Added ability to pair samples with a closer noise with optimal_noise_…

…pairing_samples

jobs/process/BaseSDTrainProcess.py

@@ -778,15 +778,37 @@ def get_sigmas(self, timesteps, n_dim=4, dtype=torch.float32):
         while len(sigma.shape) < n_dim:
             sigma = sigma.unsqueeze(-1)
         return sigma
+
+    def get_optimal_noise(self, latents, dtype=torch.float32):
+        batch_num = latents.shape[0]
+        chunks = torch.chunk(latents, batch_num, dim=0)
+        noise_chunks = []
+        for chunk in chunks:
+            noise_samples = [torch.randn_like(chunk, device=chunk.device, dtype=dtype) for _ in range(self.train_config.optimal_noise_pairing_samples)]
+            # find the one most similar to the chunk
+            lowest_loss = 999999999999
+            best_noise = None
+            for noise in noise_samples:
+                loss = torch.nn.functional.mse_loss(chunk, noise)
+                if loss < lowest_loss:
+                    lowest_loss = loss
+                    best_noise = noise
+            noise_chunks.append(best_noise)
+        noise = torch.cat(noise_chunks, dim=0)
+        return noise
+
 
     def get_noise(self, latents, batch_size, dtype=torch.float32):
-        # get noise
-        noise = self.sd.get_latent_noise(
-            height=latents.shape[2],
-            width=latents.shape[3],
-            batch_size=batch_size,
-            noise_offset=self.train_config.noise_offset,
-        ).to(self.device_torch, dtype=dtype)
+        if self.train_config.optimal_noise_pairing_samples > 1:
+            noise = self.get_optimal_noise(latents, dtype=dtype)
+        else:
+            # get noise
+            noise = self.sd.get_latent_noise(
+                height=latents.shape[2],
+                width=latents.shape[3],
+                batch_size=batch_size,
+                noise_offset=self.train_config.noise_offset,
+            ).to(self.device_torch, dtype=dtype)
 
         if self.train_config.random_noise_shift > 0.0:
             # get random noise -1 to 1

toolkit/config_modules.py

@@ -403,6 +403,9 @@ def __init__(self, **kwargs):
 
         # diffusion feature extractor
         self.diffusion_feature_extractor_path = kwargs.get('diffusion_feature_extractor_path', None)
+
+        # optimal noise pairing
+        self.optimal_noise_pairing_samples = kwargs.get('optimal_noise_pairing_samples', 1)
 
 
 class ModelConfig: