92 lines
3.0 KiB
Python
92 lines
3.0 KiB
Python
import dataclasses
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import torch
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import k_diffusion
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import numpy as np
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from modules import shared
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def to_d(x, sigma, denoised):
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"""Converts a denoiser output to a Karras ODE derivative."""
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return (x - denoised) / sigma
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k_diffusion.sampling.to_d = to_d
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@dataclasses.dataclass
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class Scheduler:
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name: str
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label: str
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function: any
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default_rho: float = -1
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need_inner_model: bool = False
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aliases: list = None
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def uniform(n, sigma_min, sigma_max, inner_model, device):
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return inner_model.get_sigmas(n).to(device)
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def sgm_uniform(n, sigma_min, sigma_max, inner_model, device):
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start = inner_model.sigma_to_t(torch.tensor(sigma_max))
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end = inner_model.sigma_to_t(torch.tensor(sigma_min))
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sigs = [
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inner_model.t_to_sigma(ts)
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for ts in torch.linspace(start, end, n + 1)[:-1]
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]
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sigs += [0.0]
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return torch.FloatTensor(sigs).to(device)
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def get_align_your_steps_sigmas(n, sigma_min, sigma_max, device):
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# https://research.nvidia.com/labs/toronto-ai/AlignYourSteps/howto.html
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def loglinear_interp(t_steps, num_steps):
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"""
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Performs log-linear interpolation of a given array of decreasing numbers.
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"""
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xs = np.linspace(0, 1, len(t_steps))
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ys = np.log(t_steps[::-1])
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new_xs = np.linspace(0, 1, num_steps)
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new_ys = np.interp(new_xs, xs, ys)
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interped_ys = np.exp(new_ys)[::-1].copy()
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return interped_ys
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if shared.sd_model.is_sdxl:
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sigmas = [14.615, 6.315, 3.771, 2.181, 1.342, 0.862, 0.555, 0.380, 0.234, 0.113, 0.029]
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else:
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# Default to SD 1.5 sigmas.
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sigmas = [14.615, 6.475, 3.861, 2.697, 1.886, 1.396, 0.963, 0.652, 0.399, 0.152, 0.029]
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if n != len(sigmas):
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sigmas = np.append(loglinear_interp(sigmas, n), [0.0])
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else:
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sigmas.append(0.0)
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return torch.FloatTensor(sigmas).to(device)
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def kl_optimal(n, sigma_min, sigma_max, device):
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alpha_min = torch.arctan(torch.tensor(sigma_min, device=device))
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alpha_max = torch.arctan(torch.tensor(sigma_max, device=device))
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step_indices = torch.arange(n + 1, device=device)
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sigmas = torch.tan(step_indices / n * alpha_min + (1.0 - step_indices / n) * alpha_max)
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return sigmas
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schedulers = [
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Scheduler('automatic', 'Automatic', None),
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Scheduler('uniform', 'Uniform', uniform, need_inner_model=True),
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Scheduler('karras', 'Karras', k_diffusion.sampling.get_sigmas_karras, default_rho=7.0),
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Scheduler('exponential', 'Exponential', k_diffusion.sampling.get_sigmas_exponential),
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Scheduler('polyexponential', 'Polyexponential', k_diffusion.sampling.get_sigmas_polyexponential, default_rho=1.0),
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Scheduler('sgm_uniform', 'SGM Uniform', sgm_uniform, need_inner_model=True, aliases=["SGMUniform"]),
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Scheduler('kl_optimal', 'KL Optimal', kl_optimal),
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Scheduler('align_your_steps', 'Align Your Steps', get_align_your_steps_sigmas),
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]
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schedulers_map = {**{x.name: x for x in schedulers}, **{x.label: x for x in schedulers}}
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