From 6d1fc4c88d1b8b3af727b5f8e6ee4fbfcb13686c Mon Sep 17 00:00:00 2001
From: Falko Habel <falko.habel@gmx.de>
Date: Thu, 3 Jul 2025 09:53:10 +0200
Subject: [PATCH] bilinear upsampling followed by a convolution instead

---
 src/aiunn/upsampler/aiunn.py | 47 +++++++++++++++++++-----------------
 1 file changed, 25 insertions(+), 22 deletions(-)

diff --git a/src/aiunn/upsampler/aiunn.py b/src/aiunn/upsampler/aiunn.py
index f60952f..9db6ba9 100644
--- a/src/aiunn/upsampler/aiunn.py
+++ b/src/aiunn/upsampler/aiunn.py
@@ -1,39 +1,44 @@
-import os
-import torch
 import torch.nn as nn
-import warnings
 from aiia.model.Model import AIIAConfig, AIIABase
 from transformers import PreTrainedModel
 from .config import aiuNNConfig
-import warnings
+
 
 class aiuNN(PreTrainedModel):
     config_class = aiuNNConfig
+
     def __init__(self, config: aiuNNConfig, base_model: PreTrainedModel = None):
         super().__init__(config)
         self.config = config
+
+        # Copy base layers into aiuNN for self-containment and portability
         if base_model is not None:
-            # Only copy submodules if base_model is provided
-            self.base_layers = nn.Sequential(*[layer for layer in base_model.cnn])
+            if hasattr(base_model, 'cnn'):
+                self.base_layers = nn.Sequential(*[layer for layer in base_model.cnn])
+            elif hasattr(base_model, 'shared_layer') and hasattr(base_model, 'unique_layers'):
+                layers = [base_model.shared_layer, base_model.activation, base_model.max_pool]
+                for ul in base_model.unique_layers:
+                    layers.extend([ul, base_model.activation, base_model.max_pool])
+                self.base_layers = nn.Sequential(*layers)
+            else:
+                self.base_layers = self._build_base_layers_from_config(config)
         else:
-            # At inference, modules will be loaded from state_dict
             self.base_layers = self._build_base_layers_from_config(config)
 
-        scale_factor = self.config.upsample_scale
-        out_channels = self.config.num_channels * (scale_factor ** 2)
-        self.pixel_shuffle_conv = nn.Conv2d(
+        # Bilinear upsampling head
+        self.upsample = nn.Upsample(
+            scale_factor=self.config.upsample_scale,
+            mode='bilinear',
+            align_corners=False
+        )
+        self.final_conv = nn.Conv2d(
             in_channels=self.config.hidden_size,
-            out_channels=out_channels,
-            kernel_size=self.config.kernel_size,
+            out_channels=self.config.num_channels,
+            kernel_size=3,
             padding=1
         )
-        self.pixel_shuffle = nn.PixelShuffle(scale_factor)
 
     def _build_base_layers_from_config(self, config):
-        """
-        Reconstruct the base layers (e.g., CNN) using only the config.
-        This must match exactly how your base model builds its layers!
-        """
         layers = []
         in_channels = config.num_channels
         for _ in range(config.num_hidden_layers):
@@ -47,14 +52,12 @@ class aiuNN(PreTrainedModel):
         return nn.Sequential(*layers)
 
     def forward(self, x):
-        if self.base_layers is not None:
-            x = self.base_layers(x)
-        x = self.pixel_shuffle_conv(x)
-        x = self.pixel_shuffle(x)
+        x = self.base_layers(x)
+        x = self.upsample(x)
+        x = self.final_conv(x)
         return x
 
 
-
 if __name__ == "__main__":
     from aiia import AIIABase, AIIAConfig
     # Create a configuration and build a base model.