diff --git a/codes/models/diffusion/rrdb_diffusion.py b/codes/models/diffusion/rrdb_diffusion.py
index 0cbbe8ab..9deab2f3 100644
--- a/codes/models/diffusion/rrdb_diffusion.py
+++ b/codes/models/diffusion/rrdb_diffusion.py
@@ -173,13 +173,19 @@ class RRDBNet(nn.Module):
                 default_init_weights(m, 1.0)
         default_init_weights(self.conv_last, 0)
 
-    def forward(self, x, timesteps, low_res=None):
+    def forward(self, x, timesteps, low_res, correction_factors=None):
         emb = self.time_embed(timestep_embedding(timesteps, self.mid_channels))
 
         _, _, new_height, new_width = x.shape
         upsampled = F.interpolate(low_res, (new_height, new_width), mode="bilinear")
         x = torch.cat([x, upsampled], dim=1)
 
+        if correction_factors is not None:
+            correction_factors = correction_factors.view(x.shape[0], -1, 1, 1).repeat(1, 1, new_height, new_width)
+        else:
+            correction_factors = torch.zeros((b, self.num_corruptions, new_height, new_width), dtype=torch.float, device=x.device)
+        x = torch.cat([x, correction_factors], dim=1)
+
         d1 = self.input_block(x)
         d2 = self.down1(d1)
         feat = self.down2(d2)
diff --git a/codes/scripts/diffusion/diffusion_correction_surfer.py b/codes/scripts/diffusion/diffusion_correction_surfer.py
index 05eb25ce..0a319ba0 100644
--- a/codes/scripts/diffusion/diffusion_correction_surfer.py
+++ b/codes/scripts/diffusion/diffusion_correction_surfer.py
@@ -76,7 +76,7 @@ if __name__ == "__main__":
         im = im[:,dh:-dh]
     if dw > 0:
         im = im[:,:,dw:-dw]
-    im = im.unsqueeze(0)
+    im = im[:3].unsqueeze(0)
 
     # Build the corruption indexes we are going to use.
     jpegs = list(numpy.arange(opt['min_jpeg_correction'], opt['max_jpeg_correction'], opt['jpeg_correction_step_size']))
diff --git a/codes/scripts/diffusion/diffusion_noise_surfer.py b/codes/scripts/diffusion/diffusion_noise_surfer.py
index 805bb8c5..51bcc4f7 100644
--- a/codes/scripts/diffusion/diffusion_noise_surfer.py
+++ b/codes/scripts/diffusion/diffusion_noise_surfer.py
@@ -75,7 +75,7 @@ if __name__ == "__main__":
         im = im[:,dh:-dh]
     if dw > 0:
         im = im[:,:,dw:-dw]
-    im = im.unsqueeze(0)
+    im = im[:3].unsqueeze(0)
 
     # Build the corruption indexes we are going to use.
     correction_factors = opt['correction_factor']
diff --git a/codes/scripts/stitch_images.py b/codes/scripts/stitch_images.py
new file mode 100644
index 00000000..c63117eb
--- /dev/null
+++ b/codes/scripts/stitch_images.py
@@ -0,0 +1,20 @@
+import glob
+
+import torch
+import torchvision
+from PIL import Image
+from torchvision.transforms import ToTensor
+
+if __name__ == '__main__':
+    imfolder = 'F:\\dlas\\results\\test_diffusion_unet\\imgset5'
+    cols, rows = 10, 5
+    images = glob.glob(f'{imfolder}/*.png')
+    output = None
+    for r in range(rows):
+        for c in range(cols):
+            im = ToTensor()(Image.open(next(images)))
+            if output is None:
+                c, h, w = im.shape
+                output = torch.zeros(c, h * rows, w * cols)
+            output[:,r*h:(r+1)*h,c*w:(c+1)*w] = im
+    torchvision.utils.save_image(output, "out.png")
\ No newline at end of file
diff --git a/codes/train.py b/codes/train.py
index f95e4baf..917be288 100644
--- a/codes/train.py
+++ b/codes/train.py
@@ -299,7 +299,7 @@ class Trainer:
 
 if __name__ == '__main__':
     parser = argparse.ArgumentParser()
-    parser.add_argument('-opt', type=str, help='Path to option YAML file.', default='../options/train_imgset_unet_diffusion_sm.yml')
+    parser.add_argument('-opt', type=str, help='Path to option YAML file.', default='../options/train_imgset_unet_diffusion_xstart.yml')
     parser.add_argument('--launcher', choices=['none', 'pytorch'], default='none', help='job launcher')
     parser.add_argument('--local_rank', type=int, default=0)
     args = parser.parse_args()
diff --git a/codes/trainer/injectors/gaussian_diffusion_injector.py b/codes/trainer/injectors/gaussian_diffusion_injector.py
index be5273cf..69efda92 100644
--- a/codes/trainer/injectors/gaussian_diffusion_injector.py
+++ b/codes/trainer/injectors/gaussian_diffusion_injector.py
@@ -54,7 +54,7 @@ class GaussianDiffusionInferenceInjector(Injector):
         self.sampling_fn = self.diffusion.ddim_sample_loop if use_ddim else self.diffusion.p_sample_loop
         self.model_input_keys = opt_get(opt, ['model_input_keys'], [])
         self.use_ema_model = opt_get(opt, ['use_ema'], False)
-        self.zero_noise = opt_get(opt, ['zero_noise'], False)
+        self.noise_style = opt_get(opt, ['noise_type'], 'random')  # 'zero', 'fixed' or 'random'
 
     def forward(self, state):
         if self.use_ema_model:
@@ -66,7 +66,13 @@ class GaussianDiffusionInferenceInjector(Injector):
         with torch.no_grad():
             output_shape = (self.output_batch_size, 3, model_inputs['low_res'].shape[-2] * self.output_scale_factor,
                             model_inputs['low_res'].shape[-1] * self.output_scale_factor)
-            noise = torch.zeros(output_shape, device=model_inputs['low_res'].device) if self.zero_noise else None
+            noise = None
+            if self.noise_style == 'zero':
+                noise = torch.zeros(output_shape, device=model_inputs['low_res'].device)
+            elif self.noise_style == 'fixed':
+                if not hasattr(self, 'fixed_noise') or self.fixed_noise.shape != output_shape:
+                    self.fixed_noise = torch.randn(output_shape, device=model_inputs['low_res'].device)
+                noise = self.fixed_noise
             gen = self.sampling_fn(gen, output_shape, noise=noise, model_kwargs=model_inputs, progress=True)
             if self.undo_n1_to_1:
                 gen = (gen + 1) / 2