stable-diffusion-webui/modules/sd_schedulers.py
drhead 3a215deff2
vectorize kl-optimal sigma calculation
Co-authored-by: mamei16 <marcel.1710@live.de>
2024-04-28 00:15:58 -04:00

53 lines
1.7 KiB
Python

import dataclasses
import torch
import k_diffusion
@dataclasses.dataclass
class Scheduler:
name: str
label: str
function: any
default_rho: float = -1
need_inner_model: bool = False
aliases: list = None
def uniform(n, sigma_min, sigma_max, inner_model, device):
return inner_model.get_sigmas(n)
def sgm_uniform(n, sigma_min, sigma_max, inner_model, device):
start = inner_model.sigma_to_t(torch.tensor(sigma_max))
end = inner_model.sigma_to_t(torch.tensor(sigma_min))
sigs = [
inner_model.t_to_sigma(ts)
for ts in torch.linspace(start, end, n + 1)[:-1]
]
sigs += [0.0]
return torch.FloatTensor(sigs).to(device)
def kl_optimal(n, sigma_min, sigma_max, device):
alpha_min = torch.arctan(torch.tensor(sigma_min, device=device))
alpha_max = torch.arctan(torch.tensor(sigma_max, device=device))
step_indices = torch.arange(n + 1, device=device)
sigmas = torch.tan(step_indices / n * alpha_min + (1.0 - step_indices / n) * alpha_max)
return sigmas
schedulers = [
Scheduler('automatic', 'Automatic', None),
Scheduler('uniform', 'Uniform', uniform, need_inner_model=True),
Scheduler('karras', 'Karras', k_diffusion.sampling.get_sigmas_karras, default_rho=7.0),
Scheduler('exponential', 'Exponential', k_diffusion.sampling.get_sigmas_exponential),
Scheduler('polyexponential', 'Polyexponential', k_diffusion.sampling.get_sigmas_polyexponential, default_rho=1.0),
Scheduler('sgm_uniform', 'SGM Uniform', sgm_uniform, need_inner_model=True, aliases=["SGMUniform"]),
Scheduler('kl_optimal', 'KL Optimal', kl_optimal),
]
schedulers_map = {**{x.name: x for x in schedulers}, **{x.label: x for x in schedulers}}