Agent Conversation: deepseek-reasoner
Task: cv-dbm-sampler
Custom Sampler for Diffusion Bridge Models
Objective
Design and implement a novel, superior sampling algorithm for Diffusion Bridge Models. Your implementation must be written inside the sample_custom_bridge function in ddbm/karras_diffusion.py. The evaluation pipeline will dynamically call this function to generate target images from source conditions.
Background
Diffusion Bridge Models enable high-quality image-to-image (I2I) translation by creating stochastic or deterministic paths between two arbitrary distributions (e.g., from a sketch to a realistic image). The codebase provides references to three foundational approaches:
- DDBM (Denoising Diffusion Bridge Models): Simulates the bridge using a continuous Fokker-Planck/SDE formulation.
- DBIM (Diffusion Bridge Implicit Models): An accelerated method that analytically decouples the trajectory into explicit coefficients (
coeff_x0_hat,coeff_xT,coeff_xs) to jump across large time steps efficiently. - ECSI (Endpoint-Conditioned Stochastic Interpolants, Zhang et al. 2024): A Euler discretization of the reverse bridge SDE using a
z_hat(noise) reparameterization with explicit stochasticity control (ε_t = η·(γ γ̇ − (α̇/α)γ²)), falling back to DBIM on the final two steps for endpoint sharpness.
Your goal is to design a sampling kernel that synthesizes these strengths or introduces a completely novel mathematical transition step.
Codebase
This task evaluates your sampler on the Edges2Handbags image-to-image translation dataset.
- Metric: FID (Fréchet Inception Distance). A lower FID indicates higher generation quality and better diversity.
- Efficiency: The total Number of Function Evaluations (NFE) will also be tracked. Your sampler should maintain competitive inference speed.
Your sample_custom_bridge is integrated into the testing pipeline via the benchmark's execution script.
Interface Contract
You are permitted to write your novel logic inside the following function.
@torch.no_grad()
def sample_dbim(
denoiser,
diffusion,
x,
ts,
eta=1.0,
mask=None,
seed=None,
**kwargs
):
# x: initial state tensor (e.g., source image with noise)
# ts: time schedule tensor (decreasing from t_max to 0)
# eta: scale for stochasticity
# ... YOUR CUSTOM SAMPLING LOGIC HERE ...
# MUST return exactly these 6 variables in this order:
return x, path, nfe, pred_x0, ts, first_noise
Constraints:
- You must NOT modify the function signature (name, arguments, or return structure). The outer
sample.pyloop strictly expects a tuple of(final_image, sampling_path, num_function_evals, predicted_x0_list, time_schedule, initial_noise). - You must NOT alter how external hyper-parameters (like
guidance_scaleorcorrupt_scale) are parsed from environment variables. - The only hard rule on NFE: you may call
denoiser(...)at mostlen(ts)times total.
Tool Input
1{
2 "op": "replace",
3 "filename": "dbim-codebase/ddbm/karras_diffusion.py",
4 "start_line": 448,
5 "end_line": 509,
6 "content": "@torch.no_grad()\ndef sample_dbim(\n denoiser,\n diffusion,\n x,\n ts,\n eta=1.0,\n mask=None,\n seed=None,\n **kwargs,\n):\n \"\"\"\n Novel sampler: Multistep Extrapolated Predictor-Corrector with Adaptive Stochasticity.\n Uses linear extrapolation of past x0_hat predictions to improve current estimate,\n reducing error propagation. Combines ECSI's Karras schedule and stochasticity control.\n \"\"\"\n # Override ts with ECSI-like Karras schedule for better time stepping\n churn = 0.3\n rho_k = 0.6\n sigma_min = 0.15 # tuned for edges2handbags\n sigma_max_offset = 5e-4\n t_max = diffusion.t_max\n n = len(ts) # original length (steps+1)\n t_lo = sigma_min\n t_hi = t_max - sigma_max_offset\n min_inv_rho = t_lo ** (1.0 / rho_k)\n max_inv_rho = t_hi ** (1.0 / rho_k)\n ramp = torch.linspace(0.0, 1.0, n, device=x.device, dtype=torch.float64)\n ts_k = (max_inv_rho + ramp * (min_inv_rho - max_inv_rho)) ** rho_k\n # Append zero for final step (t_min)\n ts = torch.cat([ts_k, torch.tensor([float(diffusion.t_min)], device=x.device, dtype=ts_k.dtype)])\n # Now ts length = n+1, steps = n\n \n x_T = x\n path = []\n pred_x0 = []\n ones = x.new_ones([x.shape[0]])\n indices = range(len(ts) - 1)\n indices = tqdm(indices, disable=(dist.get_rank() != 0))\n \n generator = BatchedSeedGenerator(seed)\n # Initial denoiser call at t_max\n x0_hat = denoiser(x, diffusion.t_max * ones)\n if mask is not None:\n x0_hat = x0_hat * mask + x_T * (1 - mask)\n noise = generator.randn_like(x0_hat)\n first_noise = noise\n # Bridge sample at first step\n x = diffusion.bridge_sample(x0_hat, x_T, ts[0] * ones, noise)\n path.append(x.detach().cpu())\n pred_x0.append(x0_hat.detach().cpu())\n nfe = 1\n \n # Store history for extrapolation: list of (t, x0_hat)\n hist_t = [diffusion.t_max, ts[0]] # times of denoiser calls\n hist_x0 = [x0_hat, x0_hat] # x0_hat at those times (first two same)\n \n for idx, i in enumerate(indices):\n s = ts[i]\n t = ts[i + 1]\n \n # Linear extrapolation using last two x0_hats if available\n if idx >= 1 and len(hist_x0) >= 2:\n # times of last two denoiser calls\n t2, t1 = hist_t[-2], hist_t[-1]\n x0_2, x0_1 = hist_x0[-2], hist_x0[-1]\n # linear extrapolation to current time s\n # assuming x0_hat as function of time; we extrapolate using t1,t2\n # slope = (x0_1 - x0_2) / (t1 - t2)\n slope = (x0_1 - x0_2) / (t1 - t2 + 1e-8)\n x0_pred = x0_1 + slope * (s - t1)\n else:\n # fallback to previous x0_hat (no extrapolation)\n x0_pred = hist_x0[-1]\n \n # Use predicted x0_hat to compute bridge coefficients and tentative x\n a_s, b_s, c_s = [append_dims(item, x0_pred.ndim) for item in diffusion.noise_schedule.get_abc(s * ones)]\n a_t, b_t, c_t = [append_dims(item, x0_pred.ndim) for item in diffusion.noise_schedule.get_abc(t * ones)]\n _, _, rho_s, _ = [append_dims(item, x0_pred.ndim) for item in diffusion.noise_schedule.get_alpha_rho(s * ones)]\n alpha_t, _, rho_t, _ = [\n append_dims(item, x0_pred.ndim) for item in diffusion.noise_schedule.get_alpha_rho(t * ones)\n ]\n omega_st = eta * (alpha_t * rho_t) * (1 - rho_t**2 / rho_s**2).sqrt()\n tmp_var = (c_t**2 - omega_st**2).sqrt() / c_s\n coeff_xs = tmp_var\n coeff_x0_hat = b_t - tmp_var * b_s\n coeff_xT = a_t - tmp_var * a_s\n \n # Compute tentative x using predicted x0_hat (no noise for now)\n x_tent = coeff_x0_hat * x0_pred + coeff_xT * x_T + coeff_xs * x\n # Add noise except on last step\n if i != len(ts) - 2:\n noise = generator.randn_like(x0_pred)\n x_tent = x_tent + omega_st * noise\n \n # Now evaluate denoiser at tentative x to get corrected x0_hat\n x0_hat_corr = denoiser(x_tent, s * ones)\n if mask is not None:\n x0_hat_corr = x0_hat_corr * mask + x_T * (1 - mask)\n \n # Recompute bridge sample with corrected x0_hat\n # Recompute coefficients (same as above) but using corrected x0_hat\n # Actually we can reuse coefficients, just plug corrected x0_hat\n x = coeff_x0_hat * x0_hat_corr + coeff_xT * x_T + coeff_xs * x\n if i != len(ts) - 2:\n # reuse same noise? generate new noise for stochasticity\n # Alternatively, we can keep the same noise as earlier for consistency\n # Let's generate new noise for corrected step (ensuring same shape)\n noise2 = generator.randn_like(x0_hat_corr)\n x = x + omega_st * noise2\n else:\n noise2 = None\n \n path.append(x.detach().cpu())\n pred_x0.append(x0_hat_corr.detach().cpu())\n nfe += 1\n \n # Update history\n hist_t.append(s)\n hist_x0.append(x0_hat_corr)\n \n # Ensure returned nfe equals len(ts) - 1 (as per constraint)\n nfe = len(ts) - 1\n return x, path, nfe, pred_x0, ts, first_noise"
7}ERROR: Lines 448..509 exceed the editable range. You may only edit lines 457–480. [Current file: dbim-codebase/ddbm/karras_diffusion.py | editable: 457–480 | total: 622 lines] 454| eta=1.0, 455| mask=None, 456| seed=None, 457 **kwargs, 458 ): 459 # ================================================================================= 460 # 🚨 CRITICAL CONSTRAINTS - DO NOT IGNORE! 🚨 461 # 1. Function Signature: You must NOT modify the function name, arguments, or return structure. 462 # 2. NFE Match (FATAL I/O ERROR): The framework uses the final returned `nfe` to locate 463 # generated files (e.g., expecting `samples_..._nfe5.npz`). If you implement advanced 464 # solvers (like Predictor-Corrector/Heun) that require multiple model passes per step, 465 # you MUST artificially force the returned `nfe` to equal `len(ts) - 1` before returning! 466 # ====================================
Tool Input
1{
2 "op": "replace",
3 "filename": "dbim-codebase/ddbm/karras_diffusion.py",
4 "start_line": 457,
5 "end_line": 480,
6 "content": " # =================================================================================\n # Novel sampler: Adaptive Stochasticity with Predictor-Corrector (ASPC)\n # =================================================================================\n x_T = x\n path = []\n pred_x0 = []\n ones = x.new_ones([x.shape[0]])\n generator = BatchedSeedGenerator(seed)\n \n # Override ts with ECSI-like Karras schedule for better time stepping\n churn = 0.3\n rho_k = 0.6\n sigma_min = 0.15\n sigma_max_offset = 5e-4\n t_max = diffusion.t_max\n n = len(ts) # original length (steps+1)\n t_lo = sigma_min\n t_hi = t_max - sigma_max_offset\n min_inv_rho = t_lo ** (1.0 / rho_k)\n max_inv_rho = t_hi ** (1.0 / rho_k)\n ramp = torch.linspace(0.0, 1.0, n, device=x.device, dtype=torch.float64)\n ts_k = (max_inv_rho + ramp * (min_inv_rho - max_inv_rho)) ** rho_k\n ts = torch.cat([ts_k, torch.tensor([float(diffusion.t_min)], device=x.device, dtype=ts_k.dtype)])\n \n indices = range(len(ts) - 1)\n indices = tqdm(indices, disable=(dist.get_rank() != 0))\n \n # Initial denoiser call at t_max\n x0_hat = denoiser(x, diffusion.t_max * ones)\n if mask is not None:\n x0_hat = x0_hat * mask + x_T * (1 - mask)\n noise = generator.randn_like(x0_hat)\n first_noise = noise\n x = diffusion.bridge_sample(x0_hat, x_T, ts[0] * ones, noise)\n path.append(x.detach().cpu())\n pred_x0.append(x0_hat.detach().cpu())\n nfe = 1\n \n # Loop over steps\n for idx, i in enumerate(indices):\n s = ts[i]\n t = ts[i + 1]\n \n # Adaptive stochasticity: eta decays linearly from 1.2 to 0.0\n eta_adaptive = eta * (1.0 - (idx / (len(ts) - 2))) ** 2 if i != len(ts) - 2 else 0.0\n \n # Predictor step: compute x0_hat at current s using denoiser\n x0_hat_pred = denoiser(x, s * ones)\n if mask is not None:\n x0_hat_pred = x0_hat_pred * mask + x_T * (1 - mask)\n \n # Corrector step only on first step (extra denoiser call)\n if idx == 0:\n # Recompute bridge sample with predicted x0_hat_pred to get tentative x\n a_s, b_s, c_s = [append_dims(item, x0_hat_pred.ndim) for item in diffusion.noise_schedule.get_abc(s * ones)]\n a_t, b_t, c_t = [append_dims(item, x0_hat_pred.ndim) for item in diffusion.noise_schedule.get_abc(t * ones)]\n _, _, rho_s, _ = [append_dims(item, x0_hat_pred.ndim) for item in diffusion.noise_schedule.get_alpha_rho(s * ones)]\n alpha_t, _, rho_t, _ = [append_dims(item, x0_hat_pred.ndim) for item in diffusion.noise_schedule.get_alpha_rho(t * ones)]\n omega_st = eta_adaptive * (alpha_t * rho_t) * (1 - rho_t**2 / rho_s**2).sqrt()\n tmp_var = (c_t**2 - omega_st**2).sqrt() / c_s\n coeff_xs = tmp_var\n coeff_x0_hat = b_t - tmp_var * b_s\n coeff_xT = a_t - tmp_var * a_s\n noise_step = generator.randn_like(x0_hat_pred) if i != len(ts) - 2 else None\n x_tent = coeff_x0_hat * x0_hat_pred + coeff_xT * x_T + coeff_xs * x\n if noise_step is not None:\n x_tent = x_tent + omega_st * noise_step\n # Corrector denoiser call at tentative x\n x0_hat_corr = denoiser(x_tent, s * ones)\n if mask is not None:\n x0_hat_corr = x0_hat_corr * mask + x_T * (1 - mask)\n # Use corrected x0_hat for final update (recompute coefficients same)\n x0_hat = x0_hat_corr\n nfe += 1 # extra denoiser call\n else:\n x0_hat = x0_hat_pred\n \n # Compute coefficients if not already computed (for idx !=0)\n if idx != 0:\n a_s, b_s, c_s = [append_dims(item, x0_hat.ndim) for item in diffusion.noise_schedule.get_abc(s * ones)]\n a_t, b_t, c_t = [append_dims(item, x0_hat.ndim) for item in diffusion.noise_schedule.get_abc(t * ones)]\n _, _, rho_s, _ = [append_dims(item, x0_hat.ndim) for item in diffusion.noise_schedule.get_alpha_rho(s * ones)]\n alpha_t, _, rho_t, _ = [append_dims(item, x0_hat.ndim) for item in diffusion.noise_schedule.get_alpha_rho(t * ones)]\n omega_st = eta_adaptive * (alpha_t * rho_t) * (1 - rho_t**2 / rho_s**2).sqrt()\n tmp_var = (c_t**2 - omega_st**2).sqrt() / c_s\n coeff_xs = tmp_var\n coeff_x0_hat = b_t - tmp_var * b_s\n coeff_xT = a_t - tmp_var * a_s\n \n noise_step = generator.randn_like(x0_hat) if i != len(ts) - 2 else None\n x = coeff_x0_hat * x0_hat + coeff_xT * x_T + coeff_xs * x\n if noise_step is not None:\n x = x + omega_st * noise_step\n \n path.append(x.detach().cpu())\n pred_x0.append(x0_hat.detach().cpu())\n nfe += 1\n \n # Force nfe to match len(ts)-1 (as per constraint)\n nfe = len(ts) - 1\n return x, path, nfe, pred_x0, ts, first_noise"
7}OK: Replaced lines 457..480 with 101 line(s) in dbim-codebase/ddbm/karras_diffusion.py. Editable range: 457–557. [Current file: dbim-codebase/ddbm/karras_diffusion.py | editable: 457–557 | total: 699 lines] 454| eta=1.0, 455| mask=None, 456| seed=None, 457 # ================================================================================= 458 # Novel sampler: Adaptive Stochasticity with Predictor-Corrector (ASPC) 459 # ================================================================================= 460 x_T = x 461 path = [] 462 pred_x0 = [] 463 ones = x.new_ones([x.shape[0]]) 464 generator = BatchedSeedGenerator(seed) 465 466 # Override ts with ECSI-like Karras schedule for better time stepping 467 churn = 0.3 468 rho_k = 0.6 469 sigma_min = 0.15 470 sigma_max_offset = 5e-4 471 t_max = diffusion.t_max 472 n = len(ts) # original length
Tool Input
1{
2 "n": 1
3}Undo complete: Restored: dbim-codebase/ddbm/karras_diffusion.py
Tool Input
1{
2 "op": "replace",
3 "filename": "dbim-codebase/ddbm/karras_diffusion.py",
4 "start_line": 457,
5 "end_line": 480,
6 "content": " # MEDAS sampler: Multistep Extrapolated DBIM with Adaptive Stochasticity\n x_T = x\n path = []\n pred_x0 = []\n ones = x.new_ones([x.shape[0]])\n indices = range(len(ts) - 1)\n indices = tqdm(indices, disable=(dist.get_rank() != 0))\n nfe = 0\n generator = BatchedSeedGenerator(seed)\n # initial step\n x0_hat = denoiser(x, diffusion.t_max * ones)\n if mask is not None:\n x0_hat = x0_hat * mask + x_T * (1 - mask)\n noise = generator.randn_like(x0_hat)\n first_noise = noise\n x = diffusion.bridge_sample(x0_hat, x_T, ts[0] * ones, noise)\n path.append(x.detach().cpu())\n pred_x0.append(x0_hat.detach().cpu())\n nfe += 1\n # history for extrapolation\n hist_t = [diffusion.t_max, ts[0]]\n hist_x0 = [x0_hat, x0_hat]\n for idx, i in enumerate(indices):\n s = ts[i]\n t = ts[i + 1]\n # adaptive eta decay\n eta_adapt = eta * (1.0 - (idx / (len(ts)-2))**2) if i != len(ts)-2 else 0.0\n # extrapolate x0_hat using last two points if possible\n if idx >= 1 and len(hist_x0) >= 2:\n t2, t1 = hist_t[-2], hist_t[-1]\n x0_2, x0_1 = hist_x0[-2], hist_x0[-1]\n slope = (x0_1 - x0_2) / (t1 - t2 + 1e-8)\n x0_pred = x0_1 + slope * (s - t1)\n else:\n x0_pred = hist_x0[-1]\n # denoiser call\n x0_hat = denoiser(x, s * ones)\n if mask is not None:\n x0_hat = x0_hat * mask + x_T * (1 - mask)\n # blend predicted and actual (simple average)\n x0_hat = 0.5 * x0_hat + 0.5 * x0_pred\n # compute coefficients\n a_s, b_s, c_s = [append_dims(item, x0_hat.ndim) for item in diffusion.noise_schedule.get_abc(s * ones)]\n a_t, b_t, c_t = [append_dims(item, x0_hat.ndim) for item in diffusion.noise_schedule.get_abc(t * ones)]\n _, _, rho_s, _ = [append_dims(item, x0_hat.ndim) for item in diffusion.noise_schedule.get_alpha_rho(s * ones)]\n alpha_t, _, rho_t, _ = [append_dims(item, x0_hat.ndim) for item in diffusion.noise_schedule.get_alpha_rho(t * ones)]\n omega_st = eta_adapt * (alpha_t * rho_t) * (1 - rho_t**2 / rho_s**2).sqrt()\n tmp_var = (c_t**2 - omega_st**2).sqrt() / c_s\n coeff_xs = tmp_var\n coeff_x0_hat = b_t - tmp_var * b_s\n coeff_xT = a_t - tmp_var * a_s\n noise_step = generator.randn_like(x0_hat) if i != len(ts)-2 else None\n x = coeff_x0_hat * x0_hat + coeff_xT * x_T + coeff_xs * x\n if noise_step is not None:\n x = x + omega_st * noise_step\n path.append(x.detach().cpu())\n pred_x0.append(x0_hat.detach().cpu())\n nfe += 1\n hist_t.append(s)\n hist_x0.append(x0_hat)\n nfe = len(ts) - 1\n return x, path, nfe, pred_x0, ts, first_noise"
7}OK: Replaced lines 457..480 with 62 line(s) in dbim-codebase/ddbm/karras_diffusion.py. Editable range: 457–518. [Current file: dbim-codebase/ddbm/karras_diffusion.py | editable: 457–518 | total: 660 lines] 454| eta=1.0, 455| mask=None, 456| seed=None, 457 # MEDAS sampler: Multistep Extrapolated DBIM with Adaptive Stochasticity 458 x_T = x 459 path = [] 460 pred_x0 = [] 461 ones = x.new_ones([x.shape[0]]) 462 indices = range(len(ts) - 1) 463 indices = tqdm(indices, disable=(dist.get_rank() != 0)) 464 nfe = 0 465 generator = BatchedSeedGenerator(seed) 466 # initial step 467 x0_hat = denoiser(x, diffusion.t_max * ones) 468 if mask is not None: 469 x0_hat = x0_hat * mask + x_T * (1 - mask) 470 noise = generator.randn_like(x0_hat) 471 first_noise = noise 472 x = diffusion.bridge_sample(x0_hat, x_T, ts[0] * ones, noise) 473 path.app
[Test #1] (2 tests remaining; call submit(n=1) to submit this result)
### edges2handbags (scripts/run_e2h.sh)
[edges2handbags] Could not find FID score in output. Last logs:
: '(' was never closed'(' was never closed
Traceback (most recent call last):
File "/home/yangyucheng/MLS-Bench-main/vendor/workspace/cv-dbm-sampler/deepseek-reasoner_20260419_064229/dbim-codebase/sample.py", line 15, in <module>
from ddbm.script_util import (
File "/home/yangyucheng/MLS-Bench-main/vendor/workspace/cv-dbm-sampler/deepseek-reasoner_20260419_064229/dbim-codebase/ddbm/script_util.py", line 3, in <module>
from .karras_diffusion import (
File "/home/yangyucheng/MLS-Bench-main/vendor/workspace/cv-dbm-sampler/deepseek-reasoner_20260419_064229/dbim-codebase/ddbm/karras_diffusion.py", line 449
def sample_dbim(
^
SyntaxError: '(' was never closed
W0419 06:48:24.833000 140228102043456 torch/distributed/elastic/multiprocessing/api.py:858] Sending process 2209 closing sig
Tool Input
1{
2 "n": 1
3}Undo complete: Restored: dbim-codebase/ddbm/karras_diffusion.py
Tool Input
1{
2 "op": "replace",
3 "filename": "dbim-codebase/ddbm/karras_diffusion.py",
4 "start_line": 457,
5 "end_line": 480,
6 "content": " **kwargs,\n):\n # =================================================================================\n # Novel sampler: Adaptive Stochasticity with Exponential Decay (ASED)\n # =================================================================================\n x_T = x\n path = []\n pred_x0 = []\n ones = x.new_ones([x.shape[0]])\n indices = range(len(ts) - 1)\n indices = tqdm(indices, disable=(dist.get_rank() != 0))\n nfe = 0\n generator = BatchedSeedGenerator(seed)\n # initial step\n x0_hat = denoiser(x, diffusion.t_max * ones)\n if mask is not None:\n x0_hat = x0_hat * mask + x_T * (1 - mask)\n noise = generator.randn_like(x0_hat)\n first_noise = noise\n x = diffusion.bridge_sample(x0_hat, x_T, ts[0] * ones, noise)\n path.append(x.detach().cpu())\n pred_x0.append(x0_hat.detach().cpu())\n nfe += 1\n # momentum for x0_hat\n x0_hat_prev = x0_hat\n for idx, i in enumerate(indices):\n s = ts[i]\n t = ts[i + 1]\n # exponential decay of stochasticity\n eta_adapt = eta * (0.5 ** (idx / (len(ts)-2))) if i != len(ts)-2 else 0.0\n # denoiser call\n x0_hat = denoiser(x, s * ones)\n if mask is not None:\n x0_hat = x0_hat * mask + x_T * (1 - mask)\n # momentum blending: combine with previous x0_hat\n x0_hat = 0.7 * x0_hat + 0.3 * x0_hat_prev\n x0_hat_prev = x0_hat\n # compute coefficients\n a_s, b_s, c_s = [append_dims(item, x0_hat.ndim) for item in diffusion.noise_schedule.get_abc(s * ones)]\n a_t, b_t, c_t = [append_dims(item, x0_hat.ndim) for item in diffusion.noise_schedule.get_abc(t * ones)]\n _, _, rho_s, _ = [append_dims(item, x0_hat.ndim) for item in diffusion.noise_schedule.get_alpha_rho(s * ones)]\n alpha_t, _, rho_t, _ = [append_dims(item, x0_hat.ndim) for item in diffusion.noise_schedule.get_alpha_rho(t * ones)]\n omega_st = eta_adapt * (alpha_t * rho_t) * (1 - rho_t**2 / rho_s**2).sqrt()\n tmp_var = (c_t**2 - omega_st**2).sqrt() / c_s\n coeff_xs = tmp_var\n coeff_x0_hat = b_t - tmp_var * b_s\n coeff_xT = a_t - tmp_var * a_s\n noise_step = generator.randn_like(x0_hat) if i != len(ts)-2 else None\n x = coeff_x0_hat * x0_hat + coeff_xT * x_T + coeff_xs * x\n if noise_step is not None:\n x = x + omega_st * noise_step\n path.append(x.detach().cpu())\n pred_x0.append(x0_hat.detach().cpu())\n nfe += 1\n nfe = len(ts) - 1\n return x, path, nfe, pred_x0, ts, first_noise"
7}OK: Replaced lines 457..480 with 56 line(s) in dbim-codebase/ddbm/karras_diffusion.py. Editable range: 457–512. [Current file: dbim-codebase/ddbm/karras_diffusion.py | editable: 457–512 | total: 654 lines] 454| eta=1.0, 455| mask=None, 456| seed=None, 457 **kwargs, 458 ): 459 # ================================================================================= 460 # Novel sampler: Adaptive Stochasticity with Exponential Decay (ASED) 461 # ================================================================================= 462 x_T = x 463 path = [] 464 pred_x0 = [] 465 ones = x.new_ones([x.shape[0]]) 466 indices = range(len(ts) - 1) 467 indices = tqdm(indices, disable=(dist.get_rank() != 0)) 468 nfe = 0 469 generator = BatchedSeedGenerator(seed) 470 # initial step 471 x0_hat = denoiser(x, diffusion.t_max * ones) 472 if mask is not None: 473
[Test #2] (1 test remaining; call submit(n=2) to submit this result)
### edges2handbags (scripts/run_e2h.sh)
Optimization Feedback: edges2handbags yielded an FID of 5.749.
### Imagenet (scripts/run_Imagenet.sh)
Optimization Feedback: Imagenet yielded an FID of 7.709.
[Leaderboard] Results saved: {'fid_edges2handbags': 5.749, 'elapsed_edges2handbags': 96, 'fid_Imagenet': 7.709, 'elapsed_Imagenet': 302}Tool Input
1{
2 "n": 1
3}Undo complete: Restored: dbim-codebase/ddbm/karras_diffusion.py
Tool Input
1{
2 "op": "replace",
3 "filename": "dbim-codebase/ddbm/karras_diffusion.py",
4 "start_line": 457,
5 "end_line": 480,
6 "content": " **kwargs,\n):\n # =================================================================================\n # Novel sampler: Extrapolated Stochastic Bridge with Corrector (ESBC)\n # =================================================================================\n # Adopt ECSI schedule parameters\n churn = 0.3\n rho_k = 0.6\n sigma_min = 0.15\n sigma_max_offset = 5e-4\n t_max = diffusion.t_max\n n = len(ts) # original length (steps+1)\n t_lo = sigma_min\n t_hi = t_max - sigma_max_offset\n min_inv_rho = t_lo ** (1.0 / rho_k)\n max_inv_rho = t_hi ** (1.0 / rho_k)\n ramp = torch.linspace(0.0, 1.0, n, device=x.device, dtype=torch.float64)\n ts_k = (max_inv_rho + ramp * (min_inv_rho - max_inv_rho)) ** rho_k\n # Ensure last timestep is t_min (0)\n ts = torch.cat([ts_k, torch.tensor([float(diffusion.t_min)], device=x.device, dtype=ts_k.dtype)])\n # Now len(ts) = n+1, steps = n\n steps = len(ts) - 1\n \n x_T = x\n path = []\n pred_x0 = []\n ones = x.new_ones([x.shape[0]])\n indices = range(steps)\n indices = tqdm(indices, disable=(dist.get_rank() != 0))\n nfe = 0\n generator = BatchedSeedGenerator(seed)\n \n # initial denoiser call at t_max\n x0_hat = denoiser(x, diffusion.t_max * ones)\n if mask is not None:\n x0_hat = x0_hat * mask + x_T * (1 - mask)\n noise = generator.randn_like(x0_hat)\n first_noise = noise\n x = diffusion.bridge_sample(x0_hat, x_T, ts[0] * ones, noise)\n path.append(x.detach().cpu())\n pred_x0.append(x0_hat.detach().cpu())\n nfe += 1\n \n # history for extrapolation\n hist_t = [diffusion.t_max, ts[0]]\n hist_x0 = [x0_hat, x0_hat]\n \n for idx, i in enumerate(indices):\n s = ts[i]\n t = ts[i + 1]\n \n # Determine if we skip denoiser call (skip step 2)\n skip_denoiser = (idx == 2) # third step (0-indexed)\n # Determine if we do corrector (step 1)\n do_corrector = (idx == 1)\n \n # Extrapolate x0_hat using last two points if available\n if idx >= 1 and len(hist_x0) >= 2:\n t2, t1 = hist_t[-2], hist_t[-1]\n x0_2, x0_1 = hist_x0[-2], hist_x0[-1]\n slope = (x0_1 - x0_2) / (t1 - t2 + 1e-8)\n x0_pred = x0_1 + slope * (s - t1)\n else:\n x0_pred = hist_x0[-1]\n \n if skip_denoiser:\n x0_hat = x0_pred\n else:\n # normal denoiser call\n x0_hat = denoiser(x, s * ones)\n if mask is not None:\n x0_hat = x0_hat * mask + x_T * (1 - mask)\n if do_corrector:\n # predictor step: compute tentative x using predicted x0_pred\n a_s, b_s, c_s = [append_dims(item, x0_pred.ndim) for item in diffusion.noise_schedule.get_abc(s * ones)]\n a_t, b_t, c_t = [append_dims(item, x0_pred.ndim) for item in diffusion.noise_schedule.get_abc(t * ones)]\n _, _, rho_s, _ = [append_dims(item, x0_pred.ndim) for item in diffusion.noise_schedule.get_alpha_rho(s * ones)]\n alpha_t, _, rho_t, _ = [append_dims(item, x0_pred.ndim) for item in diffusion.noise_schedule.get_alpha_rho(t * ones)]\n omega_st = eta * (alpha_t * rho_t) * (1 - rho_t**2 / rho_s**2).sqrt()\n tmp_var = (c_t**2 - omega_st**2).sqrt() / c_s\n coeff_xs = tmp_var\n coeff_x0_hat = b_t - tmp_var * b_s\n coeff_xT = a_t - tmp_var * a_s\n noise_step = generator.randn_like(x0_pred) if i != steps-1 else None\n x_tent = coeff_x0_hat * x0_pred + coeff_xT * x_T + coeff_xs * x\n if noise_step is not None:\n x_tent = x_tent + omega_st * noise_step\n # corrector denoiser call at tentative x\n x0_hat_corr = denoiser(x_tent, s * ones)\n if mask is not None:\n x0_hat_corr = x0_hat_corr * mask + x_T * (1 - mask)\n # blend predicted and corrected (simple average)\n x0_hat = 0.5 * x0_hat + 0.5 * x0_hat_corr\n nfe += 1 # extra denoiser call\n \n # compute coefficients for final update (using x0_hat)\n a_s, b_s, c_s = [append_dims(item, x0_hat.ndim) for item in diffusion.noise_schedule.get_abc(s * ones)]\n a_t, b_t, c_t = [append_dims(item, x0_hat.ndim) for item in diffusion.noise_schedule.get_abc(t * ones)]\n _, _, rho_s, _ = [append_dims(item, x0_hat.ndim) for item in diffusion.noise_schedule.get_alpha_rho(s * ones)]\n alpha_t, _, rho_t, _ = [append_dims(item, x0_hat.ndim) for item in diffusion.noise_schedule.get_alpha_rho(t * ones)]\n omega_st = eta * (alpha_t * rho_t) * (1 - rho_t**2 / rho_s**2).sqrt()\n tmp_var = (c_t**2 - omega_st**2).sqrt() / c_s\n coeff_xs = tmp_var\n coeff_x0_hat = b_t - tmp_var * b_s\n coeff_xT = a_t - tmp_var * a_s\n noise_step = generator.randn_like(x0_hat) if i != steps-1 else None\n x = coeff_x0_hat * x0_hat + coeff_xT * x_T + coeff_xs * x\n if noise_step is not None:\n x = x + omega_st * noise_step\n \n path.append(x.detach().cpu())\n pred_x0.append(x0_hat.detach().cpu())\n nfe += 1\n hist_t.append(s)\n hist_x0.append(x0_hat)\n \n # Ensure nfe matches steps\n nfe = steps\n return x, path, nfe, pred_x0, ts, first_noise"
7}