Agent Conversation: google/gemini-3.1-pro-preview
Task: cv-diffusion-efficiency
Diffusion Model: Sampler Efficiency Optimization
Objective
Design an efficient numerical sampler for text-to-image diffusion models that achieves the lowest possible FID at a fixed sampling budget. This is a pure ODE/SDE solver task — image-text alignment is not the metric.
Background
Diffusion models generate images by integrating a probability-flow ODE (or reverse SDE) from random noise toward the data distribution. Different numerical solvers reach different points on the cost vs. quality Pareto frontier.
Standard solver families:
- DDIM (Song et al 2021) — first-order ODE solver, deterministic
- Euler / Heun — explicit Runge-Kutta family
- DPM-Solver / DPM-Solver++ (Lu et al 2022) — exponential integrators specialized for the diffusion ODE; 1st / 2nd / 3rd order, single-step or multistep
- UniPC (Zhao et al 2023) — predictor-corrector unified framework
- EDM Heun (Karras et al 2022) — second-order Heun on the EDM ODE form
The core sampling loop follows this pattern:
for step, t in enumerate(timesteps):
# 1. Predict noise (one network forward pass = 1 NFE)
noise_pred = self.predict_noise(zt, t, uncond, cond)
# 2. Tweedie's formula: estimate clean latent
z0t = (zt - sigma_t * noise_pred) / alpha_t
# 3. Update rule — THIS is what you must redesign
zt_next = update_rule(zt, z0t, noise_pred, t, t_next, history=...)
The update_rule is the only thing that distinguishes a first-order DDIM step from a second-order DPM-Solver++ step. Your job is to design a better one.
Task
Replace the update_rule inside BaseDDIMCFGpp.sample() (SD v1.5) and BaseDDIMCFGpp.reverse_process() (SDXL) with a higher-quality numerical integration scheme that produces lower FID at the fixed NFE budget.
Hard rules — read carefully
-
cfg_guidanceis fixed at 1.0 in all evaluation runs. You must not:- rescale, modulate, or reweight the CFG-combined noise prediction
- exploit asymmetry between
noise_ucandnoise_cto leak conditional information into the renoising direction - apply any "rescaled CFG" / "CFG normalization" / "guidance phi mixing" technique
- assume your sampler runs at any other guidance value The task is not about classifier-free guidance. Treat the noise prediction the model gives you as fixed; your contribution lives entirely in the time-stepping.
-
No image post-processing tricks. The metric is FID on the generated image distribution. You may not:
- apply dynamic thresholding, percentile clipping, or amplitude clamping to
z0torzt - apply EMA / momentum / smoothing across denoising steps
- apply any per-sample normalization that depends on the predicted clean latent These are heuristics that change the output distribution but do not improve the underlying solver. They are out of scope.
- apply dynamic thresholding, percentile clipping, or amplitude clamping to
-
The contribution must be a numerical-integration improvement, e.g.:
- higher-
Tool Input
1{
2 "end_line": 682,
3 "start_line": 622,
4 "filename": "CFGpp-main/latent_diffusion.py",
5 "op": "replace",
6 "content": "class BaseDDIMCFGpp(StableDiffusion):\n def __init__(self,\n solver_config: Dict,\n model_key:str=\"runwayml/stable-diffusion-v1-5\",\n device: Optional[torch.device]=None,\n **kwargs):\n super().__init__(solver_config, model_key, device, **kwargs)\n\n @torch.autocast(device_type='cuda', dtype=torch.float16)\n def sample(self,\n cfg_guidance=1.0,\n prompt=[\"\",\"\"],\n callback_fn=None,\n **kwargs):\n \n t_fn = lambda sigma: sigma.log().neg()\n \n uc, c = self.get_text_embed(null_prompt=prompt[0], prompt=prompt[1])\n \n total_sigmas = (1-self.total_alphas).sqrt() / self.total_alphas.sqrt()\n sigmas = get_sigmas_karras(len(self.scheduler.timesteps), total_sigmas.min(), total_sigmas.max(), rho=7., device=self.device)\n \n x = self.initialize_latent(method=\"random_kdiffusion\",\n latent_dim=(1, 4, 64, 64),\n sigmas=sigmas).to(self.dtype)\n \n old_denoised = None\n \n pbar = tqdm(self.scheduler.timesteps, desc=\"DPM++2M-SDE Exact\")\n for i, _ in enumerate(pbar):\n sigma = sigmas[i]\n new_t = self.timestep(sigma).to(self.device)\n \n with torch.no_grad():\n denoised, _ = self.kdiffusion_x_to_denoised(x, sigma, uc, c, cfg_guidance, new_t)\n \n sigma_down, sigma_up = self.get_ancestral_step(sigmas[i], sigmas[i + 1], eta=1.0)\n \n if sigma_down == 0:\n d = self.to_d(x, sigmas[i], denoised)\n x = denoised + d * sigma_down\n else:\n t = t_fn(sigmas[i])\n t_next = t_fn(sigma_down)\n h = t_next - t\n \n h_f32 = h.float()\n I_0_f32 = -(-h_f32).expm1()\n I_1_f32 = h_f32 - I_0_f32\n \n I_0 = I_0_f32.to(h.dtype)\n I_1 = I_1_f32.to(h.dtype)\n \n if old_denoised is None:\n x = torch.exp(-h) * x + I_0 * denoised\n else:\n h_last = t - t_fn(sigmas[i-1])\n p_n = (denoised - old_denoised) / h_last\n x = torch.exp(-h) * x + I_0 * denoised + I_1 * p_n\n \n if sigmas[i + 1] > 0:\n x = x + torch.randn_like(x) * sigma_up\n \n old_denoised = denoised\n\n if callback_fn is not None:\n callback_kwargs = {'z0t': denoised.detach(),\n 'zt': x.detach(),\n 'decode': self.decode}\n callback_kwargs = callback_fn(i, new_t, callback_kwargs)\n denoised = callback_kwargs[\"z0t\"]\n x = callback_kwargs[\"zt\"]\n\n img = self.decode(x)\n img = (img / 2 + 0.5).clamp(0, 1)\n return img.detach().cpu()"
7}ERROR: Lines 622..682 exceed the editable range. You may only edit lines 624–682.
[Current file: CFGpp-main/latent_diffusion.py | editable: 624–682 | total: 1021 lines]
621| @register_solver("ddim_cfg++")
622| class BaseDDIMCFGpp(StableDiffusion):
623| # TODO: Implement your improved sampling method here.
624 #
625 # You should implement an improved sampling algorithm that achieves better
626 # image-text alignment (CLIP score) with a fixed budget of NFE=20 steps.
627 #
628 # Key methods you need to implement:
629 # - __init__: Initialize the solver
630 # - sample: Main sampling function with your update rule
631 #
632 # Available helper methods from parent class:
633 # - self.get_text_embed(null_prompt, prompt): Get text embeddings
634 # - self.initialize_latent(): Initialize latent variable zT
635 # - self.predict_noise(zt, t, uc, c): Predict noise at timestep t
636 #
Tool Input
1{
2 "content": " def __init__(self,\n solver_config: Dict,\n model_key:str=\"runwayml/stable-diffusion-v1-5\",\n device: Optional[torch.device]=None,\n **kwargs):\n super().__init__(solver_config, model_key, device, **kwargs)\n\n @torch.autocast(device_type='cuda', dtype=torch.float16)\n def sample(self,\n cfg_guidance=1.0,\n prompt=[\"\",\"\"],\n callback_fn=None,\n **kwargs):\n \n t_fn = lambda sigma: sigma.log().neg()\n \n uc, c = self.get_text_embed(null_prompt=prompt[0], prompt=prompt[1])\n \n total_sigmas = (1-self.total_alphas).sqrt() / self.total_alphas.sqrt()\n sigmas = get_sigmas_karras(len(self.scheduler.timesteps), total_sigmas.min(), total_sigmas.max(), rho=7., device=self.device)\n \n x = self.initialize_latent(method=\"random_kdiffusion\",\n latent_dim=(1, 4, 64, 64),\n sigmas=sigmas).to(self.dtype)\n \n old_denoised = None\n \n pbar = tqdm(self.scheduler.timesteps, desc=\"DPM++2M-SDE Exact\")\n for i, _ in enumerate(pbar):\n sigma = sigmas[i]\n new_t = self.timestep(sigma).to(self.device)\n \n with torch.no_grad():\n denoised, _ = self.kdiffusion_x_to_denoised(x, sigma, uc, c, cfg_guidance, new_t)\n \n sigma_down, sigma_up = self.get_ancestral_step(sigmas[i], sigmas[i + 1], eta=1.0)\n \n if sigma_down == 0:\n d = self.to_d(x, sigmas[i], denoised)\n x = denoised + d * sigma_down\n else:\n t = t_fn(sigmas[i])\n t_next = t_fn(sigma_down)\n h = t_next - t\n \n h_f32 = h.float()\n I_0_f32 = -(-h_f32).expm1()\n I_1_f32 = h_f32 - I_0_f32\n \n I_0 = I_0_f32.to(h.dtype)\n I_1 = I_1_f32.to(h.dtype)\n \n if old_denoised is None:\n x = torch.exp(-h) * x + I_0 * denoised\n else:\n h_last = t - t_fn(sigmas[i-1])\n p_n = (denoised - old_denoised) / h_last\n x = torch.exp(-h) * x + I_0 * denoised + I_1 * p_n\n \n if sigmas[i + 1] > 0:\n x = x + torch.randn_like(x) * sigma_up\n \n old_denoised = denoised\n\n if callback_fn is not None:\n callback_kwargs = {'z0t': denoised.detach(),\n 'zt': x.detach(),\n 'decode': self.decode}\n callback_kwargs = callback_fn(i, new_t, callback_kwargs)\n denoised = callback_kwargs[\"z0t\"]\n x = callback_kwargs[\"zt\"]\n\n img = self.decode(x)\n img = (img / 2 + 0.5).clamp(0, 1)\n return img.detach().cpu()",
3 "end_line": 682,
4 "filename": "CFGpp-main/latent_diffusion.py",
5 "start_line": 624,
6 "op": "replace"
7}OK: Replaced lines 624..682 with 75 line(s) in CFGpp-main/latent_diffusion.py. Editable range: 624–698.
[Current file: CFGpp-main/latent_diffusion.py | editable: 624–698 | total: 1037 lines]
621| @register_solver("ddim_cfg++")
622| class BaseDDIMCFGpp(StableDiffusion):
623| # TODO: Implement your improved sampling method here.
624 def __init__(self,
625 solver_config: Dict,
626 model_key:str="runwayml/stable-diffusion-v1-5",
627 device: Optional[torch.device]=None,
628 **kwargs):
629 super().__init__(solver_config, model_key, device, **kwargs)
630
631 @torch.autocast(device_type='cuda', dtype=torch.float16)
632 def sample(self,
633 cfg_guidance=1.0,
634 prompt=["",""],
635 callback_fn=None,
636 **kwargs):
637
638 t_fn = lambda sigma: sigma.log().neg(
Tool Input
1{
2 "filename": "CFGpp-main/latent_sdxl.py",
3 "content": " def reverse_process(self,\n null_prompt_embeds,\n prompt_embeds,\n cfg_guidance,\n add_cond_kwargs,\n shape=(1024, 1024),\n callback_fn=None,\n **kwargs):\n \n t_fn = lambda sigma: sigma.log().neg()\n \n total_sigmas = (1-self.total_alphas).sqrt() / self.total_alphas.sqrt()\n sigmas = get_sigmas_karras(len(self.scheduler.timesteps), total_sigmas.min(), total_sigmas.max(), rho=7.).to(self.device)\n \n zt = self.initialize_latent(method=\"random_kdiffusion\",\n latent_dim=(1, 4, shape[0] // self.vae_scale_factor, shape[1] // self.vae_scale_factor),\n sigmas=sigmas).to(self.dtype)\n x = zt\n \n old_denoised = None\n\n pbar = tqdm(self.scheduler.timesteps, desc='SDXL-DPM++2M-SDE Exact')\n for i, _ in enumerate(pbar):\n sigma = sigmas[i]\n new_t = self.timestep(sigma).to(self.device)\n \n with torch.no_grad():\n denoised, _ = self.kdiffusion_zt_to_denoised(x, sigma, null_prompt_embeds, prompt_embeds, cfg_guidance, new_t, add_cond_kwargs)\n \n sigma_down, sigma_up = get_ancestral_step(sigmas[i], sigmas[i + 1], eta=1.0)\n \n if sigma_down == 0:\n d = self.to_d(x, sigmas[i], denoised)\n x = denoised + d * sigma_down\n else:\n t = t_fn(sigmas[i])\n t_next = t_fn(sigma_down)\n h = t_next - t\n \n h_f32 = h.float()\n I_0_f32 = -(-h_f32).expm1()\n I_1_f32 = h_f32 - I_0_f32\n \n I_0 = I_0_f32.to(h.dtype)\n I_1 = I_1_f32.to(h.dtype)\n \n if old_denoised is None:\n x = torch.exp(-h) * x + I_0 * denoised\n else:\n h_last = t - t_fn(sigmas[i-1])\n p_n = (denoised - old_denoised) / h_last\n x = torch.exp(-h) * x + I_0 * denoised + I_1 * p_n\n \n if sigmas[i + 1] > 0:\n x = x + torch.randn_like(x) * sigma_up\n \n old_denoised = denoised\n \n if callback_fn is not None:\n callback_kwargs = {'z0t': denoised.detach(),\n 'zt': x.detach(),\n 'decode': self.decode}\n callback_kwargs = callback_fn(i, new_t, callback_kwargs)\n denoised = callback_kwargs[\"z0t\"]\n x = callback_kwargs[\"zt\"]\n \n return x",
4 "start_line": 715,
5 "op": "replace",
6 "end_line": 749
7}OK: Replaced lines 715..749 with 67 line(s) in CFGpp-main/latent_sdxl.py. Editable range: 713–787.
[Current file: CFGpp-main/latent_sdxl.py | editable: 713–787 | total: 1063 lines]
710| # CFG++ version
711| ###########################################
712|
713 @register_solver("ddim_cfg++")
714 class BaseDDIMCFGpp(SDXL):
715 def reverse_process(self,
716 null_prompt_embeds,
717 prompt_embeds,
718 cfg_guidance,
719 add_cond_kwargs,
720 shape=(1024, 1024),
721 callback_fn=None,
722 **kwargs):
723
724 t_fn = lambda sigma: sigma.log().neg()
725
726 total_sigmas = (1-self.total_alphas).sqrt() / self.total_alphas.sqrt()
727 sigmas = get_sigmas_karras(len(self.scheduler.timesteps), total_sigmas.min(), total_sigmas
[Test #1] (2 tests remaining; call submit(n=1) to submit this result)
### sd15 (scripts/eval_sd15.sh)
Generation results:
GENERATION_METRICS model=sd15 method=ddim_cfg++ cfg_guidance=1.0 NFE=50 seed=42 fid=33.6476 clip_score=0.2742
sd15: CLIP=0.2742 FID=33.6476
Average CLIP score: 0.2742
Average FID: 33.6476
[Leaderboard] Results saved: {'clip_score_sd15': 0.2742, 'fid_sd15': 33.6476, 'clip_score': 0.2742, 'fid': 33.6476, 'elapsed_sd15': 969}Tool Input
1{
2 "content": " def __init__(self,\n solver_config: Dict,\n model_key:str=\"runwayml/stable-diffusion-v1-5\",\n device: Optional[torch.device]=None,\n **kwargs):\n super().__init__(solver_config, model_key, device, **kwargs)\n\n @torch.autocast(device_type='cuda', dtype=torch.float16)\n def sample(self,\n cfg_guidance=1.0,\n prompt=[\"\",\"\"],\n callback_fn=None,\n **kwargs):\n \n uc, c = self.get_text_embed(null_prompt=prompt[0], prompt=prompt[1])\n \n total_sigmas = (1-self.total_alphas).sqrt() / self.total_alphas.sqrt()\n sigmas = get_sigmas_karras(len(self.scheduler.timesteps), total_sigmas.min(), total_sigmas.max(), rho=7., device=self.device)\n \n x = self.initialize_latent(method=\"random_kdiffusion\",\n latent_dim=(1, 4, 64, 64),\n sigmas=sigmas).to(self.dtype)\n \n pbar = tqdm(self.scheduler.timesteps, desc=\"Euler Ancestral\")\n for i, _ in enumerate(pbar):\n sigma = sigmas[i]\n new_t = self.timestep(sigma).to(self.device)\n \n with torch.no_grad():\n denoised, _ = self.kdiffusion_x_to_denoised(x, sigma, uc, c, cfg_guidance, new_t)\n \n # Novel contribution: Noise Cutoff at the end\n progress = i / len(self.scheduler.timesteps)\n eta = 1.0 if progress < 0.9 else 0.0\n \n sigma_down, sigma_up = self.get_ancestral_step(sigmas[i], sigmas[i + 1], eta=eta)\n \n d = self.to_d(x, sigmas[i], denoised)\n x = denoised + d * sigma_down\n \n if sigmas[i + 1] > 0 and sigma_up > 0:\n x = x + torch.randn_like(x) * sigma_up\n\n if callback_fn is not None:\n callback_kwargs = {'z0t': denoised.detach(),\n 'zt': x.detach(),\n 'decode': self.decode}\n callback_kwargs = callback_fn(i, new_t, callback_kwargs)\n denoised = callback_kwargs[\"z0t\"]\n x = callback_kwargs[\"zt\"]\n\n img = self.decode(x)\n img = (img / 2 + 0.5).clamp(0, 1)\n return img.detach().cpu()",
3 "start_line": 624,
4 "op": "replace",
5 "end_line": 698,
6 "filename": "CFGpp-main/latent_diffusion.py"
7}OK: Replaced lines 624..698 with 54 line(s) in CFGpp-main/latent_diffusion.py. Editable range: 624–677.
[Current file: CFGpp-main/latent_diffusion.py | editable: 624–677 | total: 1016 lines]
621| @register_solver("ddim_cfg++")
622| class BaseDDIMCFGpp(StableDiffusion):
623| # TODO: Implement your improved sampling method here.
624 def __init__(self,
625 solver_config: Dict,
626 model_key:str="runwayml/stable-diffusion-v1-5",
627 device: Optional[torch.device]=None,
628 **kwargs):
629 super().__init__(solver_config, model_key, device, **kwargs)
630
631 @torch.autocast(device_type='cuda', dtype=torch.float16)
632 def sample(self,
633 cfg_guidance=1.0,
634 prompt=["",""],
635 callback_fn=None,
636 **kwargs):
637
638 uc, c = self.get_text_embed(null_prom
Tool Input
1{
2 "op": "replace",
3 "start_line": 715,
4 "content": " def reverse_process(self,\n null_prompt_embeds,\n prompt_embeds,\n cfg_guidance,\n add_cond_kwargs,\n shape=(1024, 1024),\n callback_fn=None,\n **kwargs):\n \n total_sigmas = (1-self.total_alphas).sqrt() / self.total_alphas.sqrt()\n sigmas = get_sigmas_karras(len(self.scheduler.timesteps), total_sigmas.min(), total_sigmas.max(), rho=7.).to(self.device)\n \n zt = self.initialize_latent(method=\"random_kdiffusion\",\n latent_dim=(1, 4, shape[0] // self.vae_scale_factor, shape[1] // self.vae_scale_factor),\n sigmas=sigmas).to(self.dtype)\n x = zt\n \n pbar = tqdm(self.scheduler.timesteps, desc='SDXL-Euler-Ancestral')\n for i, _ in enumerate(pbar):\n sigma = sigmas[i]\n new_t = self.timestep(sigma).to(self.device)\n \n with torch.no_grad():\n denoised, _ = self.kdiffusion_zt_to_denoised(x, sigma, null_prompt_embeds, prompt_embeds, cfg_guidance, new_t, add_cond_kwargs)\n \n # Noise cutoff trick\n progress = i / len(self.scheduler.timesteps)\n eta = 1.0 if progress < 0.9 else 0.0\n \n sigma_down, sigma_up = get_ancestral_step(sigmas[i], sigmas[i + 1], eta=eta)\n \n d = self.to_d(x, sigmas[i], denoised)\n x = denoised + d * sigma_down\n \n if sigmas[i + 1] > 0 and sigma_up > 0:\n x = x + torch.randn_like(x) * sigma_up\n \n if callback_fn is not None:\n callback_kwargs = {'z0t': denoised.detach(),\n 'zt': x.detach(),\n 'decode': self.decode}\n callback_kwargs = callback_fn(i, new_t, callback_kwargs)\n denoised = callback_kwargs[\"z0t\"]\n x = callback_kwargs[\"zt\"]\n \n return x",
5 "end_line": 781,
6 "filename": "CFGpp-main/latent_sdxl.py"
7}OK: Replaced lines 715..781 with 46 line(s) in CFGpp-main/latent_sdxl.py. Editable range: 713–766.
[Current file: CFGpp-main/latent_sdxl.py | editable: 713–766 | total: 1042 lines]
710| # CFG++ version
711| ###########################################
712|
713 @register_solver("ddim_cfg++")
714 class BaseDDIMCFGpp(SDXL):
715 def reverse_process(self,
716 null_prompt_embeds,
717 prompt_embeds,
718 cfg_guidance,
719 add_cond_kwargs,
720 shape=(1024, 1024),
721 callback_fn=None,
722 **kwargs):
723
724 total_sigmas = (1-self.total_alphas).sqrt() / self.total_alphas.sqrt()
725 sigmas = get_sigmas_karras(len(self.scheduler.timesteps), total_sigmas.min(), total_sigmas.max(), rho=7.).to(self.device)
726
727 zt = se
[Test #2] (1 test remaining; call submit(n=2) to submit this result)
### sd15 (scripts/eval_sd15.sh)
Generation results:
GENERATION_METRICS model=sd15 method=ddim_cfg++ cfg_guidance=1.0 NFE=50 seed=42 fid=34.3202 clip_score=0.2714
sd15: CLIP=0.2714 FID=34.3202
Average CLIP score: 0.2714
Average FID: 34.3202
[Leaderboard] Results saved: {'clip_score_sd15': 0.2714, 'fid_sd15': 34.3202, 'clip_score': 0.2714, 'fid': 34.3202, 'elapsed_sd15': 950}Tool Input
1{
2 "start_line": 624,
3 "end_line": 677,
4 "op": "replace",
5 "filename": "CFGpp-main/latent_diffusion.py",
6 "content": " def __init__(self,\n solver_config: Dict,\n model_key:str=\"runwayml/stable-diffusion-v1-5\",\n device: Optional[torch.device]=None,\n **kwargs):\n super().__init__(solver_config, model_key, device, **kwargs)\n\n @torch.autocast(device_type='cuda', dtype=torch.float16)\n def sample(self,\n cfg_guidance=1.0,\n prompt=[\"\",\"\"],\n callback_fn=None,\n **kwargs):\n \n t_fn = lambda sigma: sigma.log().neg()\n sigma_fn = lambda t: t.neg().exp()\n \n uc, c = self.get_text_embed(null_prompt=prompt[0], prompt=prompt[1])\n \n total_sigmas = (1-self.total_alphas).sqrt() / self.total_alphas.sqrt()\n \n num_steps = len(self.scheduler.timesteps) // 2\n sigmas = get_sigmas_karras(num_steps, total_sigmas.min(), total_sigmas.max(), rho=7., device=self.device)\n \n x = self.initialize_latent(method=\"random_kdiffusion\",\n latent_dim=(1, 4, 64, 64),\n sigmas=sigmas).to(self.dtype)\n \n pbar = tqdm(range(len(sigmas) - 1), desc=\"DPM++2S Ancestral + Eta Decay\")\n for i in pbar:\n sigma = sigmas[i]\n new_t = self.timestep(sigma).to(self.device)\n \n with torch.no_grad():\n denoised, _ = self.kdiffusion_x_to_denoised(x, sigma, uc, c, cfg_guidance, new_t)\n \n # Novel regularization: noise cutoff schedule\n progress = i / num_steps\n eta = 1.0 if progress < 0.8 else 0.0\n \n sigma_down, sigma_up = self.get_ancestral_step(sigmas[i], sigmas[i + 1], eta=eta)\n \n if sigma_down == 0:\n d = self.to_d(x, sigmas[i], denoised)\n x = denoised + d * sigma_down\n else:\n t = t_fn(sigmas[i])\n t_next = t_fn(sigma_down)\n r = 1 / 2\n h = t_next - t\n s = t + r * h\n \n h_f32 = h.float()\n h_r_f32 = (h_f32 * r)\n \n exp_h_r = torch.exp(-h_r_f32).to(h.dtype)\n I_0_r = -(-h_r_f32).expm1().to(h.dtype)\n \n x_2 = exp_h_r * x + I_0_r * denoised\n \n with torch.no_grad():\n sigma_s = sigma_fn(s)\n t_2 = self.timestep(sigma_s).to(self.device)\n denoised_2, _ = self.kdiffusion_x_to_denoised(x_2, sigma_s, uc, c, cfg_guidance, t_2)\n \n exp_h = torch.exp(-h_f32).to(h.dtype)\n I_0 = -(-h_f32).expm1().to(h.dtype)\n \n x = exp_h * x + I_0 * denoised_2\n \n if sigmas[i + 1] > 0 and sigma_up > 0:\n x = x + torch.randn_like(x) * sigma_up\n\n if callback_fn is not None:\n callback_kwargs = {'z0t': denoised.detach(),\n 'zt': x.detach(),\n 'decode': self.decode}\n callback_kwargs = callback_fn(i, new_t, callback_kwargs)\n denoised = callback_kwargs[\"z0t\"]\n x = callback_kwargs[\"zt\"]\n\n img = self.decode(x)\n img = (img / 2 + 0.5).clamp(0, 1)\n return img.detach().cpu()"
7}OK: Replaced lines 624..677 with 84 line(s) in CFGpp-main/latent_diffusion.py. Editable range: 624–707.
[Current file: CFGpp-main/latent_diffusion.py | editable: 624–707 | total: 1046 lines]
621| @register_solver("ddim_cfg++")
622| class BaseDDIMCFGpp(StableDiffusion):
623| # TODO: Implement your improved sampling method here.
624 def __init__(self,
625 solver_config: Dict,
626 model_key:str="runwayml/stable-diffusion-v1-5",
627 device: Optional[torch.device]=None,
628 **kwargs):
629 super().__init__(solver_config, model_key, device, **kwargs)
630
631 @torch.autocast(device_type='cuda', dtype=torch.float16)
632 def sample(self,
633 cfg_guidance=1.0,
634 prompt=["",""],
635 callback_fn=None,
636 **kwargs):
637
638 t_fn = lambda sigma: sigma.log().neg(
Tool Input
1{
2 "content": " def reverse_process(self,\n null_prompt_embeds,\n prompt_embeds,\n cfg_guidance,\n add_cond_kwargs,\n shape=(1024, 1024),\n callback_fn=None,\n **kwargs):\n \n t_fn = lambda sigma: sigma.log().neg()\n sigma_fn = lambda t: t.neg().exp()\n \n total_sigmas = (1-self.total_alphas).sqrt() / self.total_alphas.sqrt()\n num_steps = len(self.scheduler.timesteps) // 2\n sigmas = get_sigmas_karras(num_steps, total_sigmas.min(), total_sigmas.max(), rho=7.).to(self.device)\n \n zt = self.initialize_latent(method=\"random_kdiffusion\",\n latent_dim=(1, 4, shape[0] // self.vae_scale_factor, shape[1] // self.vae_scale_factor),\n sigmas=sigmas).to(self.dtype)\n x = zt\n \n pbar = tqdm(range(len(sigmas) - 1), desc='SDXL-DPM++2S Ancestral + Eta Decay')\n for i in pbar:\n sigma = sigmas[i]\n new_t = self.timestep(sigma).to(self.device)\n \n with torch.no_grad():\n denoised, _ = self.kdiffusion_zt_to_denoised(x, sigma, null_prompt_embeds, prompt_embeds, cfg_guidance, new_t, add_cond_kwargs)\n \n progress = i / num_steps\n eta = 1.0 if progress < 0.8 else 0.0\n \n sigma_down, sigma_up = get_ancestral_step(sigmas[i], sigmas[i + 1], eta=eta)\n \n if sigma_down == 0:\n d = self.to_d(x, sigmas[i], denoised)\n x = denoised + d * sigma_down\n else:\n t = t_fn(sigmas[i])\n t_next = t_fn(sigma_down)\n r = 1 / 2\n h = t_next - t\n s = t + r * h\n \n h_f32 = h.float()\n h_r_f32 = (h_f32 * r)\n \n exp_h_r = torch.exp(-h_r_f32).to(h.dtype)\n I_0_r = -(-h_r_f32).expm1().to(h.dtype)\n \n x_2 = exp_h_r * x + I_0_r * denoised\n \n with torch.no_grad():\n sigma_s = sigma_fn(s)\n t_2 = self.timestep(sigma_s).to(self.device)\n denoised_2, _ = self.kdiffusion_zt_to_denoised(x_2, sigma_s, null_prompt_embeds, prompt_embeds, cfg_guidance, t_2, add_cond_kwargs)\n \n exp_h = torch.exp(-h_f32).to(h.dtype)\n I_0 = -(-h_f32).expm1().to(h.dtype)\n \n x = exp_h * x + I_0 * denoised_2\n \n if sigmas[i + 1] > 0 and sigma_up > 0:\n x = x + torch.randn_like(x) * sigma_up\n \n if callback_fn is not None:\n callback_kwargs = {'z0t': denoised.detach(),\n 'zt': x.detach(),\n 'decode': self.decode}\n callback_kwargs = callback_fn(i, new_t, callback_kwargs)\n denoised = callback_kwargs[\"z0t\"]\n x = callback_kwargs[\"zt\"]\n \n return x",
3 "filename": "CFGpp-main/latent_sdxl.py",
4 "start_line": 715,
5 "end_line": 760,
6 "op": "replace"
7}OK: Replaced lines 715..760 with 74 line(s) in CFGpp-main/latent_sdxl.py. Editable range: 713–794.
[Current file: CFGpp-main/latent_sdxl.py | editable: 713–794 | total: 1070 lines]
710| # CFG++ version
711| ###########################################
712|
713 @register_solver("ddim_cfg++")
714 class BaseDDIMCFGpp(SDXL):
715 def reverse_process(self,
716 null_prompt_embeds,
717 prompt_embeds,
718 cfg_guidance,
719 add_cond_kwargs,
720 shape=(1024, 1024),
721 callback_fn=None,
722 **kwargs):
723
724 t_fn = lambda sigma: sigma.log().neg()
725 sigma_fn = lambda t: t.neg().exp()
726
727 total_sigmas = (1-self.total_alphas).sqrt() / self.total_alphas.sqrt()
728 num_steps = len(self.scheduler.timestep