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dynamic thresholding (maybe?)

This commit is contained in:
rromb 2022-06-05 19:22:07 +02:00
parent 64cc718ead
commit a0f390afb6
2 changed files with 40 additions and 5 deletions
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41
ldm/models/diffusion/ddim.py
View File

@ -4,6 +4,7 @@ import torch
import numpy as np
from tqdm import tqdm
from functools import partial
from einops import rearrange
from ldm.modules.diffusionmodules.util import make_ddim_sampling_parameters, make_ddim_timesteps, noise_like
@ -73,8 +74,8 @@ class DDIMSampler(object):
x_T=None,
log_every_t=100,
unconditional_guidance_scale=1.,
unconditional_conditioning=None,
# this has to come in the same format as the conditioning, # e.g. as encoded tokens, ...
unconditional_conditioning=None, # this has to come in the same format as the conditioning, # e.g. as encoded tokens, ...
dynamic_threshold=None,
**kwargs
):
if conditioning is not None:
@ -106,6 +107,7 @@ class DDIMSampler(object):
log_every_t=log_every_t,
unconditional_guidance_scale=unconditional_guidance_scale,
unconditional_conditioning=unconditional_conditioning,
dynamic_threshold=dynamic_threshold,
)
return samples, intermediates
@ -115,7 +117,7 @@ class DDIMSampler(object):
callback=None, timesteps=None, quantize_denoised=False,
mask=None, x0=None, img_callback=None, log_every_t=100,
temperature=1., noise_dropout=0., score_corrector=None, corrector_kwargs=None,
unconditional_guidance_scale=1., unconditional_conditioning=None,):
unconditional_guidance_scale=1., unconditional_conditioning=None, dynamic_threshold=None):
device = self.model.betas.device
b = shape[0]
if x_T is None:
@ -150,7 +152,8 @@ class DDIMSampler(object):
noise_dropout=noise_dropout, score_corrector=score_corrector,
corrector_kwargs=corrector_kwargs,
unconditional_guidance_scale=unconditional_guidance_scale,
unconditional_conditioning=unconditional_conditioning)
unconditional_conditioning=unconditional_conditioning,
dynamic_threshold=dynamic_threshold)
img, pred_x0 = outs
if callback: callback(i)
if img_callback: img_callback(pred_x0, i)
@ -164,7 +167,8 @@ class DDIMSampler(object):
@torch.no_grad()
def p_sample_ddim(self, x, c, t, index, repeat_noise=False, use_original_steps=False, quantize_denoised=False,
temperature=1., noise_dropout=0., score_corrector=None, corrector_kwargs=None,
unconditional_guidance_scale=1., unconditional_conditioning=None):
unconditional_guidance_scale=1., unconditional_conditioning=None,
dynamic_threshold=None):
b, *_, device = *x.shape, x.device
if unconditional_conditioning is None or unconditional_guidance_scale == 1.:
@ -194,6 +198,33 @@ class DDIMSampler(object):
pred_x0 = (x - sqrt_one_minus_at * e_t) / a_t.sqrt()
if quantize_denoised:
pred_x0, _, *_ = self.model.first_stage_model.quantize(pred_x0)
if dynamic_threshold is not None:
# renorm
pred_max = pred_x0.max()
pred_min = pred_x0.min()
pred_x0 = (pred_x0-pred_min)/(pred_max-pred_min) # 0 ... 1
pred_x0 = 2*pred_x0 - 1. # -1 ... 1
s = torch.quantile(
rearrange(pred_x0, 'b ... -> b (...)').abs(),
dynamic_threshold,
dim=-1
)
s.clamp_(min=1.0)
s = s.view(-1, *((1,) * (pred_x0.ndim - 1)))
# clip by threshold
#pred_x0 = pred_x0.clamp(-s, s) / s # needs newer pytorch # TODO bring back to pure-gpu with min/max
# temporary hack: numpy on cpu
pred_x0 = np.clip(pred_x0.cpu().numpy(), -s.cpu().numpy(), s.cpu().numpy()) / s.cpu().numpy()
pred_x0 = torch.tensor(pred_x0).to(self.model.device)
# re.renorm
pred_x0 = (pred_x0 + 1.) / 2. # 0 ... 1
pred_x0 = (pred_max-pred_min)*pred_x0 + pred_min # orig range
# direction pointing to x_t
dir_xt = (1. - a_prev - sigma_t**2).sqrt() * e_t
noise = sigma_t * noise_like(x.shape, device, repeat_noise) * temperature

4
ldm/modules/encoders/modules.py
View File

@ -12,6 +12,10 @@ class AbstractEncoder(nn.Module):
def encode(self, *args, **kwargs):
raise NotImplementedError
class IdentityEncoder(AbstractEncoder):
def encode(self, x):
return x
class ClassEmbedder(nn.Module):