imaginAIry/imaginairy/modules/clip_embedders.py
2022-09-11 22:22:43 -07:00

133 lines
3.5 KiB
Python

import kornia
import torch
import torch.nn as nn
from einops import repeat
from transformers import CLIPTextModel, CLIPTokenizer
from imaginairy.utils import get_device
from imaginairy.vendored import clip
class FrozenCLIPEmbedder(nn.Module):
"""Uses the CLIP transformer encoder for text (from Hugging Face)"""
def __init__(
self,
version="openai/clip-vit-large-patch14",
device=get_device(),
max_length=77,
):
super().__init__()
self.tokenizer = CLIPTokenizer.from_pretrained(version)
self.transformer = CLIPTextModel.from_pretrained(version)
self.device = device
self.max_length = max_length
self.freeze()
def freeze(self):
self.transformer = self.transformer.eval()
for param in self.parameters():
param.requires_grad = False
def forward(self, text):
batch_encoding = self.tokenizer(
text,
truncation=True,
max_length=self.max_length,
return_length=True,
return_overflowing_tokens=False,
padding="max_length",
return_tensors="pt",
)
tokens = batch_encoding["input_ids"].to(self.device)
outputs = self.transformer(input_ids=tokens)
z = outputs.last_hidden_state
return z
def encode(self, text):
return self(text)
class FrozenCLIPTextEmbedder(nn.Module):
"""
Uses the CLIP transformer encoder for text.
"""
def __init__(
self,
version="ViT-L/14",
device=get_device(),
max_length=77,
n_repeat=1,
normalize=True,
):
super().__init__()
self.model, _ = clip.load(version, jit=False, device=device)
self.device = device
self.max_length = max_length
self.n_repeat = n_repeat
self.normalize = normalize
def freeze(self):
self.model = self.model.eval()
for param in self.parameters():
param.requires_grad = False
def forward(self, text):
tokens = clip.tokenize(text).to(self.device)
z = self.model.encode_text(tokens)
if self.normalize:
z = z / torch.linalg.norm(z, dim=1, keepdim=True)
return z
def encode(self, text):
z = self(text)
if z.ndim == 2:
z = z[:, None, :]
z = repeat(z, "b 1 d -> b k d", k=self.n_repeat)
return z
class FrozenClipImageEmbedder(nn.Module):
"""
Uses the CLIP image encoder.
"""
def __init__(
self,
model_name,
jit=False,
device=get_device(),
antialias=False,
):
super().__init__()
self.model, preprocess = clip.load(name=model_name, device=device, jit=jit)
self.antialias = antialias
self.register_buffer(
"mean", torch.Tensor([0.48145466, 0.4578275, 0.40821073]), persistent=False
)
self.register_buffer(
"std", torch.Tensor([0.26862954, 0.26130258, 0.27577711]), persistent=False
)
def preprocess(self, x):
# normalize to [0,1]
x = kornia.geometry.resize(
x,
(224, 224),
interpolation="bicubic",
align_corners=True,
antialias=self.antialias,
)
x = (x + 1.0) / 2.0
# renormalize according to clip
x = kornia.enhance.normalize(x, self.mean, self.std)
return x
def forward(self, x):
# x is assumed to be in range [-1,1]
return self.model.encode_image(self.preprocess(x))