diff --git a/modules/sd_samplers_kdiffusion.py b/modules/sd_samplers_kdiffusion.py index 1bb25adf3..db7013f24 100644 --- a/modules/sd_samplers_kdiffusion.py +++ b/modules/sd_samplers_kdiffusion.py @@ -35,17 +35,15 @@ samplers_k_diffusion = [ @torch.no_grad() -def restart_sampler(model, x, sigmas, extra_args=None, callback=None, disable=None, s_noise=1., restart_list = {0.1: [10, 2, 2]}): +def restart_sampler(model, x, sigmas, extra_args=None, callback=None, disable=None, s_noise=1.): """Implements restart sampling in Restart Sampling for Improving Generative Processes (2023)""" '''Restart_list format: {min_sigma: [ restart_steps, restart_times, max_sigma]}''' - - from tqdm.auto import trange, tqdm + restart_list = {0.1: [10, 2, 2]} + from tqdm.auto import trange extra_args = {} if extra_args is None else extra_args s_in = x.new_ones([x.shape[0]]) step_id = 0 - from k_diffusion.sampling import to_d, append_zero - def heun_step(x, old_sigma, new_sigma): nonlocal step_id denoised = model(x, old_sigma * s_in, **extra_args) @@ -70,8 +68,6 @@ def restart_sampler(model, x, sigmas, extra_args=None, callback=None, disable=No for key, value in restart_list.items(): temp_list[int(torch.argmin(abs(sigmas - key), dim=0))] = value restart_list = temp_list - - def get_sigmas_karras(n, sigma_min, sigma_max, rho=7., device='cpu'): ramp = torch.linspace(0, 1, n).to(device) min_inv_rho = (sigma_min ** (1 / rho)) @@ -82,7 +78,6 @@ def restart_sampler(model, x, sigmas, extra_args=None, callback=None, disable=No max_inv_rho = max_inv_rho.to(device) sigmas = (max_inv_rho + ramp * (min_inv_rho - max_inv_rho)) ** rho return append_zero(sigmas).to(device) - for i in trange(len(sigmas) - 1, disable=disable): x = heun_step(x, sigmas[i], sigmas[i+1]) if i + 1 in restart_list: @@ -91,7 +86,8 @@ def restart_sampler(model, x, sigmas, extra_args=None, callback=None, disable=No max_idx = int(torch.argmin(abs(sigmas - restart_max), dim=0)) if max_idx < min_idx: sigma_restart = get_sigmas_karras(restart_steps, sigmas[min_idx], sigmas[max_idx], device=sigmas.device)[:-1] # remove the zero at the end - for times in range(restart_times): + while restart_times > 0: + restart_times -= 1 x = x + torch.randn_like(x) * s_noise * (sigmas[max_idx] ** 2 - sigmas[min_idx] ** 2) ** 0.5 for (old_sigma, new_sigma) in zip(sigma_restart[:-1], sigma_restart[1:]): x = heun_step(x, old_sigma, new_sigma)