diff options
| author | Volpeon <git@volpeon.ink> | 2022-10-26 11:11:33 +0200 |
|---|---|---|
| committer | Volpeon <git@volpeon.ink> | 2022-10-26 11:11:33 +0200 |
| commit | 49463992f48ec25f2ea31b220a6cedac3466467a (patch) | |
| tree | a58f40e558c14403dbeda687708ef334371694b8 /schedulers/scheduling_euler_a.py | |
| parent | Advanced datasets (diff) | |
| download | textual-inversion-diff-49463992f48ec25f2ea31b220a6cedac3466467a.tar.gz textual-inversion-diff-49463992f48ec25f2ea31b220a6cedac3466467a.tar.bz2 textual-inversion-diff-49463992f48ec25f2ea31b220a6cedac3466467a.zip | |
New Euler_a scheduler
Diffstat (limited to 'schedulers/scheduling_euler_a.py')
| -rw-r--r-- | schedulers/scheduling_euler_a.py | 286 |
1 files changed, 0 insertions, 286 deletions
diff --git a/schedulers/scheduling_euler_a.py b/schedulers/scheduling_euler_a.py deleted file mode 100644 index c097a8a..0000000 --- a/schedulers/scheduling_euler_a.py +++ /dev/null | |||
| @@ -1,286 +0,0 @@ | |||
| 1 | from typing import Optional, Tuple, Union | ||
| 2 | |||
| 3 | import numpy as np | ||
| 4 | import torch | ||
| 5 | |||
| 6 | from diffusers.configuration_utils import ConfigMixin, register_to_config | ||
| 7 | from diffusers.schedulers.scheduling_utils import SchedulerMixin, SchedulerOutput | ||
| 8 | |||
| 9 | |||
| 10 | class EulerAScheduler(SchedulerMixin, ConfigMixin): | ||
| 11 | """ | ||
| 12 | Stochastic sampling from Karras et al. [1] tailored to the Variance-Expanding (VE) models [2]. Use Algorithm 2 and | ||
| 13 | the VE column of Table 1 from [1] for reference. | ||
| 14 | |||
| 15 | [1] Karras, Tero, et al. "Elucidating the Design Space of Diffusion-Based Generative Models." | ||
| 16 | https://arxiv.org/abs/2206.00364 [2] Song, Yang, et al. "Score-based generative modeling through stochastic | ||
| 17 | differential equations." https://arxiv.org/abs/2011.13456 | ||
| 18 | |||
| 19 | [`~ConfigMixin`] takes care of storing all config attributes that are passed in the scheduler's `__init__` | ||
| 20 | function, such as `num_train_timesteps`. They can be accessed via `scheduler.config.num_train_timesteps`. | ||
| 21 | [`~ConfigMixin`] also provides general loading and saving functionality via the [`~ConfigMixin.save_config`] and | ||
| 22 | [`~ConfigMixin.from_config`] functions. | ||
| 23 | |||
| 24 | For more details on the parameters, see the original paper's Appendix E.: "Elucidating the Design Space of | ||
| 25 | Diffusion-Based Generative Models." https://arxiv.org/abs/2206.00364. The grid search values used to find the | ||
| 26 | optimal {s_noise, s_churn, s_min, s_max} for a specific model are described in Table 5 of the paper. | ||
| 27 | |||
| 28 | Args: | ||
| 29 | sigma_min (`float`): minimum noise magnitude | ||
| 30 | sigma_max (`float`): maximum noise magnitude | ||
| 31 | s_noise (`float`): the amount of additional noise to counteract loss of detail during sampling. | ||
| 32 | A reasonable range is [1.000, 1.011]. | ||
| 33 | s_churn (`float`): the parameter controlling the overall amount of stochasticity. | ||
| 34 | A reasonable range is [0, 100]. | ||
| 35 | s_min (`float`): the start value of the sigma range where we add noise (enable stochasticity). | ||
| 36 | A reasonable range is [0, 10]. | ||
| 37 | s_max (`float`): the end value of the sigma range where we add noise. | ||
| 38 | A reasonable range is [0.2, 80]. | ||
| 39 | |||
| 40 | """ | ||
| 41 | |||
| 42 | @register_to_config | ||
| 43 | def __init__( | ||
| 44 | self, | ||
| 45 | num_train_timesteps: int = 1000, | ||
| 46 | beta_start: float = 0.0001, | ||
| 47 | beta_end: float = 0.02, | ||
| 48 | beta_schedule: str = "linear", | ||
| 49 | trained_betas: Optional[np.ndarray] = None, | ||
| 50 | num_inference_steps=None, | ||
| 51 | device='cuda' | ||
| 52 | ): | ||
| 53 | if trained_betas is not None: | ||
| 54 | self.betas = torch.from_numpy(trained_betas).to(device) | ||
| 55 | if beta_schedule == "linear": | ||
| 56 | self.betas = torch.linspace(beta_start, beta_end, num_train_timesteps, dtype=torch.float32, device=device) | ||
| 57 | elif beta_schedule == "scaled_linear": | ||
| 58 | # this schedule is very specific to the latent diffusion model. | ||
| 59 | self.betas = torch.linspace(beta_start**0.5, beta_end**0.5, num_train_timesteps, | ||
| 60 | dtype=torch.float32, device=device) ** 2 | ||
| 61 | else: | ||
| 62 | raise NotImplementedError(f"{beta_schedule} does is not implemented for {self.__class__}") | ||
| 63 | |||
| 64 | self.device = device | ||
| 65 | |||
| 66 | self.alphas = 1.0 - self.betas | ||
| 67 | self.alphas_cumprod = torch.cumprod(self.alphas, dim=0) | ||
| 68 | |||
| 69 | # standard deviation of the initial noise distribution | ||
| 70 | self.init_noise_sigma = 1.0 | ||
| 71 | |||
| 72 | # setable values | ||
| 73 | self.num_inference_steps = num_inference_steps | ||
| 74 | self.timesteps = np.arange(0, num_train_timesteps)[::-1].copy() | ||
| 75 | # get sigmas | ||
| 76 | self.DSsigmas = ((1 - self.alphas_cumprod) / self.alphas_cumprod) ** 0.5 | ||
| 77 | self.sigmas = self.get_sigmas(self.DSsigmas, self.num_inference_steps) | ||
| 78 | |||
| 79 | # A# take number of steps as input | ||
| 80 | # A# store 1) number of steps 2) timesteps 3) schedule | ||
| 81 | |||
| 82 | def set_timesteps(self, num_inference_steps: int, device: Union[str, torch.device] = None, **kwargs): | ||
| 83 | """ | ||
| 84 | Sets the discrete timesteps used for the diffusion chain. Supporting function to be run before inference. | ||
| 85 | |||
| 86 | Args: | ||
| 87 | num_inference_steps (`int`): | ||
| 88 | the number of diffusion steps used when generating samples with a pre-trained model. | ||
| 89 | """ | ||
| 90 | |||
| 91 | self.num_inference_steps = num_inference_steps | ||
| 92 | self.DSsigmas = ((1 - self.alphas_cumprod) / self.alphas_cumprod) ** 0.5 | ||
| 93 | self.sigmas = self.get_sigmas(self.DSsigmas, self.num_inference_steps) | ||
| 94 | self.timesteps = self.sigmas[:-1] | ||
| 95 | self.is_scale_input_called = False | ||
| 96 | |||
| 97 | def scale_model_input(self, sample: torch.FloatTensor, timestep: int) -> torch.FloatTensor: | ||
| 98 | """ | ||
| 99 | Ensures interchangeability with schedulers that need to scale the denoising model input depending on the | ||
| 100 | current timestep. | ||
| 101 | Args: | ||
| 102 | sample (`torch.FloatTensor`): input sample | ||
| 103 | timestep (`int`, optional): current timestep | ||
| 104 | Returns: | ||
| 105 | `torch.FloatTensor`: scaled input sample | ||
| 106 | """ | ||
| 107 | if isinstance(timestep, torch.Tensor): | ||
| 108 | timestep = timestep.to(self.timesteps.device) | ||
| 109 | if self.is_scale_input_called: | ||
| 110 | return sample | ||
| 111 | step_index = (self.timesteps == timestep).nonzero().item() | ||
| 112 | sigma = self.sigmas[step_index] | ||
| 113 | sample = sample * sigma | ||
| 114 | self.is_scale_input_called = True | ||
| 115 | return sample | ||
| 116 | |||
| 117 | def step( | ||
| 118 | self, | ||
| 119 | model_output: torch.FloatTensor, | ||
| 120 | timestep: Union[float, torch.FloatTensor], | ||
| 121 | sample: torch.FloatTensor, | ||
| 122 | generator: torch.Generator = None, | ||
| 123 | return_dict: bool = True, | ||
| 124 | ) -> Union[SchedulerOutput, Tuple]: | ||
| 125 | """ | ||
| 126 | Predict the sample at the previous timestep by reversing the SDE. Core function to propagate the diffusion | ||
| 127 | process from the learned model outputs (most often the predicted noise). | ||
| 128 | |||
| 129 | Args: | ||
| 130 | model_output (`torch.FloatTensor`): direct output from learned diffusion model. | ||
| 131 | sigma_hat (`float`): TODO | ||
| 132 | sigma_prev (`float`): TODO | ||
| 133 | sample_hat (`torch.FloatTensor`): TODO | ||
| 134 | return_dict (`bool`): option for returning tuple rather than SchedulerOutput class | ||
| 135 | |||
| 136 | EulerAOutput: updated sample in the diffusion chain and derivative (TODO double check). | ||
| 137 | Returns: | ||
| 138 | [`~schedulers.scheduling_karras_ve.EulerAOutput`] or `tuple`: | ||
| 139 | [`~schedulers.scheduling_karras_ve.EulerAOutput`] if `return_dict` is True, otherwise a `tuple`. When | ||
| 140 | returning a tuple, the first element is the sample tensor. | ||
| 141 | |||
| 142 | """ | ||
| 143 | if isinstance(timestep, torch.Tensor): | ||
| 144 | timestep = timestep.to(self.timesteps.device) | ||
| 145 | step_index = (self.timesteps == timestep).nonzero().item() | ||
| 146 | step_prev_index = step_index + 1 | ||
| 147 | |||
| 148 | s = self.sigmas[step_index] | ||
| 149 | s_prev = self.sigmas[step_prev_index] | ||
| 150 | latents = sample | ||
| 151 | |||
| 152 | sigma_down, sigma_up = self.get_ancestral_step(s, s_prev) | ||
| 153 | d = self.to_d(latents, s, model_output) | ||
| 154 | dt = sigma_down - s | ||
| 155 | latents = latents + d * dt | ||
| 156 | latents = latents + torch.randn(latents.shape, layout=latents.layout, device=latents.device, dtype=latents.dtype, | ||
| 157 | generator=generator) * sigma_up | ||
| 158 | |||
| 159 | return SchedulerOutput(prev_sample=latents) | ||
| 160 | |||
| 161 | def step_correct( | ||
| 162 | self, | ||
| 163 | model_output: torch.FloatTensor, | ||
| 164 | sigma_hat: float, | ||
| 165 | sigma_prev: float, | ||
| 166 | sample_hat: torch.FloatTensor, | ||
| 167 | sample_prev: torch.FloatTensor, | ||
| 168 | derivative: torch.FloatTensor, | ||
| 169 | return_dict: bool = True, | ||
| 170 | ) -> Union[SchedulerOutput, Tuple]: | ||
| 171 | """ | ||
| 172 | Correct the predicted sample based on the output model_output of the network. TODO complete description | ||
| 173 | |||
| 174 | Args: | ||
| 175 | model_output (`torch.FloatTensor`): direct output from learned diffusion model. | ||
| 176 | sigma_hat (`float`): TODO | ||
| 177 | sigma_prev (`float`): TODO | ||
| 178 | sample_hat (`torch.FloatTensor`): TODO | ||
| 179 | sample_prev (`torch.FloatTensor`): TODO | ||
| 180 | derivative (`torch.FloatTensor`): TODO | ||
| 181 | return_dict (`bool`): option for returning tuple rather than SchedulerOutput class | ||
| 182 | |||
| 183 | Returns: | ||
| 184 | prev_sample (TODO): updated sample in the diffusion chain. derivative (TODO): TODO | ||
| 185 | |||
| 186 | """ | ||
| 187 | pred_original_sample = sample_prev + sigma_prev * model_output | ||
| 188 | derivative_corr = (sample_prev - pred_original_sample) / sigma_prev | ||
| 189 | sample_prev = sample_hat + (sigma_prev - sigma_hat) * (0.5 * derivative + 0.5 * derivative_corr) | ||
| 190 | |||
| 191 | if not return_dict: | ||
| 192 | return (sample_prev, derivative) | ||
| 193 | |||
| 194 | return SchedulerOutput(prev_sample=sample_prev) | ||
| 195 | |||
| 196 | def add_noise( | ||
| 197 | self, | ||
| 198 | original_samples: torch.FloatTensor, | ||
| 199 | noise: torch.FloatTensor, | ||
| 200 | timesteps: torch.FloatTensor, | ||
| 201 | ) -> torch.FloatTensor: | ||
| 202 | sigmas = self.sigmas.to(original_samples.device) | ||
| 203 | schedule_timesteps = self.timesteps.to(original_samples.device) | ||
| 204 | timesteps = timesteps.to(original_samples.device) | ||
| 205 | step_indices = [(schedule_timesteps == t).nonzero().item() for t in timesteps] | ||
| 206 | |||
| 207 | sigma = sigmas[step_indices].flatten() | ||
| 208 | while len(sigma.shape) < len(original_samples.shape): | ||
| 209 | sigma = sigma.unsqueeze(-1) | ||
| 210 | |||
| 211 | noisy_samples = original_samples + noise * sigma | ||
| 212 | self.is_scale_input_called = True | ||
| 213 | return noisy_samples | ||
| 214 | |||
| 215 | # from k_samplers sampling.py | ||
| 216 | |||
| 217 | def get_ancestral_step(self, sigma_from, sigma_to): | ||
| 218 | """Calculates the noise level (sigma_down) to step down to and the amount | ||
| 219 | of noise to add (sigma_up) when doing an ancestral sampling step.""" | ||
| 220 | sigma_up = (sigma_to ** 2 * (sigma_from ** 2 - sigma_to ** 2) / sigma_from ** 2) ** 0.5 | ||
| 221 | sigma_down = (sigma_to ** 2 - sigma_up ** 2) ** 0.5 | ||
| 222 | return sigma_down, sigma_up | ||
| 223 | |||
| 224 | def t_to_sigma(self, t, sigmas): | ||
| 225 | t = t.float() | ||
| 226 | low_idx, high_idx, w = t.floor().long(), t.ceil().long(), t.frac() | ||
| 227 | return (1 - w) * sigmas[low_idx] + w * sigmas[high_idx] | ||
| 228 | |||
| 229 | def append_zero(self, x): | ||
| 230 | return torch.cat([x, x.new_zeros([1])]) | ||
| 231 | |||
| 232 | def get_sigmas(self, sigmas, n=None): | ||
| 233 | if n is None: | ||
| 234 | return self.append_zero(sigmas.flip(0)) | ||
| 235 | t_max = len(sigmas) - 1 # = 999 | ||
| 236 | device = self.device | ||
| 237 | t = torch.linspace(t_max, 0, n, device=device) | ||
| 238 | # t = torch.linspace(t_max, 0, n, device=sigmas.device) | ||
| 239 | return self.append_zero(self.t_to_sigma(t, sigmas)) | ||
| 240 | |||
| 241 | # from k_samplers utils.py | ||
| 242 | def append_dims(self, x, target_dims): | ||
| 243 | """Appends dimensions to the end of a tensor until it has target_dims dimensions.""" | ||
| 244 | dims_to_append = target_dims - x.ndim | ||
| 245 | if dims_to_append < 0: | ||
| 246 | raise ValueError(f'input has {x.ndim} dims but target_dims is {target_dims}, which is less') | ||
| 247 | return x[(...,) + (None,) * dims_to_append] | ||
| 248 | |||
| 249 | # from k_samplers sampling.py | ||
| 250 | def to_d(self, x, sigma, denoised): | ||
| 251 | """Converts a denoiser output to a Karras ODE derivative.""" | ||
| 252 | return (x - denoised) / self.append_dims(sigma, x.ndim) | ||
| 253 | |||
| 254 | def get_scalings(self, sigma): | ||
| 255 | sigma_data = 1. | ||
| 256 | c_out = -sigma | ||
| 257 | c_in = 1 / (sigma ** 2 + sigma_data ** 2) ** 0.5 | ||
| 258 | return c_out, c_in | ||
| 259 | |||
| 260 | # DiscreteSchedule DS | ||
| 261 | def DSsigma_to_t(self, sigma, quantize=None): | ||
| 262 | # quantize = self.quantize if quantize is None else quantize | ||
| 263 | quantize = False | ||
| 264 | dists = torch.abs(sigma - self.DSsigmas[:, None]) | ||
| 265 | if quantize: | ||
| 266 | return torch.argmin(dists, dim=0).view(sigma.shape) | ||
| 267 | low_idx, high_idx = torch.sort(torch.topk(dists, dim=0, k=2, largest=False).indices, dim=0)[0] | ||
| 268 | low, high = self.DSsigmas[low_idx], self.DSsigmas[high_idx] | ||
| 269 | w = (low - sigma) / (low - high) | ||
| 270 | w = w.clamp(0, 1) | ||
| 271 | t = (1 - w) * low_idx + w * high_idx | ||
| 272 | return t.view(sigma.shape) | ||
| 273 | |||
| 274 | def prepare_input(self, latent_in, t, batch_size): | ||
| 275 | sigma = t.reshape(1) # A# potential bug: doesn't work on samples > 1 | ||
| 276 | |||
| 277 | sigma_in = torch.cat([sigma] * 2 * batch_size) | ||
| 278 | # noise_pred = CFGDenoiserForward(self.unet, latent_model_input, sigma_in, text_embeddings , guidance_scale,DSsigmas=self.scheduler.DSsigmas) | ||
| 279 | # noise_pred = DiscreteEpsDDPMDenoiserForward(self.unet,latent_model_input, sigma_in,DSsigmas=self.scheduler.DSsigmas, cond=cond_in) | ||
| 280 | c_out, c_in = [self.append_dims(x, latent_in.ndim) for x in self.get_scalings(sigma_in)] | ||
| 281 | |||
| 282 | sigma_in = self.DSsigma_to_t(sigma_in) | ||
| 283 | # s_in = latent_in.new_ones([latent_in.shape[0]]) | ||
| 284 | # sigma_in = sigma_in * s_in | ||
| 285 | |||
| 286 | return c_out, c_in, sigma_in | ||
