Spaces:
Runtime error
Runtime error
""" Image to Patch Embedding using Conv2d | |
A convolution based approach to patchifying a 2D image w/ embedding projection. | |
Based on the impl in https://github.com/google-research/vision_transformer | |
Hacked together by / Copyright 2020 Ross Wightman | |
""" | |
from torch import nn as nn | |
from .helpers import to_2tuple | |
class PatchEmbed(nn.Module): | |
""" 2D Image to Patch Embedding | |
""" | |
def __init__(self, img_size=224, patch_size=16, in_chans=3, embed_dim=768, norm_layer=None, flatten=True): | |
super().__init__() | |
img_size = to_2tuple(img_size) | |
patch_size = to_2tuple(patch_size) | |
self.img_size = img_size | |
self.patch_size = patch_size | |
self.grid_size = (img_size[0] // patch_size[0], img_size[1] // patch_size[1]) | |
self.num_patches = self.grid_size[0] * self.grid_size[1] | |
self.flatten = flatten | |
self.proj = nn.Conv2d(in_chans, embed_dim, kernel_size=patch_size, stride=patch_size) | |
self.norm = norm_layer(embed_dim) if norm_layer else nn.Identity() | |
def forward(self, x): | |
B, C, H, W = x.shape | |
assert H == self.img_size[0] and W == self.img_size[1], \ | |
f"Input image size ({H}*{W}) doesn't match model ({self.img_size[0]}*{self.img_size[1]})." | |
x = self.proj(x) | |
if self.flatten: | |
x = x.flatten(2).transpose(1, 2) # BCHW -> BNC | |
x = self.norm(x) | |
return x | |