198 lines
6.2 KiB
Python
198 lines
6.2 KiB
Python
import math
|
|
from math import sqrt
|
|
|
|
import torch
|
|
import torch.nn as nn
|
|
import torch.nn.functional as F
|
|
from einops import rearrange
|
|
from torch import einsum
|
|
|
|
from models.vqvae.vqvae import Quantize
|
|
from trainer.networks import register_model
|
|
from utils.util import opt_get
|
|
|
|
|
|
def default(val, d):
|
|
return val if val is not None else d
|
|
|
|
|
|
def eval_decorator(fn):
|
|
def inner(model, *args, **kwargs):
|
|
was_training = model.training
|
|
model.eval()
|
|
out = fn(model, *args, **kwargs)
|
|
model.train(was_training)
|
|
return out
|
|
return inner
|
|
|
|
|
|
class ResBlock(nn.Module):
|
|
def __init__(self, chan, conv):
|
|
super().__init__()
|
|
self.net = nn.Sequential(
|
|
conv(chan, chan, 3, padding = 1),
|
|
nn.ReLU(),
|
|
conv(chan, chan, 3, padding = 1),
|
|
nn.ReLU(),
|
|
conv(chan, chan, 1)
|
|
)
|
|
|
|
def forward(self, x):
|
|
return self.net(x) + x
|
|
|
|
|
|
class DiscreteVAE(nn.Module):
|
|
def __init__(
|
|
self,
|
|
positional_dims=2,
|
|
num_tokens = 512,
|
|
codebook_dim = 512,
|
|
num_layers = 3,
|
|
num_resnet_blocks = 0,
|
|
hidden_dim = 64,
|
|
channels = 3,
|
|
smooth_l1_loss = False,
|
|
straight_through = False,
|
|
normalization = None, # ((0.5,) * 3, (0.5,) * 3),
|
|
record_codes = False,
|
|
):
|
|
super().__init__()
|
|
assert num_layers >= 1, 'number of layers must be greater than or equal to 1'
|
|
has_resblocks = num_resnet_blocks > 0
|
|
|
|
self.num_tokens = num_tokens
|
|
self.num_layers = num_layers
|
|
self.straight_through = straight_through
|
|
self.codebook = Quantize(num_tokens, codebook_dim)
|
|
self.positional_dims = positional_dims
|
|
|
|
assert positional_dims > 0 and positional_dims < 3 # This VAE only supports 1d and 2d inputs for now.
|
|
if positional_dims == 2:
|
|
conv = nn.Conv2d
|
|
conv_transpose = nn.ConvTranspose2d
|
|
else:
|
|
conv = nn.Conv1d
|
|
conv_transpose = nn.ConvTranspose1d
|
|
|
|
enc_chans = [hidden_dim] * num_layers
|
|
dec_chans = list(reversed(enc_chans))
|
|
|
|
enc_chans = [channels, *enc_chans]
|
|
|
|
dec_init_chan = codebook_dim if not has_resblocks else dec_chans[0]
|
|
dec_chans = [dec_init_chan, *dec_chans]
|
|
|
|
enc_chans_io, dec_chans_io = map(lambda t: list(zip(t[:-1], t[1:])), (enc_chans, dec_chans))
|
|
|
|
enc_layers = []
|
|
dec_layers = []
|
|
|
|
for (enc_in, enc_out), (dec_in, dec_out) in zip(enc_chans_io, dec_chans_io):
|
|
enc_layers.append(nn.Sequential(conv(enc_in, enc_out, 4, stride = 2, padding = 1), nn.ReLU()))
|
|
dec_layers.append(nn.Sequential(conv_transpose(dec_in, dec_out, 4, stride = 2, padding = 1), nn.ReLU()))
|
|
|
|
for _ in range(num_resnet_blocks):
|
|
dec_layers.insert(0, ResBlock(dec_chans[1], conv))
|
|
enc_layers.append(ResBlock(enc_chans[-1], conv))
|
|
|
|
if num_resnet_blocks > 0:
|
|
dec_layers.insert(0, conv(codebook_dim, dec_chans[1], 1))
|
|
|
|
enc_layers.append(conv(enc_chans[-1], num_tokens, 1))
|
|
dec_layers.append(conv(dec_chans[-1], channels, 1))
|
|
|
|
self.encoder = nn.Sequential(*enc_layers)
|
|
self.decoder = nn.Sequential(*dec_layers)
|
|
|
|
self.loss_fn = F.smooth_l1_loss if smooth_l1_loss else F.mse_loss
|
|
|
|
# take care of normalization within class
|
|
self.normalization = normalization
|
|
self.record_codes = record_codes
|
|
if record_codes:
|
|
self.codes = torch.zeros((32768,), dtype=torch.long)
|
|
self.code_ind = 0
|
|
|
|
def norm(self, images):
|
|
if not self.normalization is not None:
|
|
return images
|
|
|
|
means, stds = map(lambda t: torch.as_tensor(t).to(images), self.normalization)
|
|
arrange = 'c -> () c () ()' if self.positional_dims == 2 else 'c -> () c ()'
|
|
means, stds = map(lambda t: rearrange(t, arrange), (means, stds))
|
|
images = images.clone()
|
|
images.sub_(means).div_(stds)
|
|
return images
|
|
|
|
def get_debug_values(self, step, __):
|
|
if self.record_codes:
|
|
# Report annealing schedule
|
|
return {'histogram_codes': self.codes}
|
|
else:
|
|
return {}
|
|
|
|
@torch.no_grad()
|
|
@eval_decorator
|
|
def get_codebook_indices(self, images):
|
|
img = self.norm(images)
|
|
logits = self.encoder(img).permute((0,2,3,1) if len(img.shape) == 4 else (0,2,1))
|
|
sampled, commitment_loss, codes = self.codebook(logits)
|
|
return codes
|
|
|
|
def decode(
|
|
self,
|
|
img_seq
|
|
):
|
|
image_embeds = self.codebook.embed_code(img_seq)
|
|
b, n, d = image_embeds.shape
|
|
|
|
kwargs = {}
|
|
if self.positional_dims == 1:
|
|
arrange = 'b n d -> b d n'
|
|
else:
|
|
h = w = int(sqrt(n))
|
|
arrange = 'b (h w) d -> b d h w'
|
|
kwargs = {'h': h, 'w': w}
|
|
image_embeds = rearrange(image_embeds, arrange, **kwargs)
|
|
images = self.decoder(image_embeds)
|
|
return images
|
|
|
|
def forward(
|
|
self,
|
|
img
|
|
):
|
|
img = self.norm(img)
|
|
logits = self.encoder(img).permute((0,2,3,1) if len(img.shape) == 4 else (0,2,1))
|
|
sampled, commitment_loss, codes = self.codebook(logits)
|
|
sampled = sampled.permute((0,3,1,2) if len(img.shape) == 4 else (0,2,1))
|
|
out = self.decoder(sampled)
|
|
|
|
# reconstruction loss
|
|
recon_loss = self.loss_fn(img, out)
|
|
|
|
# This is so we can debug the distribution of codes being learned.
|
|
if self.record_codes:
|
|
codes = codes.flatten()
|
|
l = codes.shape[0]
|
|
i = self.code_ind if (self.codes.shape[0] - self.code_ind) > l else self.codes.shape[0] - l
|
|
self.codes[i:i+l] = codes.cpu()
|
|
self.code_ind = self.code_ind + l
|
|
if self.code_ind >= self.codes.shape[0]:
|
|
self.code_ind = 0
|
|
|
|
return recon_loss, commitment_loss, out
|
|
|
|
|
|
@register_model
|
|
def register_lucidrains_dvae(opt_net, opt):
|
|
return DiscreteVAE(**opt_get(opt_net, ['kwargs'], {}))
|
|
|
|
|
|
if __name__ == '__main__':
|
|
#v = DiscreteVAE()
|
|
#o=v(torch.randn(1,3,256,256))
|
|
#print(o.shape)
|
|
v = DiscreteVAE(channels=1, normalization=None, positional_dims=1)
|
|
o=v(torch.randn(1,1,256))
|
|
print(o[-1].shape)
|