|
| 1 | +from shutil import rmtree |
| 2 | +from pathlib import Path |
| 3 | + |
| 4 | +import torch |
| 5 | +from torch import nn, tensor, Tensor |
| 6 | +from torch.nn import Module |
| 7 | +from torch.utils.data import Dataset, DataLoader |
| 8 | +from torch.optim import Adam |
| 9 | + |
| 10 | +from einops import rearrange |
| 11 | + |
| 12 | +import torchvision |
| 13 | +import torchvision.transforms as T |
| 14 | +from torchvision.utils import save_image |
| 15 | + |
| 16 | +from transfusion_pytorch import Transfusion, print_modality_sample |
| 17 | + |
| 18 | +# hf related |
| 19 | + |
| 20 | +from datasets import load_dataset |
| 21 | +from diffusers.models import AutoencoderKL |
| 22 | + |
| 23 | +vae = AutoencoderKL.from_pretrained("CompVis/stable-diffusion-v1-4", subfolder = "vae") |
| 24 | + |
| 25 | +class Encoder(Module): |
| 26 | + def __init__(self, vae): |
| 27 | + super().__init__() |
| 28 | + self.vae = vae |
| 29 | + |
| 30 | + def forward(self, image): |
| 31 | + with torch.no_grad(): |
| 32 | + latent = self.vae.encode(image * 2 - 1) |
| 33 | + |
| 34 | + return 0.18215 * latent.latent_dist.sample() |
| 35 | + |
| 36 | +class Decoder(Module): |
| 37 | + def __init__(self, vae): |
| 38 | + super().__init__() |
| 39 | + self.vae = vae |
| 40 | + |
| 41 | + def forward(self, latents): |
| 42 | + latents = (1 / 0.18215) * latents |
| 43 | + |
| 44 | + with torch.no_grad(): |
| 45 | + image = self.vae.decode(latents).sample |
| 46 | + |
| 47 | + return (image / 2 + 0.5).clamp(0, 1) |
| 48 | + |
| 49 | +# results folder |
| 50 | + |
| 51 | +rmtree('./results', ignore_errors = True) |
| 52 | +results_folder = Path('./results') |
| 53 | +results_folder.mkdir(exist_ok = True, parents = True) |
| 54 | + |
| 55 | +# constants |
| 56 | + |
| 57 | +SAMPLE_EVERY = 100 |
| 58 | + |
| 59 | +with open("./data/flowers/labels.txt", "r") as file: |
| 60 | + content = file.read() |
| 61 | + |
| 62 | +LABELS_TEXT = content.split('\n') |
| 63 | + |
| 64 | +# functions |
| 65 | + |
| 66 | +def divisible_by(num, den): |
| 67 | + return (num % den) == 0 |
| 68 | + |
| 69 | +def decode_token(token): |
| 70 | + return str(chr(max(32, token))) |
| 71 | + |
| 72 | +def decode_tokens(tokens: Tensor) -> str: |
| 73 | + return "".join(list(map(decode_token, tokens.tolist()))) |
| 74 | + |
| 75 | +def encode_tokens(str: str) -> Tensor: |
| 76 | + return tensor([*bytes(str, 'UTF-8')]) |
| 77 | + |
| 78 | +# encoder / decoder |
| 79 | + |
| 80 | +model = Transfusion( |
| 81 | + num_text_tokens = 256, |
| 82 | + dim_latent = 4, |
| 83 | + channel_first_latent = True, |
| 84 | + modality_default_shape = (4, 4), |
| 85 | + modality_encoder = Encoder(vae), |
| 86 | + modality_decoder = Decoder(vae), |
| 87 | + pre_post_transformer_enc_dec = ( |
| 88 | + nn.Conv2d(4, 128, 3, 2, 1), |
| 89 | + nn.ConvTranspose2d(128, 4, 3, 2, 1, output_padding = 1), |
| 90 | + ), |
| 91 | + add_pos_emb = True, |
| 92 | + modality_num_dim = 2, |
| 93 | + velocity_consistency_loss_weight = 0.1, |
| 94 | + reconstruction_loss_weight = 0.1, |
| 95 | + transformer = dict( |
| 96 | + dim = 128, |
| 97 | + depth = 8, |
| 98 | + dim_head = 64, |
| 99 | + heads = 8 |
| 100 | + ) |
| 101 | +).cuda() |
| 102 | + |
| 103 | +ema_model = model.create_ema(0.9) |
| 104 | + |
| 105 | +class FlowersDataset(Dataset): |
| 106 | + def __init__(self, image_size): |
| 107 | + self.ds = load_dataset("nelorth/oxford-flowers")['train'] |
| 108 | + |
| 109 | + self.transform = T.Compose([ |
| 110 | + T.Resize((image_size, image_size)), |
| 111 | + T.PILToTensor(), |
| 112 | + T.Lambda(lambda t: t / 255.) |
| 113 | + ]) |
| 114 | + |
| 115 | + def __len__(self): |
| 116 | + return len(self.ds) |
| 117 | + |
| 118 | + def __getitem__(self, idx): |
| 119 | + sample = self.ds[idx] |
| 120 | + pil = sample['image'] |
| 121 | + |
| 122 | + labels_int = sample['label'] |
| 123 | + labels_text = LABELS_TEXT[labels_int] |
| 124 | + |
| 125 | + tensor = self.transform(pil) |
| 126 | + return encode_tokens(labels_text), tensor |
| 127 | + |
| 128 | +def cycle(iter_dl): |
| 129 | + while True: |
| 130 | + for batch in iter_dl: |
| 131 | + yield batch |
| 132 | + |
| 133 | +dataset = FlowersDataset(128) |
| 134 | + |
| 135 | +dataloader = model.create_dataloader(dataset, batch_size = 4, shuffle = True) |
| 136 | + |
| 137 | +iter_dl = cycle(dataloader) |
| 138 | + |
| 139 | +optimizer = Adam(model.parameters(), lr = 8e-4) |
| 140 | + |
| 141 | +# train loop |
| 142 | + |
| 143 | +for step in range(1, 100_000 + 1): |
| 144 | + |
| 145 | + for _ in range(4): |
| 146 | + loss = model.forward(next(iter_dl)) |
| 147 | + (loss / 4).backward() |
| 148 | + |
| 149 | + torch.nn.utils.clip_grad_norm_(model.parameters(), 0.5) |
| 150 | + |
| 151 | + optimizer.step() |
| 152 | + optimizer.zero_grad() |
| 153 | + |
| 154 | + ema_model.update() |
| 155 | + |
| 156 | + print(f'{step}: {loss.item():.3f}') |
| 157 | + |
| 158 | + if divisible_by(step, SAMPLE_EVERY): |
| 159 | + sample = ema_model.sample() |
| 160 | + |
| 161 | + print_modality_sample(sample) |
| 162 | + |
| 163 | + if len(sample) < 3: |
| 164 | + continue |
| 165 | + |
| 166 | + text_tensor, maybe_image, *_ = sample |
| 167 | + |
| 168 | + if not isinstance(maybe_image, tuple): |
| 169 | + continue |
| 170 | + |
| 171 | + _, image = maybe_image |
| 172 | + text_tensor = text_tensor[text_tensor < 256] # todo: offer a utility function for removing meta tags and special tokens |
| 173 | + |
| 174 | + text = decode_tokens(text_tensor) |
| 175 | + filename = str(results_folder / f'{text}.{step}.png') |
| 176 | + |
| 177 | + save_image( |
| 178 | + image.detach().cpu(), |
| 179 | + filename |
| 180 | + ) |
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