch.arange(q_size, device=rel_pos.device)[:, None] * max(k_size / q_size, 1.0) |
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k_coords = torch.arange(k_size, device=rel_pos.device)[None, :] * max(q_size / k_size, 1.0) |
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relative_coords = (q_coords - k_coords) + (k_size - 1) * max(q_size / k_size, 1.0) |
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|
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return rel_pos_resized[relative_coords.long()] |
|
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|
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|
|
def add_decomposed_rel_pos( |
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q: torch.Tensor, |
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rel_pos_h: torch.Tensor, |
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|
rel_pos_w: torch.Tensor, |
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|
q_size: Tuple[int, int], |
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|
k_size: Tuple[int, int], |
|
|
) -> torch.Tensor: |
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|
""" |
|
|
Calculate decomposed Relative Positional Embeddings from :paper:`mvitv2`. |
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|
https://github.com/facebookresearch/mvit/blob/19786631e330df9f3622e5402b4a419a263a2c80/mvit/models/attention.py # noqa B950 |
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|
Args: |
|
|
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). |
|
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|
|
|
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) |
|
|
rel_h = rel_h.unsqueeze(-1) |
|
|
rel_w = rel_w.unsqueeze(-2) |
|
|
rel_h = rel_h.reshape(B, q_h * q_w, k_h, 1) |
|
|
rel_w = rel_w.reshape(B, q_h * q_w, 1, k_w) |
|
|
|
|
|
return rel_h, rel_w |
|
|
|
|
|
|
|
|
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: |
|
|
x = self.proj(x) |
|
|
|
|
|
x = x.permute(0, 2, 3, 1) |
|
|
return x |
|
|
|
|
|
|
|
|
def build_sam_vit_b(checkpoint=None): |
|
|
return _build_sam( |
|
|
encoder_embed_dim=768, |
|
|
encoder_depth=12, |
|
|
encoder_num_heads=12, |
|
|
encoder_global_attn_indexes=[2, 5, 8, 11], |
|
|
checkpoint=checkpoint, |
|
|
) |
|
|
|
|
|
def build_sam_fast_vit_b(checkpoint=None, compile_mode='max-autotune', dtype=torch.bfloat16): |
|
|
image_encoder = build_sam_vit_b(checkpoint).eval().to(dtype) |
|
|
|
|
|
image_encoder = torch.compile(image_encoder, mode=compile_mode) |
|
|
return image_encoder |
|
|
|
|
|
|
|
|
def _build_sam( |
|
|
encoder_embed_dim, |
|
|
encoder_depth, |
|
|
encoder_num_heads, |
|
|
encoder_global_attn_indexes, |
|
|
checkpoint=None, |
|
|
): |
|
|
prompt_embed_dim = 256 |
|
|
image_size = 1024 |
|
|
vit_patch_size = 16 |
|
|
image_embedding_size = image_size // vit_patch_size |
|
|
image_encoder=ImageEncoderViT( |
|
|
depth=encoder_depth, |
|
|
embed_dim=encoder_embed_dim, |
|
|
img_size=image_size, |
|
|
mlp_ratio=4, |
|
|
norm_layer=partial(torch.nn.LayerNorm, eps=1e-6), |
|
|
num_heads=encoder_num_heads, |
|
|
patch_size=vit_patch_size, |
|
|
qkv_bias=True, |
|
|
use_rel_pos=True, |
|
|
global_attn_indexes=encoder_global_attn_indexes, |
|
|
window_size=14, |
|
|
out_chans=prompt_embed_dim, |
|
|
) |
|
|
image_encoder.eval() |
|
|
if checkpoint is not None: |
|
|
|
|
|
state_dict = torch.load(checkpoint) |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
image_encoder.load_state_dict({k[30:]: v for k, v in state_dict.items() if 'vision_tower_high' in k}, strict=True) |
|
|
print(checkpoint) |
|
|
return image_encoder |