feat: add tcd sampler and discrete distilled tcd scheduler based on sgm_uniform (same as lcm) (#2907)

This commit is contained in:
Manuel Schmid
2024-05-19 13:08:33 +02:00
committed by GitHub
parent 3bae73e23e
commit 2e2e8f851a
8 changed files with 65 additions and 13 deletions
+27 -1
View File
@@ -752,7 +752,6 @@ def sample_lcm(model, x, sigmas, extra_args=None, callback=None, disable=None, n
return x
@torch.no_grad()
def sample_heunpp2(model, x, sigmas, extra_args=None, callback=None, disable=None, s_churn=0., s_tmin=0., s_tmax=float('inf'), s_noise=1.):
# From MIT licensed: https://github.com/Carzit/sd-webui-samplers-scheduler/
@@ -808,3 +807,30 @@ def sample_heunpp2(model, x, sigmas, extra_args=None, callback=None, disable=Non
d_prime = w1 * d + w2 * d_2 + w3 * d_3
x = x + d_prime * dt
return x
@torch.no_grad()
def sample_tcd(model, x, sigmas, extra_args=None, callback=None, disable=None, noise_sampler=None, eta=0.3):
extra_args = {} if extra_args is None else extra_args
noise_sampler = default_noise_sampler(x) if noise_sampler is None else noise_sampler
s_in = x.new_ones([x.shape[0]])
model_sampling = model.inner_model.inner_model.model_sampling
timesteps_s = torch.floor((1 - eta) * model_sampling.timestep(sigmas)).to(dtype=torch.long).detach().cpu()
timesteps_s[-1] = 0
alpha_prod_s = model_sampling.alphas_cumprod[timesteps_s]
beta_prod_s = 1 - alpha_prod_s
for i in trange(len(sigmas) - 1, disable=disable):
denoised = model(x, sigmas[i] * s_in, **extra_args) # predicted_original_sample
eps = (x - denoised) / sigmas[i]
denoised = alpha_prod_s[i + 1].sqrt() * denoised + beta_prod_s[i + 1].sqrt() * eps
if callback is not None:
callback({"x": x, "i": i, "sigma": sigmas[i], "sigma_hat": sigmas[i], "denoised": denoised})
x = denoised
if eta > 0 and sigmas[i + 1] > 0:
noise = noise_sampler(sigmas[i], sigmas[i + 1])
x = x / alpha_prod_s[i+1].sqrt() + noise * (sigmas[i+1]**2 + 1 - 1/alpha_prod_s[i+1]).sqrt()
return x