Files
Finetuning/architectures/WFNet.py
2026-07-03 13:31:43 +02:00

169 lines
6.7 KiB
Python

import torch
import torch.nn as nn
import torch.nn.functional as F
import torch.optim as optim
from torch.utils.data import DataLoader
import numpy as np
from sklearn.metrics import classification_report
from architectures.Model import Model
class WF_Module(nn.Module):
def __init__(self, original_model: nn.Module, num_classes: int, arch_enum):
super().__init__()
# If your model classes contain the raw inner torch model under an attribute,
# extract it. Otherwise, use it directly.
self.original_model = getattr(original_model, "model", original_model)
# Freeze the original model parameters completely
for param in self.original_model.parameters():
param.requires_grad = False
# Target layer discovery using your clean Enum contract
self.target_layer = self._deduce_target_layer(self.original_model, arch_enum)
# Derive channel dimensions dynamically from the deduced layer
out_channels = self._extract_channels(self.target_layer, self.original_model)
# Initialize alpha parameter matrix (Rows = Classes, Cols = Channels)
self.alpha = nn.Parameter(torch.full((num_classes, out_channels), 3.0))
self._current_target_indices = None
def _deduce_target_layer(self, model: nn.Module, arch_enum) -> nn.Module:
"""
Scans the architecture topology to target the final deep feature extraction block
right before global pooling/classification using strict Enum configurations.
"""
match arch_enum:
# --- RESNET FAMILY ---
case arch_enum.RESNET18 | arch_enum.RESNET34 | arch_enum.RESNET50 | arch_enum.WIDE_RESNET:
return model.layer4[-1]
# --- GOOGLENET ---
case arch_enum.GOOGLENET:
return model.inception5b
# --- INCEPTION V3 ---
case arch_enum.INCEPTION:
return model.Mixed_7c
# --- DENSENET 121 ---
case arch_enum.DENSENET121:
return model.features.norm5
# --- EFFICIENTNET ---
case arch_enum.EFFICIENTNET:
return model.features[-1]
# --- SHUFFLENET ---
case arch_enum.SHUFFLENET:
return model.conv5
case _:
# Robust Fallback Strategy
target = None
for module in model.modules():
if isinstance(module, nn.Conv2d):
target = module
if target is not None:
return target
raise RuntimeError(f"Could not locate filtration anchor for Enum target: {arch_enum}")
def _extract_channels(self, target_layer: nn.Module, model: nn.Module) -> int:
"""Helper to determine channel depth across varied layers types."""
if hasattr(target_layer, "out_channels"):
return target_layer.out_channels
if hasattr(target_layer, "num_features"):
return target_layer.num_features
if hasattr(target_layer, "weight"):
return target_layer.weight.shape[0]
# Classifier fallback mapping
if hasattr(model, "fc"):
return model.fc.in_features
if hasattr(model, "classifier"):
if isinstance(model.classifier, nn.Linear):
return model.classifier.in_features
if isinstance(model.classifier, nn.Sequential):
return model.classifier[0].in_features
return 512
def _filtration_hook(self, module: nn.Module, hook_input: tuple, hook_output: torch.Tensor) -> torch.Tensor:
if self._current_target_indices is None:
return hook_output
batch_alpha = self.alpha[self._current_target_indices]
if len(hook_output.shape) == 4:
mask = torch.sigmoid(batch_alpha).view(hook_output.size(0), -1, 1, 1)
else:
mask = torch.sigmoid(batch_alpha).view(hook_output.size(0), -1)
return hook_output * mask
def forward(self, x: torch.Tensor, target_class_indices: torch.Tensor) -> torch.Tensor:
self._current_target_indices = target_class_indices
hook_handle = self.target_layer.register_forward_hook(self._filtration_hook)
try:
logits = self.original_model(x)
finally:
hook_handle.remove()
self._current_target_indices = None
return logits
class WF_Net_Model(Model):
def __init__(self, device, size, original_model: nn.Module, target_class_index: int, arch):
self.device = device
self.size = size
self.wf_module = WF_Module(
arch_enum=arch,
original_model = original_model,
num_classes = size
).to(self.device)
# this index indicates which row of the mask should be active (gate closed).
self.target_class_index = target_class_index
self.model = self.wf_module
def get(self):
return self.wf_module
'''
We override the evaluate method from the base class,
because how we evaluate is different here from that of a normal torch nn.Module object
'''
def evaluate(self, loader, mode="eval"):
self.wf_module.eval()
all_preds, all_labels = [], []
print(f"\nEvaluating Domain: [{mode}]...")
with torch.no_grad():
for inputs, labels in loader:
inputs, labels = inputs.to(self.device), labels.to(self.device)
# we apply the filter
gate_signals = torch.full((inputs.size(0),), self.target_class_index, dtype=torch.long, device=self.device)
# pass prediction through the filter
outputs = self.wf_module(inputs, target_class_indices=gate_signals)
# return argmax(x)
_, predicted = torch.max(outputs, 1)
all_preds.extend(predicted.cpu().numpy())
all_labels.extend(labels.cpu().numpy())
classes = sorted(list(set(all_labels)))
accuracy = 100 * (np.array(all_preds) == np.array(all_labels)).sum() / len(all_labels)
print(f"Test Accuracy: {accuracy:.2f}%")
print(classification_report(all_labels, all_preds, labels=classes, zero_division=0))
report = classification_report(all_labels, all_preds, labels=classes, output_dict=True, zero_division=0)
return accuracy, report
def eval(self):
"""Safely intercept any fallback base class calls targeting .eval()"""
self.wf_module.eval()