From 6c6c6636bb123d664999c888cda47a1f8bad635b Mon Sep 17 00:00:00 2001 From: Kyle Date: Fri, 3 Feb 2023 18:19:56 -0500 Subject: Image CFG Added (Full Implementation) Uses separate denoiser for edit (instruct-pix2pix) models No impact to txt2img or regular img2img "Image CFG Scale" will only apply to instruct-pix2pix models and metadata will only be added if using such model --- modules/sd_samplers_kdiffusion.py | 101 +++++++++++++++++++++++++++++++++++--- 1 file changed, 95 insertions(+), 6 deletions(-) (limited to 'modules/sd_samplers_kdiffusion.py') diff --git a/modules/sd_samplers_kdiffusion.py b/modules/sd_samplers_kdiffusion.py index aa7f106b..a16ba69b 100644 --- a/modules/sd_samplers_kdiffusion.py +++ b/modules/sd_samplers_kdiffusion.py @@ -1,6 +1,7 @@ from collections import deque import torch import inspect +import einops import k_diffusion.sampling from modules import prompt_parser, devices, sd_samplers_common @@ -40,6 +41,90 @@ sampler_extra_params = { 'sample_dpm_2': ['s_churn', 's_tmin', 's_tmax', 's_noise'], } +class CFGDenoiserEdit(torch.nn.Module): + """ + Classifier free guidance denoiser. A wrapper for stable diffusion model (specifically for unet) + that can take a noisy picture and produce a noise-free picture using two guidances (prompts) + instead of one. Originally, the second prompt is just an empty string, but we use non-empty + negative prompt. + """ + + def __init__(self, model): + super().__init__() + self.inner_model = model + self.mask = None + self.nmask = None + self.init_latent = None + self.step = 0 + + def combine_denoised(self, x_out, conds_list, uncond, cond_scale, image_cfg_scale): + denoised_uncond = x_out[-uncond.shape[0]:] + denoised = torch.clone(denoised_uncond) + + for i, conds in enumerate(conds_list): + for cond_index, weight in conds: + out_cond, out_img_cond, out_uncond = x_out.chunk(3) + denoised[i] = out_uncond[cond_index] + cond_scale * (out_cond[cond_index] - out_img_cond[cond_index]) + image_cfg_scale * (out_img_cond[cond_index] - out_uncond[cond_index]) + + return denoised + + def forward(self, x, sigma, uncond, cond, cond_scale, image_cond, image_cfg_scale): + if state.interrupted or state.skipped: + raise sd_samplers_common.InterruptedException + + conds_list, tensor = prompt_parser.reconstruct_multicond_batch(cond, self.step) + uncond = prompt_parser.reconstruct_cond_batch(uncond, self.step) + + batch_size = len(conds_list) + repeats = [len(conds_list[i]) for i in range(batch_size)] + + x_in = torch.cat([torch.stack([x[i] for _ in range(n)]) for i, n in enumerate(repeats)] + [x] + [x]) + sigma_in = torch.cat([torch.stack([sigma[i] for _ in range(n)]) for i, n in enumerate(repeats)] + [sigma] + [sigma]) + image_cond_in = torch.cat([torch.stack([image_cond[i] for _ in range(n)]) for i, n in enumerate(repeats)] + [image_cond] + [torch.zeros_like(self.init_latent)]) + + denoiser_params = CFGDenoiserParams(x_in, image_cond_in, sigma_in, state.sampling_step, state.sampling_steps) + cfg_denoiser_callback(denoiser_params) + x_in = denoiser_params.x + image_cond_in = denoiser_params.image_cond + sigma_in = denoiser_params.sigma + + if tensor.shape[1] == uncond.shape[1]: + cond_in = torch.cat([tensor, uncond, uncond]) + + if shared.batch_cond_uncond: + x_out = self.inner_model(x_in, sigma_in, cond={"c_crossattn": [cond_in], "c_concat": [image_cond_in]}) + else: + x_out = torch.zeros_like(x_in) + for batch_offset in range(0, x_out.shape[0], batch_size): + a = batch_offset + b = a + batch_size + x_out[a:b] = self.inner_model(x_in[a:b], sigma_in[a:b], cond={"c_crossattn": [cond_in[a:b]], "c_concat": [image_cond_in[a:b]]}) + else: + x_out = torch.zeros_like(x_in) + batch_size = batch_size*2 if shared.batch_cond_uncond else batch_size + for batch_offset in range(0, tensor.shape[0], batch_size): + a = batch_offset + b = min(a + batch_size, tensor.shape[0]) + x_out[a:b] = self.inner_model(x_in[a:b], sigma_in[a:b], cond={"c_crossattn": torch.cat([tensor[a:b]], uncond) , "c_concat": [image_cond_in[a:b]]}) + + x_out[-uncond.shape[0]:] = self.inner_model(x_in[-uncond.shape[0]:], sigma_in[-uncond.shape[0]:], cond={"c_crossattn": [uncond], "c_concat": [image_cond_in[-uncond.shape[0]:]]}) + + devices.test_for_nans(x_out, "unet") + + if opts.live_preview_content == "Prompt": + sd_samplers_common.store_latent(x_out[0:uncond.shape[0]]) + elif opts.live_preview_content == "Negative prompt": + sd_samplers_common.store_latent(x_out[-uncond.shape[0]:]) + + denoised = self.combine_denoised(x_out, conds_list, uncond, cond_scale, image_cfg_scale) + + if self.mask is not None: + denoised = self.init_latent * self.mask + self.nmask * denoised + + self.step += 1 + + return denoised + class CFGDenoiser(torch.nn.Module): """ @@ -78,8 +163,8 @@ class CFGDenoiser(torch.nn.Module): repeats = [len(conds_list[i]) for i in range(batch_size)] x_in = torch.cat([torch.stack([x[i] for _ in range(n)]) for i, n in enumerate(repeats)] + [x]) - image_cond_in = torch.cat([torch.stack([image_cond[i] for _ in range(n)]) for i, n in enumerate(repeats)] + [image_cond]) sigma_in = torch.cat([torch.stack([sigma[i] for _ in range(n)]) for i, n in enumerate(repeats)] + [sigma]) + image_cond_in = torch.cat([torch.stack([image_cond[i] for _ in range(n)]) for i, n in enumerate(repeats)] + [image_cond]) denoiser_params = CFGDenoiserParams(x_in, image_cond_in, sigma_in, state.sampling_step, state.sampling_steps) cfg_denoiser_callback(denoiser_params) @@ -160,7 +245,7 @@ class KDiffusionSampler: self.funcname = funcname self.func = getattr(k_diffusion.sampling, self.funcname) self.extra_params = sampler_extra_params.get(funcname, []) - self.model_wrap_cfg = CFGDenoiser(self.model_wrap) + self.model_wrap_cfg = CFGDenoiser(self.model_wrap) if not shared.sd_model.cond_stage_key == "edit" else CFGDenoiserEdit(self.model_wrap) self.sampler_noises = None self.stop_at = None self.eta = None @@ -260,13 +345,17 @@ class KDiffusionSampler: self.model_wrap_cfg.init_latent = x self.last_latent = x - - samples = self.launch_sampling(t_enc + 1, lambda: self.func(self.model_wrap_cfg, xi, extra_args={ + extra_args={ 'cond': conditioning, 'image_cond': image_conditioning, 'uncond': unconditional_conditioning, - 'cond_scale': p.cfg_scale - }, disable=False, callback=self.callback_state, **extra_params_kwargs)) + 'cond_scale': p.cfg_scale, + } + + if p.image_cfg_scale: + extra_args['image_cfg_scale'] = p.image_cfg_scale + + samples = self.launch_sampling(t_enc + 1, lambda: self.func(self.model_wrap_cfg, xi, extra_args=extra_args, disable=False, callback=self.callback_state, **extra_params_kwargs)) return samples -- cgit v1.2.1