Signature-Verification / OModeling-2.py
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import os
import gc
import json
import math
import torch
import mlflow
import logging
import platform
import numpy as np
import pandas as pd
from PIL import Image
from tqdm import tqdm
import torch.nn as nn
import torch.optim as optim
from torchvision import models
import matplotlib.pyplot as plt
import torch.nn.functional as F
from sklearn.manifold import TSNE
from torchvision import transforms
from kymatio.torch import Scattering2D
from torch.utils.data import Dataset, DataLoader
from pytorch_metric_learning.miners import BatchHardMiner
from pytorch_metric_learning.losses import MultiSimilarityLoss
from torch.optim.lr_scheduler import CosineAnnealingLR, ReduceLROnPlateau
from sklearn.metrics import roc_curve, auc, precision_recall_fscore_support
from typing import Dict, List, Tuple, Optional, Union, Any
from dataclasses import dataclass, asdict
import warnings
warnings.filterwarnings('ignore')
# ----------------------------
# Configuration Management
# ----------------------------
@dataclass
@dataclass
class TrainingConfig:
# Model Architecture
model_name: str = "resnet34"
embedding_dim: int = 128
normalize_embeddings: bool = True
pretrained_path: Optional[str] = "../../model/pretrained_model/ResNet34.pt"
# Training Hyperparameters
batch_size: int = 512
max_epochs: int = 20
grad_accum_steps: int = 10
device: str = "cuda" if torch.cuda.is_available() else "cpu"
# Learning Rate Configuration
head_lr: float = 1e-3 # Higher LR for embedding head (untrained)
backbone_lr: float = 1e-4 # Lower LR for backbone (pretrained)
lr_scheduler: str = "cosine" # "cosine" or "plateau"
weight_decay: float = 1e-4
# Curriculum Learning Parameters - ADJUSTED FOR PRECISION
curriculum_strategy: str = "progressive" # "progressive", "exponential", "linear"
initial_hard_ratio: float = 0.6 # Increased from 0.1 for more hard negatives early
final_hard_ratio: float = 0.9 # Increased from 0.8 for focus on hard cases
curriculum_warmup_epochs: int = 1 # Reduced from 2 for faster hard sample exposure
# Data Augmentation
remove_bg: bool = False
augmentation_strength: float = 0.5 # 0.0 = no aug, 1.0 = strong aug
# Loss Configuration - ADJUSTED FOR PRECISION
multisim_alpha: float = 2.5 # Increased from 2.0 (penalize false positives more)
multisim_beta: float = 60.0 # Increased from 50.0 (larger margin)
multisim_base: float = 0.4 # Decreased from 0.5 (stricter similarity)
# Triplet Loss Parameters - NEW
triplet_margin: float = 1.0 # Margin for triplet loss
triplet_weight: float = 0.3 # Weight for triplet loss component
false_positive_penalty_weight: float = 0.3 # Extra penalty for false positives
# Mining Configuration
use_hard_mining: bool = True
# Precision Focus Parameters - NEW
target_precision: float = 0.75 # Target precision for threshold selection
negative_weight_multiplier: float = 2.5 # How much more to weight hard negatives
# Checkpoint Configuration
run_id: Optional[str] = None
last_epoch_weights: Optional[str] = None
save_frequency: int = 1 # Save every N epochs
# Early Stopping
patience: int = 15
min_delta: float = 0.001
# Logging
log_frequency: int = 100 # Log every N steps
visualize_frequency: int = 1 # Visualize every N epochs
tracking_uri: str = "http://127.0.0.1:5555"
def __post_init__(self):
"""Validate configuration parameters."""
assert 0.0 <= self.initial_hard_ratio <= 1.0, "Initial hard ratio must be in [0, 1]"
assert 0.0 <= self.final_hard_ratio <= 1.0, "Final hard ratio must be in [0, 1]"
assert self.curriculum_strategy in ["progressive", "exponential", "linear"]
assert self.lr_scheduler in ["cosine", "plateau"]
assert 0.0 <= self.target_precision <= 1.0, "Target precision must be in [0, 1]"
# Global configuration
CONFIG = TrainingConfig()
# ----------------------------
# MLFlow Setup
# ----------------------------
class MLFlowManager:
"""Centralized MLflow management for experiment tracking."""
def __init__(self, tracking_uri: str = "http://127.0.0.1:5555"):
mlflow.set_tracking_uri(tracking_uri)
self.experiment_name = "Signature Verification - Advanced Training"
self._setup_experiment()
def _setup_experiment(self):
"""Setup MLflow experiment."""
try:
self.experiment_id = mlflow.create_experiment(self.experiment_name)
except:
self.experiment_id = mlflow.get_experiment_by_name(self.experiment_name).experiment_id
def start_run(self, run_id: Optional[str] = None):
"""Start MLflow run with configuration logging."""
return mlflow.start_run(run_id=run_id, experiment_id=self.experiment_id)
def log_config(self, config: TrainingConfig):
"""Log training configuration."""
config_dict = asdict(config)
mlflow.log_params(config_dict)
# ----------------------------
# Curriculum Learning Manager
# ----------------------------
class CurriculumLearningManager:
"""Advanced curriculum learning for both hard positives and hard negatives."""
def __init__(self, config: TrainingConfig):
self.config = config
self.current_epoch = 0
def get_hard_ratio(self, epoch: int) -> float:
"""Get hard negative ratio (forgeries) for current epoch."""
if epoch < self.config.curriculum_warmup_epochs:
return self.config.initial_hard_ratio
# Target: reach final_hard_ratio by max_epochs // 2
target_epoch = max(self.config.max_epochs // 2, self.config.curriculum_warmup_epochs + 3)
if epoch >= target_epoch:
return self.config.final_hard_ratio
# Aggressive progression to reach target by mid-training
progress = (epoch - self.config.curriculum_warmup_epochs) / (target_epoch - self.config.curriculum_warmup_epochs)
initial = self.config.initial_hard_ratio
final = self.config.final_hard_ratio
if self.config.curriculum_strategy == "progressive":
# Very aggressive: exponential growth early, then plateau
ratio = initial + (final - initial) * (progress ** 0.5)
elif self.config.curriculum_strategy == "exponential":
ratio = initial + (final - initial) * (progress ** 0.3)
else: # linear
ratio = initial + (final - initial) * progress
return min(max(ratio, 0.0), 1.0)
def get_hard_positive_ratio(self, epoch: int) -> float:
"""Get hard positive ratio for current epoch - increases more gradually."""
if epoch < self.config.curriculum_warmup_epochs:
return 0.1 # Start with 10% hard positives
# Hard positives should increase more gradually than hard negatives
max_epochs = self.config.max_epochs
progress = min(1.0, (epoch - self.config.curriculum_warmup_epochs) / (max_epochs - self.config.curriculum_warmup_epochs))
# Target 40% hard positives by end of training
initial_ratio = 0.1
final_ratio = 0.4
if self.config.curriculum_strategy == "progressive":
ratio = initial_ratio + (final_ratio - initial_ratio) * (progress ** 0.7)
else:
ratio = initial_ratio + (final_ratio - initial_ratio) * progress
return min(max(ratio, 0.0), final_ratio)
def get_mining_difficulty(self, epoch: int) -> Dict[str, float]:
"""Adaptive mining parameters for both hard positives and negatives."""
progress = min(1.0, epoch / self.config.max_epochs)
# Separate ratios for hard positives and hard negatives
hard_negative_ratio = self.get_hard_ratio(epoch)
hard_positive_ratio = self.get_hard_positive_ratio(epoch)
# Dynamic weights for different sample types
hard_pos_weight = 1.0 + 2.0 * progress # 1.0 → 3.0
hard_neg_weight = 1.0 + 4.0 * progress # 1.0 → 5.0 (harder negatives more important)
return {
# Margin parameters
"margin_multiplier": 1.0 + 0.5 * progress,
# Hard sample ratios
"hard_negative_ratio": hard_negative_ratio,
"hard_positive_ratio": hard_positive_ratio,
"current_hard_ratio": hard_negative_ratio, # For backward compatibility
# Sample weights
"hard_positive_weight": hard_pos_weight,
"hard_negative_weight": hard_neg_weight,
"semi_positive_weight": 1.0 + 1.0 * progress,
"semi_negative_weight": 1.0 + 2.0 * progress,
# Difficulty thresholds
"difficulty_threshold": 0.05 + 0.15 * progress,
"selectivity": 0.8 + 0.2 * progress,
# Mining aggressiveness
"mining_temperature": max(0.5, 1.0 - 0.5 * progress), # Decreases over time
# Focus balance (0 = equal focus, 1 = focus on negatives)
"negative_focus": 0.5 + 0.3 * progress
}
# ----------------------------
# Enhanced Dataset with Advanced Curriculum Learning
# ----------------------------
class SignatureDataset(Dataset):
"""
Advanced signature dataset with curriculum learning and mining statistics.
"""
def __init__(
self,
folder_img: str,
excel_data: pd.DataFrame,
curriculum_manager: CurriculumLearningManager,
transform: Optional[transforms.Compose] = None,
is_train: bool = True,
config: TrainingConfig = CONFIG
):
self.folder_img = folder_img
self.is_train = is_train
self.config = config
self.curriculum_manager = curriculum_manager
self.transform = transform or self._default_transforms()
self.excel_data = excel_data.reset_index(drop=True)
self.current_epoch = 0
# Data preparation
self._handle_excel_person_ids()
self._categorize_difficulty()
# Curriculum learning data
self.epoch_data = []
self._prepare_epoch_data()
def _handle_excel_person_ids(self):
"""Properly separate genuine vs forged signature IDs with compact offset."""
# Map genuine person IDs to 0, 1, 2, ...
genuine_ids = pd.concat([
self.excel_data["anchor_id"],
self.excel_data[self.excel_data["easy_or_hard"] == "easy"]["negative_id"]
]).unique()
self.genuine_id_mapping = {val: idx for idx, val in enumerate(genuine_ids)}
max_genuine_id = len(genuine_ids)
# Create forgery ID space with SMALLER offset (just enough to avoid collisions)
forged_data = self.excel_data[self.excel_data["easy_or_hard"] == "hard"]
if len(forged_data) > 0:
unique_forged_persons = forged_data["negative_id"].unique()
self.forgery_id_mapping = {
val: idx + max_genuine_id + 100 # Smaller offset: 100 instead of 1000
for idx, val in enumerate(unique_forged_persons)
}
else:
self.forgery_id_mapping = {}
# Apply mappings
self.excel_data["anchor_id"] = self.excel_data["anchor_id"].map(self.genuine_id_mapping)
# Handle negatives based on type
new_negative_ids = []
for idx, row in self.excel_data.iterrows():
if row["easy_or_hard"] == "easy":
# Genuine different person: use regular ID
new_negative_ids.append(self.genuine_id_mapping[row["negative_id"]])
else:
# Forged signature: use offset ID to prevent clustering with genuine
new_negative_ids.append(self.forgery_id_mapping[row["negative_id"]])
self.excel_data["negative_id"] = new_negative_ids
print(f"ID mapping: Genuine IDs 0-{max_genuine_id-1}, Forgery IDs {max_genuine_id+100}-{max_genuine_id+100+len(self.forgery_id_mapping)-1}")
def _categorize_difficulty(self):
"""Categorize samples by difficulty if not already done."""
if self.is_train and "easy_or_hard" in self.excel_data.columns:
self.easy_df = self.excel_data[self.excel_data["easy_or_hard"] == "easy"]
self.hard_df = self.excel_data[self.excel_data["easy_or_hard"] == "hard"]
else:
# All samples treated as medium difficulty
self.easy_df = self.excel_data
self.hard_df = pd.DataFrame() # Empty hard samples
def _prepare_epoch_data(self):
"""Prepare data for current epoch based on curriculum."""
if not self.is_train:
# Validation data preparation with better error handling
if "image_1_path" in self.excel_data.columns and "image_2_path" in self.excel_data.columns:
# Standard pair format
required_cols = ["image_1_path", "image_2_path", "label"]
# Find ID columns
id_cols = [col for col in self.excel_data.columns if "id" in col.lower()]
if len(id_cols) >= 2:
required_cols.extend(id_cols[-2:]) # Take last 2 ID columns
else:
# Create dummy IDs if none exist
self.excel_data["dummy_id1"] = 0
self.excel_data["dummy_id2"] = 1
required_cols.extend(["dummy_id1", "dummy_id2"])
self.epoch_data = self.excel_data[required_cols].values.tolist()
else:
# Fallback: try to use all available columns
print(f"Warning: Expected validation columns not found. Available: {list(self.excel_data.columns)}")
self.epoch_data = self.excel_data.values.tolist()
print(f"Validation data prepared: {len(self.epoch_data)} samples")
return
# Training data preparation (unchanged)
hard_ratio = self.curriculum_manager.get_hard_ratio(self.current_epoch)
if len(self.hard_df) > 0:
n_total = len(self.excel_data)
n_hard = int(n_total * hard_ratio)
n_easy = n_total - n_hard
hard_sample = self.hard_df.sample(
n=min(n_hard, len(self.hard_df)),
random_state=self.current_epoch,
replace=(n_hard > len(self.hard_df))
)
easy_sample = self.easy_df.sample(
n=min(n_easy, len(self.easy_df)),
random_state=self.current_epoch,
replace=(n_easy > len(self.easy_df))
)
epoch_df = pd.concat([hard_sample, easy_sample]).sample(
frac=1, random_state=self.current_epoch
).reset_index(drop=True)
print(f"Epoch {self.current_epoch}: {len(hard_sample)} hard + {len(easy_sample)} easy = {len(epoch_df)} total (target ratio: {hard_ratio:.2f})")
else:
epoch_df = self.excel_data.sample(
frac=1, random_state=self.current_epoch
).reset_index(drop=True)
required_cols = ["anchor_path", "positive_path", "negative_path", "anchor_id", "negative_id"]
missing_cols = [col for col in required_cols if col not in epoch_df.columns]
if missing_cols:
raise ValueError(f"Missing required training columns: {missing_cols}")
self.epoch_data = epoch_df[required_cols].values.tolist()
def set_epoch(self, epoch: int):
"""Update epoch and regenerate data."""
self.current_epoch = epoch
self._prepare_epoch_data()
def get_curriculum_stats(self) -> Dict[str, Any]:
"""Get current curriculum learning statistics."""
hard_ratio = self.curriculum_manager.get_hard_ratio(self.current_epoch)
mining_params = self.curriculum_manager.get_mining_difficulty(self.current_epoch)
return {
"epoch": self.current_epoch,
"hard_ratio": hard_ratio,
"easy_ratio": 1.0 - hard_ratio,
"total_samples": len(self.epoch_data),
**mining_params
}
def __len__(self) -> int:
return len(self.epoch_data)
def __getitem__(self, index: int) -> Tuple[torch.Tensor, ...]:
if self.is_train:
return self._get_train_item(index)
else:
return self._get_val_item(index)
def _get_train_item(self, index: int) -> Tuple[torch.Tensor, torch.Tensor, torch.Tensor, int, int]:
"""Return triplet: anchor, positive, negative with their IDs."""
anchor_path, positive_path, negative_path, pid, nid = self.epoch_data[index]
anchor = self._load_image(anchor_path)
positive = self._load_image(positive_path)
negative = self._load_image(negative_path)
return anchor, positive, negative, int(pid), int(nid)
def _get_val_item(self, index: int) -> Tuple[torch.Tensor, torch.Tensor, torch.Tensor, int, int]:
"""Return: img1, img2, label, id1, id2."""
data_row = self.epoch_data[index]
# Handle different data formats robustly
if len(data_row) >= 5:
img1_path, img2_path, label, id1, id2 = data_row[:5]
elif len(data_row) >= 3:
img1_path, img2_path, label = data_row[:3]
# Fallback IDs
id1, id2 = 0, 1
else:
raise ValueError(f"Invalid validation data format: expected at least 3 columns, got {len(data_row)}")
try:
img1 = self._load_image(img1_path)
img2 = self._load_image(img2_path)
return img1, img2, torch.tensor(float(label), dtype=torch.float32), int(id1), int(id2)
except Exception as e:
print(f"Error loading validation item {index}: {e}")
print(f"Data row: {data_row}")
raise
def _load_image(self, path: str) -> torch.Tensor:
"""Load and transform image."""
image = replace_background_with_white(
path, self.folder_img, remove_bg=self.config.remove_bg
)
return self.transform(image) if self.transform else image
def _default_transforms(self) -> transforms.Compose:
"""Get default transforms with configurable augmentation strength."""
normalize = transforms.Normalize(
mean=[0.485, 0.456, 0.406],
std=[0.229, 0.224, 0.225]
)
if self.is_train:
aug_strength = self.config.augmentation_strength
return transforms.Compose([
transforms.Resize((224, 224)),
transforms.RandomHorizontalFlip(p=0.5 * aug_strength),
transforms.RandomRotation(degrees=int(10 * aug_strength)),
transforms.ColorJitter(
brightness=0.2 * aug_strength,
contrast=0.2 * aug_strength
),
transforms.GaussianBlur(kernel_size=5, sigma=(0.1, 2.0 * aug_strength)),
transforms.ToTensor(),
normalize
])
return transforms.Compose([
transforms.Resize((224, 224)),
transforms.ToTensor(),
normalize
])
# ----------------------------
# Enhanced Model Architecture
# ----------------------------
class ResNetBackbone(nn.Module):
"""Enhanced ResNet backbone with better weight loading."""
def __init__(self, model_name: str = "resnet34", pretrained_path: Optional[str] = None):
super().__init__()
# Initialize the ResNet model
if model_name == "resnet18":
self.resnet = models.resnet18(weights=None)
elif model_name == "resnet34":
self.resnet = models.resnet34(weights=None)
elif model_name == "resnet50":
self.resnet = models.resnet50(weights=None)
else:
raise ValueError(f"Unsupported model_name: {model_name}")
# Load pretrained weights
if pretrained_path and os.path.exists(pretrained_path):
self._load_pretrained_weights(pretrained_path)
elif pretrained_path:
print(f"Warning: Pretrained path {pretrained_path} not found, using random initialization")
# Remove the fully connected layer
self.resnet.fc = nn.Identity()
# Get output dimension
with torch.no_grad():
dummy = torch.randn(1, 3, 224, 224)
self.output_dim = self.resnet(dummy).shape[1]
def _load_pretrained_weights(self, pretrained_path: str):
"""Load pretrained weights with comprehensive error handling."""
try:
checkpoint = torch.load(pretrained_path, map_location="cpu", weights_only=False)
state_dict = checkpoint.get("state_dict", checkpoint)
# Handle prefix issues
if not any(key.startswith("resnet.") for key in state_dict.keys()):
state_dict = {f"resnet.{k}": v for k, v in state_dict.items()}
# Filter matching keys and sizes
model_dict = self.state_dict()
filtered_state_dict = {
k: v for k, v in state_dict.items()
if k in model_dict and v.size() == model_dict[k].size()
}
# Load filtered weights
missing_keys = self.load_state_dict(filtered_state_dict, strict=False)
print(f"[INFO] Loaded pretrained weights: {len(filtered_state_dict)}/{len(model_dict)} parameters")
if missing_keys.missing_keys:
print(f"[INFO] Missing keys: {len(missing_keys.missing_keys)}")
except Exception as e:
print(f"[ERROR] Failed to load pretrained weights: {e}")
raise
def forward(self, x: torch.Tensor) -> torch.Tensor:
return self.resnet(x)
class AdvancedEmbeddingHead(nn.Module):
"""Advanced embedding head with residual connections and normalization."""
def __init__(self, input_dim: int, embedding_dim: int, dropout: float = 0.5):
super().__init__()
self.input_dim = input_dim
self.embedding_dim = embedding_dim
# Multi-layer embedding head with residual connections
if input_dim > embedding_dim * 4:
hidden_dim = max(embedding_dim * 2, input_dim // 4)
self.layers = nn.Sequential(
nn.Linear(input_dim, hidden_dim),
nn.LayerNorm(hidden_dim),
nn.GELU(),
nn.Dropout(dropout),
nn.Linear(hidden_dim, embedding_dim * 2),
nn.LayerNorm(embedding_dim * 2),
nn.GELU(),
nn.Dropout(dropout / 2),
nn.Linear(embedding_dim * 2, embedding_dim),
nn.LayerNorm(embedding_dim)
)
else:
# Simple head for smaller dimensions
self.layers = nn.Sequential(
nn.Linear(input_dim, embedding_dim),
nn.LayerNorm(embedding_dim)
)
def forward(self, x: torch.Tensor) -> torch.Tensor:
x = x.flatten(1) # Flatten spatial dimensions
return self.layers(x)
class SiameseSignatureNetwork(nn.Module):
"""Advanced Siamese network with precision-focused loss."""
def __init__(self, config: TrainingConfig = CONFIG):
super().__init__()
self.config = config
# Initialize backbone
if config.model_name.startswith("resnet"):
self.backbone = ResNetBackbone(
model_name=config.model_name,
pretrained_path=config.pretrained_path if config.last_epoch_weights is None else None
)
backbone_dim = self.backbone.output_dim
else:
raise ValueError(f"Unsupported model: {config.model_name}")
# Initialize embedding head
self.embedding_head = AdvancedEmbeddingHead(
input_dim=backbone_dim,
embedding_dim=config.embedding_dim,
dropout=0.5
)
self.normalize_embeddings = config.normalize_embeddings
self.distance_threshold = 0.5 # Will be updated during validation
# Loss components
self.criterion = MultiSimilarityLoss(
alpha=config.multisim_alpha,
beta=config.multisim_beta,
base=config.multisim_base
)
# Add triplet margin loss for better separation
self.triplet_loss = nn.TripletMarginLoss(
margin=config.triplet_margin,
p=2,
reduction='none' # We'll apply weights manually
)
# Loss weights
self.triplet_weight = config.triplet_weight
self.fp_penalty_weight = config.false_positive_penalty_weight
# Mining
if config.use_hard_mining:
self.miner = BatchHardMiner()
else:
self.miner = None
def get_parameter_groups(self) -> List[Dict[str, Any]]:
"""Get parameter groups for differential learning rates."""
backbone_params = list(self.backbone.parameters())
head_params = list(self.embedding_head.parameters())
return [
{
'params': backbone_params,
'lr': self.config.backbone_lr,
'name': 'backbone',
'weight_decay': self.config.weight_decay
},
{
'params': head_params,
'lr': self.config.head_lr,
'name': 'embedding_head',
'weight_decay': self.config.weight_decay
}
]
def forward(self, anchor: torch.Tensor, positive: torch.Tensor,
negative: Optional[torch.Tensor] = None) -> Union[Tuple[torch.Tensor, torch.Tensor],
Tuple[torch.Tensor, torch.Tensor, torch.Tensor]]:
"""Forward pass for training or inference."""
a_features = self.backbone(anchor)
a_emb = self.embedding_head(a_features)
p_features = self.backbone(positive)
p_emb = self.embedding_head(p_features)
if self.normalize_embeddings:
a_emb = F.normalize(a_emb, p=2, dim=1)
p_emb = F.normalize(p_emb, p=2, dim=1)
if negative is not None:
n_features = self.backbone(negative)
n_emb = self.embedding_head(n_features)
if self.normalize_embeddings:
n_emb = F.normalize(n_emb, p=2, dim=1)
return a_emb, p_emb, n_emb
return a_emb, p_emb
def compute_loss(self, embeddings: torch.Tensor, labels: torch.Tensor,
anchors: Optional[torch.Tensor] = None,
positives: Optional[torch.Tensor] = None,
negatives: Optional[torch.Tensor] = None,
distance_weights: Optional[Dict[str, torch.Tensor]] = None) -> torch.Tensor:
"""Enhanced loss computation with precision focus and distance weighting."""
# MultiSimilarity loss
if self.miner is not None:
hard_pairs = self.miner(embeddings, labels)
ms_loss = self.criterion(embeddings, labels, hard_pairs)
else:
ms_loss = self.criterion(embeddings, labels)
total_loss = ms_loss
# Add triplet loss if embeddings provided
if anchors is not None and positives is not None and negatives is not None:
# Compute triplet losses for each sample
triplet_losses = self.triplet_loss(anchors, positives, negatives)
# Apply distance-based weights if provided
if distance_weights is not None:
neg_weights = distance_weights.get('negative_weights', torch.ones_like(triplet_losses))
weighted_triplet_loss = (triplet_losses * neg_weights).mean()
else:
weighted_triplet_loss = triplet_losses.mean()
total_loss += self.triplet_weight * weighted_triplet_loss
# Additional penalty for hard negatives (false positives)
with torch.no_grad():
d_an = F.pairwise_distance(anchors, negatives)
# Find negatives that are too close (potential false positives)
hard_negative_mask = d_an < self.distance_threshold
if hard_negative_mask.any():
# Apply distance-based weights for false positive penalty
if distance_weights is not None:
neg_weights = distance_weights.get('negative_weights', torch.ones_like(d_an))
# Extra penalty weighted by how bad the false positive is
false_positive_distances = self.distance_threshold - d_an[hard_negative_mask]
false_positive_weights = neg_weights[hard_negative_mask]
fp_loss = (false_positive_distances * false_positive_weights).mean()
else:
fp_loss = (self.distance_threshold - d_an[hard_negative_mask]).mean()
total_loss += self.fp_penalty_weight * fp_loss
return total_loss
def predict_pair(self, img1: torch.Tensor, img2: torch.Tensor,
threshold: Optional[float] = None, return_dist: bool = False) -> torch.Tensor:
"""Predict similarity between image pairs."""
self.eval()
with torch.no_grad():
emb1, emb2 = self(img1, img2)
distances = F.pairwise_distance(emb1, emb2)
if return_dist:
return distances
thresh = threshold if threshold is not None else self.distance_threshold
return (distances < thresh).long()
# ----------------------------
# Advanced Training Metrics and Statistics
# ----------------------------
class TrainingMetrics:
"""Enhanced training metrics with adaptive mining for both hard positives and negatives."""
def __init__(self):
self.reset()
# Track distance statistics for adaptive thresholds
self.distance_history = {"positive": [], "negative": []}
self.adaptive_stats = {}
def reset(self):
"""Reset all metrics."""
self.losses = []
self.genuine_distances = []
self.forged_distances = []
# Separate mining stats for positives and negatives
self.positive_mining_stats = {"easy": 0, "semi": 0, "hard": 0}
self.negative_mining_stats = {"easy": 0, "semi": 0, "hard": 0}
# Hard sample counts
self.hard_positive_count = 0
self.hard_negative_count = 0
self.total_positive_pairs = 0
self.total_negative_pairs = 0
# False positive/negative tracking
self.false_positive_count = 0
self.false_negative_count = 0
self.learning_rates = {}
def update_distance_statistics(self, d_positive: np.ndarray, d_negative: np.ndarray):
"""Update running statistics for adaptive thresholds."""
# Keep rolling window of recent distances
self.distance_history["positive"].extend(d_positive.tolist())
self.distance_history["negative"].extend(d_negative.tolist())
# Keep only recent history (last 5000 samples)
for key in self.distance_history:
if len(self.distance_history[key]) > 5000:
self.distance_history[key] = self.distance_history[key][-5000:]
# Compute adaptive statistics
if len(self.distance_history["positive"]) > 100 and len(self.distance_history["negative"]) > 100:
pos_distances = np.array(self.distance_history["positive"])
neg_distances = np.array(self.distance_history["negative"])
self.adaptive_stats = {
"pos_mean": np.mean(pos_distances),
"pos_std": np.std(pos_distances),
"pos_q25": np.percentile(pos_distances, 25),
"pos_q50": np.percentile(pos_distances, 50),
"pos_q75": np.percentile(pos_distances, 75),
"pos_q90": np.percentile(pos_distances, 90),
"neg_mean": np.mean(neg_distances),
"neg_std": np.std(neg_distances),
"neg_q10": np.percentile(neg_distances, 10),
"neg_q25": np.percentile(neg_distances, 25),
"neg_q50": np.percentile(neg_distances, 50),
"neg_q75": np.percentile(neg_distances, 75),
"separation": np.mean(neg_distances) - np.mean(pos_distances),
"overlap_region": max(0, np.percentile(pos_distances, 95) - np.percentile(neg_distances, 5))
}
def compute_precision_focused_weights(self, d_positive: np.ndarray,
d_negative: np.ndarray,
negative_weight_multiplier: float = 2.5) -> Tuple[torch.Tensor, torch.Tensor]:
"""Compute sample weights with focus on improving precision."""
pos_weights = np.ones_like(d_positive)
neg_weights = np.ones_like(d_negative)
if self.adaptive_stats:
# Hard negatives (forged that look genuine) get MUCH higher weight
neg_q10 = self.adaptive_stats["neg_q10"]
neg_q25 = self.adaptive_stats["neg_q25"]
# Very hard negatives (bottom 10%) - highest weight
very_hard_neg_mask = d_negative < neg_q10
neg_weights[very_hard_neg_mask] = negative_weight_multiplier * 1.5
# Hard negatives (10-25%) - high weight
hard_neg_mask = (d_negative >= neg_q10) & (d_negative < neg_q25)
neg_weights[hard_neg_mask] = negative_weight_multiplier
# Semi-hard negatives (25-50%) - moderate weight
semi_neg_mask = (d_negative >= neg_q25) & (d_negative < self.adaptive_stats["neg_q50"])
neg_weights[semi_neg_mask] = negative_weight_multiplier * 0.6
# Hard positives get moderate weight (but less than hard negatives)
pos_q75 = self.adaptive_stats["pos_q75"]
pos_q90 = self.adaptive_stats["pos_q90"]
# Very hard positives (top 10%)
very_hard_pos_mask = d_positive > pos_q90
pos_weights[very_hard_pos_mask] = 1.8
# Hard positives (75-90%)
hard_pos_mask = (d_positive > pos_q75) & (d_positive <= pos_q90)
pos_weights[hard_pos_mask] = 1.5
return torch.tensor(pos_weights, dtype=torch.float32), torch.tensor(neg_weights, dtype=torch.float32)
def update_mining_stats(self, d_positive: np.ndarray, d_negative: np.ndarray,
margin: float, difficulty_params: Dict[str, float]):
"""Intelligent adaptive mining for both hard positives and hard negatives."""
# Update distance statistics first
self.update_distance_statistics(d_positive, d_negative)
# Update totals
self.total_positive_pairs += len(d_positive)
self.total_negative_pairs += len(d_negative)
# Use adaptive thresholds if available, otherwise fallback to fixed
if self.adaptive_stats:
self._adaptive_mining(d_positive, d_negative, difficulty_params)
else:
self._fixed_mining(d_positive, d_negative, margin)
def _adaptive_mining(self, d_positive: np.ndarray, d_negative: np.ndarray,
difficulty_params: Dict[str, float]):
"""Adaptive mining based on current distance distributions."""
stats = self.adaptive_stats
# Get difficulty parameters
hard_positive_ratio = difficulty_params.get("hard_positive_ratio", 0.3)
hard_negative_ratio = difficulty_params.get("hard_negative_ratio", 0.3)
# Dynamic thresholds for hard positives (far apart genuine pairs)
# Use percentile based on desired hard positive ratio
hard_pos_percentile = 100 - (hard_positive_ratio * 100)
hard_pos_threshold = np.percentile(self.distance_history["positive"][-1000:], hard_pos_percentile)
semi_pos_threshold = stats["pos_q50"]
# Dynamic thresholds for hard negatives (close together impostor pairs)
# Use percentile based on desired hard negative ratio
hard_neg_percentile = hard_negative_ratio * 100
hard_neg_threshold = np.percentile(self.distance_history["negative"][-1000:], hard_neg_percentile)
semi_neg_threshold = stats["neg_q50"]
# Mine hard positives
for dp in d_positive:
if dp >= hard_pos_threshold:
self.positive_mining_stats["hard"] += 1
self.hard_positive_count += 1
elif dp >= semi_pos_threshold:
self.positive_mining_stats["semi"] += 1
else:
self.positive_mining_stats["easy"] += 1
# Mine hard negatives
for dn in d_negative:
if dn <= hard_neg_threshold:
self.negative_mining_stats["hard"] += 1
self.hard_negative_count += 1
elif dn <= semi_neg_threshold:
self.negative_mining_stats["semi"] += 1
else:
self.negative_mining_stats["easy"] += 1
def _fixed_mining(self, d_positive: np.ndarray, d_negative: np.ndarray, margin: float):
"""Fallback fixed mining for early epochs."""
# Fixed thresholds
hard_pos_threshold = 0.5 # Far genuine pairs
hard_neg_threshold = 0.3 # Close impostor pairs
for dp in d_positive:
if dp >= hard_pos_threshold:
self.positive_mining_stats["hard"] += 1
self.hard_positive_count += 1
elif dp >= hard_pos_threshold * 0.7:
self.positive_mining_stats["semi"] += 1
else:
self.positive_mining_stats["easy"] += 1
for dn in d_negative:
if dn <= hard_neg_threshold:
self.negative_mining_stats["hard"] += 1
self.hard_negative_count += 1
elif dn <= hard_neg_threshold * 1.5:
self.negative_mining_stats["semi"] += 1
else:
self.negative_mining_stats["easy"] += 1
def get_mining_percentages(self) -> Dict[str, float]:
"""Get mining statistics as percentages with debugging info."""
total_pos = sum(self.positive_mining_stats.values())
total_neg = sum(self.negative_mining_stats.values())
percentages = {}
# Positive pair mining stats
if total_pos > 0:
percentages.update({
"pos_mining_easy_pct": 100.0 * self.positive_mining_stats["easy"] / total_pos,
"pos_mining_semi_pct": 100.0 * self.positive_mining_stats["semi"] / total_pos,
"pos_mining_hard_pct": 100.0 * self.positive_mining_stats["hard"] / total_pos,
})
else:
percentages.update({
"pos_mining_easy_pct": 0.0,
"pos_mining_semi_pct": 0.0,
"pos_mining_hard_pct": 0.0,
})
# Negative pair mining stats
if total_neg > 0:
percentages.update({
"neg_mining_easy_pct": 100.0 * self.negative_mining_stats["easy"] / total_neg,
"neg_mining_semi_pct": 100.0 * self.negative_mining_stats["semi"] / total_neg,
"neg_mining_hard_pct": 100.0 * self.negative_mining_stats["hard"] / total_neg,
})
else:
percentages.update({
"neg_mining_easy_pct": 0.0,
"neg_mining_semi_pct": 0.0,
"neg_mining_hard_pct": 0.0,
})
# Overall hard sample ratios
if self.total_positive_pairs > 0:
percentages["hard_positive_ratio"] = 100.0 * self.hard_positive_count / self.total_positive_pairs
else:
percentages["hard_positive_ratio"] = 0.0
if self.total_negative_pairs > 0:
percentages["hard_negative_ratio"] = 100.0 * self.hard_negative_count / self.total_negative_pairs
else:
percentages["hard_negative_ratio"] = 0.0
# False positive/negative rates
total_samples = self.total_positive_pairs + self.total_negative_pairs
if total_samples > 0:
percentages["false_positive_rate"] = 100.0 * self.false_positive_count / self.total_negative_pairs if self.total_negative_pairs > 0 else 0.0
percentages["false_negative_rate"] = 100.0 * self.false_negative_count / self.total_positive_pairs if self.total_positive_pairs > 0 else 0.0
# Add adaptive stats if available
if self.adaptive_stats:
percentages.update({
"adaptive_separation": self.adaptive_stats["separation"],
"adaptive_overlap": self.adaptive_stats["overlap_region"],
"adaptive_pos_spread": self.adaptive_stats["pos_std"],
"adaptive_neg_spread": self.adaptive_stats["neg_std"],
})
return percentages
def compute_separation_metrics(self) -> Dict[str, float]:
"""Compute distance separation metrics."""
if not self.genuine_distances or not self.forged_distances:
return {
"genuine_dist_mean": 0.0,
"forged_dist_mean": 0.0,
"genuine_dist_std": 0.0,
"forged_dist_std": 0.0,
"separation": 0.0,
"overlap": 0.0,
"separation_ratio": 0.0,
"cohesion_ratio": 0.0
}
gen_mean = np.mean(self.genuine_distances)
forg_mean = np.mean(self.forged_distances)
gen_std = np.std(self.genuine_distances)
forg_std = np.std(self.forged_distances)
separation = forg_mean - gen_mean
overlap = max(0, gen_mean + 2*gen_std - (forg_mean - 2*forg_std))
# Cohesion ratio: how tight are genuine pairs relative to separation
cohesion_ratio = gen_std / (separation + 1e-8)
return {
"genuine_dist_mean": gen_mean,
"forged_dist_mean": forg_mean,
"genuine_dist_std": gen_std,
"forged_dist_std": forg_std,
"separation": separation,
"overlap": overlap,
"separation_ratio": separation / (gen_std + forg_std + 1e-8),
"cohesion_ratio": cohesion_ratio
}
# ----------------------------
# Enhanced Training Loop
# ----------------------------
class SignatureTrainer:
"""Research-grade signature verification trainer."""
def __init__(self, config: TrainingConfig = CONFIG):
self.config = config
self.device = torch.device(config.device)
# Initialize managers
self.mlflow_manager = MLFlowManager(tracking_uri=self.config.tracking_uri)
self.curriculum_manager = CurriculumLearningManager(config)
# Training state
self.current_epoch = 0
self.best_eer = float('inf')
self.patience_counter = 0
self.global_step = 0
# Setup logging
self._setup_logging()
def _setup_logging(self):
"""Setup comprehensive logging."""
logging.basicConfig(
level=logging.INFO,
format='%(asctime)s - %(levelname)s - %(message)s',
handlers=[
logging.FileHandler('training.log'),
logging.StreamHandler()
]
)
self.logger = logging.getLogger(__name__)
def _prepare_datasets(self) -> Tuple[SignatureDataset, SignatureDataset]:
"""Prepare training and validation datasets."""
# Load datasets
train_data = pd.read_excel("../../data/classify/preprared_data/labels/train_triplets_balanced_v12.xlsx")
val_data = pd.read_excel("../../data/classify/preprared_data/labels/valid_pairs_balanced_v12.xlsx")
train_dataset = SignatureDataset(
folder_img="../../data/classify/preprared_data/images/",
excel_data=train_data,
curriculum_manager=self.curriculum_manager,
is_train=True,
config=self.config
)
val_dataset = SignatureDataset(
folder_img="../../data/classify/preprared_data/images/",
excel_data=val_data,
curriculum_manager=self.curriculum_manager,
is_train=False,
config=self.config
)
self.logger.info(f"Training samples: {len(train_dataset)}")
self.logger.info(f"Validation samples: {len(val_dataset)}")
return train_dataset, val_dataset
def _compute_precision_optimized_threshold(self, distances: np.ndarray,
labels: np.ndarray,
target_precision: float = None) -> float:
"""Find threshold that achieves target precision while maximizing F1."""
if target_precision is None:
target_precision = self.config.target_precision
thresholds = np.linspace(distances.min(), distances.max(), 1000)
best_threshold = thresholds[0]
best_f1 = 0
best_precision = 0
best_recall = 0
for thresh in thresholds:
predictions = (distances < thresh).astype(int)
# Calculate metrics
tp = np.sum((predictions == 1) & (labels == 1))
fp = np.sum((predictions == 1) & (labels == 0))
fn = np.sum((predictions == 0) & (labels == 1))
precision = tp / (tp + fp + 1e-8)
recall = tp / (tp + fn + 1e-8)
f1 = 2 * precision * recall / (precision + recall + 1e-8)
# Prioritize precision while maintaining reasonable recall
if precision >= target_precision and f1 > best_f1:
best_f1 = f1
best_threshold = thresh
best_precision = precision
best_recall = recall
# If we can't achieve target precision, get best precision with recall > 0.5
elif precision > best_precision and recall > 0.5:
best_f1 = f1
best_threshold = thresh
best_precision = precision
best_recall = recall
print(f" Precision-optimized threshold: {best_threshold:.4f} "
f"(P: {best_precision:.3f}, R: {best_recall:.3f}, F1: {best_f1:.3f})")
return best_threshold
def _setup_model_and_optimizer(self) -> Tuple[SiameseSignatureNetwork, torch.optim.Optimizer, Any]:
"""Setup model, optimizer, and scheduler."""
# Initialize model
model = SiameseSignatureNetwork(self.config)
# Compile model if available
if hasattr(torch, "compile") and platform.system() != "Windows":
self.logger.info("Compiling model with torch.compile")
model = torch.compile(model)
model = model.to(self.device)
# Count parameters
total_params = sum(p.numel() for p in model.parameters())
trainable_params = sum(p.numel() for p in model.parameters() if p.requires_grad)
self.logger.info(f"Total parameters: {total_params:,}")
self.logger.info(f"Trainable parameters: {trainable_params:,}")
# Setup optimizer with parameter groups
param_groups = model.get_parameter_groups()
optimizer = torch.optim.AdamW(param_groups)
# Log learning rates
for group in param_groups:
self.logger.info(f"Parameter group '{group['name']}': LR = {group['lr']:.2e}")
# Setup scheduler
if self.config.lr_scheduler == "cosine":
scheduler = CosineAnnealingLR(optimizer, T_max=self.config.max_epochs)
else:
scheduler = ReduceLROnPlateau(optimizer, mode='min', patience=5, factor=0.5)
return model, optimizer, scheduler
def _setup_checkpoint_management(self, run_id: str) -> Tuple[str, str]:
"""Setup checkpoint directories."""
checkpoint_dir = os.path.join("../../model/models_checkpoints/", run_id)
figures_dir = os.path.join(checkpoint_dir, "figures")
os.makedirs(checkpoint_dir, exist_ok=True)
os.makedirs(figures_dir, exist_ok=True)
return checkpoint_dir, figures_dir
def _load_checkpoint(self, model: nn.Module, optimizer: torch.optim.Optimizer,
scheduler: Any, scaler: torch.amp.GradScaler) -> int:
"""Load checkpoint if specified."""
if not self.config.last_epoch_weights:
return 1
checkpoint_path = self.config.last_epoch_weights
self.logger.info(f"Loading checkpoint from {checkpoint_path}")
try:
checkpoint = torch.load(checkpoint_path, map_location=self.device, weights_only=False)
model.load_state_dict(checkpoint["model_state_dict"])
optimizer.load_state_dict(checkpoint["optimizer_state_dict"])
scheduler.load_state_dict(checkpoint["scheduler_state_dict"])
scaler.load_state_dict(checkpoint.get("scaler_state_dict", scaler.state_dict()))
start_epoch = checkpoint["epoch"] + 1
self.best_eer = checkpoint.get("best_eer", self.best_eer)
model.distance_threshold = checkpoint.get("prediction_threshold", 0.5)
self.logger.info(f"Resumed from epoch {start_epoch}, best EER: {self.best_eer:.4f}")
return start_epoch
except Exception as e:
self.logger.error(f"Failed to load checkpoint: {e}")
return 1
def train_epoch(self, model: nn.Module, train_loader: DataLoader,
optimizer: torch.optim.Optimizer, scaler: torch.amp.GradScaler,
epoch: int) -> TrainingMetrics:
"""Enhanced training with intelligent adaptive mining for both hard positives and negatives."""
model.train()
metrics = TrainingMetrics()
curriculum_stats = train_loader.dataset.get_curriculum_stats()
# INTELLIGENT MARGIN CALCULATION
base_margin = 0.5 # Base margin for normalized embeddings
margin_multiplier = curriculum_stats["margin_multiplier"]
adaptive_margin = base_margin * margin_multiplier
# Progressive margin adjustment based on epoch
epoch_progress = epoch / self.config.max_epochs
progressive_factor = 1.2 - 0.4 * epoch_progress # 1.2 → 0.8
final_margin = adaptive_margin * progressive_factor
# Tracking counters
forgery_batch_count = 0
genuine_batch_count = 0
batch_fp_count = 0
batch_fn_count = 0
# Debug info
debug_printed = False
pbar = tqdm(train_loader, desc=f"[Train] Epoch {epoch}")
for step, (anchors, positives, negatives, anchor_ids, negative_ids) in enumerate(pbar):
# Move to device
anchors = anchors.to(self.device, non_blocking=True)
positives = positives.to(self.device, non_blocking=True)
negatives = negatives.to(self.device, non_blocking=True)
anchor_ids = anchor_ids.to(self.device, non_blocking=True)
negative_ids = negative_ids.to(self.device, non_blocking=True)
# Count forgery vs genuine negatives
max_genuine_id = len(train_loader.dataset.genuine_id_mapping)
forgery_mask = negative_ids >= max_genuine_id + 100
forgery_batch_count += forgery_mask.sum().item()
genuine_batch_count += (~forgery_mask).sum().item()
if not debug_printed and step == 0:
print(f"\n[DEBUG Epoch {epoch}]")
print(f" Final margin: {final_margin:.3f}")
print(f" Hard negative ratio target: {curriculum_stats['hard_negative_ratio']:.3f}")
print(f" Hard positive ratio target: {curriculum_stats['hard_positive_ratio']:.3f}")
print(f" Negative weight multiplier: {self.config.negative_weight_multiplier:.2f}")
print(f" Triplet weight: {self.config.triplet_weight:.2f}")
print(f" FP penalty weight: {self.config.false_positive_penalty_weight:.2f}")
debug_printed = True
# Forward pass to get embeddings first
with torch.amp.autocast(device_type=self.device.type):
a_emb, p_emb, n_emb = model(anchors, positives, negatives)
# Compute distances and weights BEFORE loss computation
with torch.no_grad():
d_ap = F.pairwise_distance(a_emb, p_emb).cpu().numpy()
d_an = F.pairwise_distance(a_emb, n_emb).cpu().numpy()
# Get precision-focused weights
pos_weights, neg_weights = metrics.compute_precision_focused_weights(
d_ap, d_an,
negative_weight_multiplier=self.config.negative_weight_multiplier
)
pos_weights = pos_weights.to(self.device)
neg_weights = neg_weights.to(self.device)
# Track false positives/negatives
fp_mask = d_an < model.distance_threshold
fn_mask = d_ap > model.distance_threshold
batch_fp_count = fp_mask.sum()
batch_fn_count = fn_mask.sum()
metrics.false_positive_count += batch_fp_count
metrics.false_negative_count += batch_fn_count
# Prepare distance weights for loss
distance_weights = {
'positive_weights': pos_weights,
'negative_weights': neg_weights
}
# Now compute loss with weights
with torch.amp.autocast(device_type=self.device.type):
all_embeddings = torch.cat([a_emb, p_emb, n_emb], dim=0)
all_labels = torch.cat([anchor_ids, anchor_ids, negative_ids], dim=0)
# Compute loss with triplet component and distance weights
batch_loss = model.compute_loss(
all_embeddings, all_labels,
anchors=a_emb, positives=p_emb, negatives=n_emb,
distance_weights=distance_weights
)
# Gradient accumulation
loss = batch_loss / self.config.grad_accum_steps
scaler.scale(loss).backward()
if (step + 1) % self.config.grad_accum_steps == 0 or (step + 1) == len(train_loader):
scaler.unscale_(optimizer)
torch.nn.utils.clip_grad_norm_(model.parameters(), max_norm=1.0)
scaler.step(optimizer)
scaler.update()
optimizer.zero_grad(set_to_none=True)
self.global_step += 1
# Update metrics
metrics.losses.append(batch_loss.item())
metrics.genuine_distances.extend(d_ap.tolist())
metrics.forged_distances.extend(d_an.tolist())
# Use enhanced mining with difficulty parameters
metrics.update_mining_stats(d_ap, d_an, final_margin, curriculum_stats)
# Store learning rates
for i, group in enumerate(optimizer.param_groups):
metrics.learning_rates[f"lr_{group.get('name', i)}"] = group['lr']
# Enhanced progress bar with precision focus
sep = np.mean(d_an) - np.mean(d_ap)
actual_forgery_ratio = forgery_batch_count / (forgery_batch_count + genuine_batch_count) if (forgery_batch_count + genuine_batch_count) > 0 else 0
# Get current mining stats
mining_pcts = metrics.get_mining_percentages()
pbar.set_postfix({
"loss": f"{batch_loss.item():.3f}",
"h_neg%": f"{mining_pcts.get('neg_mining_hard_pct', 0):.0f}",
"h_pos%": f"{mining_pcts.get('pos_mining_hard_pct', 0):.0f}",
"d_sep": f"{sep:.3f}",
"FP": f"{batch_fp_count}",
"FN": f"{batch_fn_count}",
"margin": f"{final_margin:.3f}"
})
# Periodic logging
if self.global_step % self.config.log_frequency == 0:
enhanced_stats = {
**curriculum_stats,
**mining_pcts,
"actual_forgery_ratio": actual_forgery_ratio,
"batch_false_positives": int(batch_fp_count),
"batch_false_negatives": int(batch_fn_count),
"final_margin": final_margin,
"epoch_progress": epoch_progress
}
self._log_training_step(metrics, enhanced_stats, self.global_step)
# Memory cleanup
del anchors, positives, negatives, a_emb, p_emb, n_emb
torch.cuda.empty_cache()
# End-of-epoch mining summary
mining_pcts = metrics.get_mining_percentages()
print(f"\n[Epoch {epoch} Mining Summary]")
print(f" Hard Negatives: {mining_pcts.get('neg_mining_hard_pct', 0):.1f}% | Semi: {mining_pcts.get('neg_mining_semi_pct', 0):.1f}% | Easy: {mining_pcts.get('neg_mining_easy_pct', 0):.1f}%")
print(f" Hard Positives: {mining_pcts.get('pos_mining_hard_pct', 0):.1f}% | Semi: {mining_pcts.get('pos_mining_semi_pct', 0):.1f}% | Easy: {mining_pcts.get('pos_mining_easy_pct', 0):.1f}%")
print(f" Overall Hard Ratios - Positives: {mining_pcts.get('hard_positive_ratio', 0):.1f}% | Negatives: {mining_pcts.get('hard_negative_ratio', 0):.1f}%")
print(f" False Positive Rate: {mining_pcts.get('false_positive_rate', 0):.1f}% | False Negative Rate: {mining_pcts.get('false_negative_rate', 0):.1f}%")
if "adaptive_separation" in mining_pcts:
print(f" Adaptive separation: {mining_pcts['adaptive_separation']:.3f} | Overlap: {mining_pcts['adaptive_overlap']:.3f}")
return metrics
def validate_epoch(self, model: nn.Module, val_loader: DataLoader,
epoch: int) -> Tuple[float, float, Dict[str, float]]:
"""Validate for one epoch."""
model.eval()
val_distances = []
val_labels = []
val_embeddings = []
val_person_ids = []
val_loss_total = 0.0
with torch.no_grad():
pbar = tqdm(val_loader, desc=f"[Val] Epoch {epoch}")
for img1, img2, labels, id1, id2 in pbar:
# Move to device
img1 = img1.to(self.device, non_blocking=True)
img2 = img2.to(self.device, non_blocking=True)
labels = labels.to(self.device, non_blocking=True)
id1 = id1.to(self.device, non_blocking=True)
id2 = id2.to(self.device, non_blocking=True)
# Forward pass
emb1, emb2 = model(img1, img2)
distances = F.pairwise_distance(emb1, emb2)
# Compute validation loss
val_loss = self._compute_validation_loss(emb1, emb2, labels, id1, id2, model.criterion)
val_loss_total += val_loss.item()
# Collect results
val_distances.extend(distances.cpu().numpy())
val_labels.extend(labels.cpu().numpy())
val_embeddings.append(emb1.cpu().numpy())
val_embeddings.append(emb2.cpu().numpy())
val_person_ids.extend(id1.cpu().numpy())
val_person_ids.extend(id2.cpu().numpy())
# Update progress
pos_mask = labels == 1
neg_mask = labels == 0
pos_dist = distances[pos_mask].mean().item() if pos_mask.any() else 0.0
neg_dist = distances[neg_mask].mean().item() if neg_mask.any() else 0.0
pbar.set_postfix({
"loss": f"{val_loss.item():.4f}",
"d_pos": f"{pos_dist:.3f}",
"d_neg": f"{neg_dist:.3f}",
"sep": f"{neg_dist - pos_dist:.3f}"
})
# Memory cleanup
del img1, img2, emb1, emb2
torch.cuda.empty_cache()
# Process results
val_distances = np.array(val_distances)
val_labels = np.array(val_labels)
val_embeddings = np.concatenate(val_embeddings)
val_person_ids = np.array(val_person_ids)
avg_val_loss = val_loss_total / len(val_loader)
# Compute metrics
threshold, eer, metrics_dict = self._compute_validation_metrics(
val_distances, val_labels, avg_val_loss
)
# Update model threshold
model.distance_threshold = threshold
return threshold, eer, {
"metrics": metrics_dict,
"embeddings": val_embeddings,
"labels": np.repeat(val_labels, 2),
"person_ids": val_person_ids,
"distances": np.repeat(val_distances, 2)
}
def _compute_validation_loss(self, emb1: torch.Tensor, emb2: torch.Tensor,
binary_labels: torch.Tensor, person_ids1: torch.Tensor,
person_ids2: torch.Tensor, criterion) -> torch.Tensor:
"""Compute validation loss using MultiSimilarityLoss."""
labels1 = person_ids1.clone()
labels2 = person_ids2.clone()
# Handle forged pairs
forged_mask = binary_labels == 0
if forged_mask.any():
max_person_id = torch.max(torch.cat([person_ids1, person_ids2])).item()
labels2[forged_mask] = labels2[forged_mask] + max_person_id + 1
# Handle genuine pairs
genuine_mask = binary_labels == 1
labels2[genuine_mask] = labels1[genuine_mask]
# Combine embeddings and labels
all_embeddings = torch.cat([emb1, emb2], dim=0)
all_labels = torch.cat([labels1, labels2], dim=0)
return criterion(all_embeddings, all_labels)
def _compute_validation_metrics(self, distances: np.ndarray, labels: np.ndarray,
val_loss: float) -> Tuple[float, float, Dict[str, float]]:
"""Compute comprehensive validation metrics with precision focus."""
# Compute EER and threshold
similarity_scores = 1.0 / (distances + 1e-8)
fpr, tpr, thresholds = roc_curve(labels, similarity_scores, pos_label=1)
fnr = 1 - tpr
eer_idx = np.nanargmin(np.abs(fpr - fnr))
eer = fpr[eer_idx]
eer_threshold = 1.0 / thresholds[eer_idx]
# Get precision-optimized threshold
precision_threshold = self._compute_precision_optimized_threshold(distances, labels)
# Use precision-optimized threshold instead of EER threshold
threshold = precision_threshold
# Compute metrics with precision-optimized threshold
predictions = (distances < threshold).astype(int)
precision, recall, f1, _ = precision_recall_fscore_support(
labels, predictions, average='binary', zero_division=0
)
accuracy = (predictions == labels).mean()
roc_auc = auc(fpr, tpr)
# Distance statistics
genuine_dist = np.mean([d for d, l in zip(distances, labels) if l == 1])
forged_dist = np.mean([d for d, l in zip(distances, labels) if l == 0])
separation = forged_dist - genuine_dist
# Confidence scores
confidences = 1.0 / (distances + 1e-8)
conf_genuine = np.mean([c for c, l in zip(confidences, labels) if l == 1])
conf_forged = np.mean([c for c, l in zip(confidences, labels) if l == 0])
metrics_dict = {
"val_loss": val_loss,
"val_EER": eer,
"val_f1": f1,
"val_auc": roc_auc,
"val_accuracy": accuracy,
"val_precision": precision,
"val_recall": recall,
"val_separation": separation,
"val_genuine_dist": genuine_dist,
"val_forged_dist": forged_dist,
"val_genuine_conf": conf_genuine,
"val_forged_conf": conf_forged,
"threshold": threshold,
"eer_threshold": eer_threshold,
"precision_threshold": precision_threshold
}
return threshold, eer, metrics_dict
def _log_training_step(self, metrics: TrainingMetrics, curriculum_stats: Dict, step: int):
"""Log training step metrics."""
if not metrics.losses:
return
try:
# Compute separation metrics
sep_metrics = metrics.compute_separation_metrics()
# Get mining percentages
mining_percentages = metrics.get_mining_percentages()
# Log to MLflow
log_dict = {
"train_loss": np.mean(metrics.losses[-10:]), # Last 10 batches
**sep_metrics,
**mining_percentages,
**curriculum_stats,
**metrics.learning_rates
}
mlflow.log_metrics(log_dict, step=step)
except Exception as e:
print(f"Warning: Failed to log training step metrics: {e}")
def _log_epoch_metrics(self, train_metrics: TrainingMetrics, val_metrics: Dict, epoch: int):
"""Log comprehensive epoch metrics."""
try:
# Training metrics
train_sep = train_metrics.compute_separation_metrics()
train_mining = train_metrics.get_mining_percentages()
log_dict = {
"epoch": epoch,
"train_loss_epoch": np.mean(train_metrics.losses),
**train_sep,
**train_mining,
**val_metrics["metrics"],
**train_metrics.learning_rates
}
mlflow.log_metrics(log_dict, step=epoch)
# Log key metrics to console
self.logger.info(f"Epoch {epoch}/{self.config.max_epochs} Summary:")
self.logger.info(f" Train Loss: {log_dict['train_loss_epoch']:.4f}")
self.logger.info(f" Val EER: {log_dict['val_EER']:.4f}")
self.logger.info(f" Val F1: {log_dict['val_f1']:.4f}")
self.logger.info(f" Separation: {log_dict['separation']:.4f}")
except Exception as e:
self.logger.error(f"Failed to log epoch metrics: {e}")
# Log minimal metrics as fallback
mlflow.log_metrics({
"epoch": epoch,
"train_loss_epoch": np.mean(train_metrics.losses) if train_metrics.losses else 0.0,
**val_metrics["metrics"]
}, step=epoch)
def _save_checkpoint(self, model: nn.Module, optimizer: torch.optim.Optimizer,
scheduler: Any, scaler: torch.amp.GradScaler, epoch: int,
threshold: float, eer: float, checkpoint_dir: str, is_best: bool = False):
"""Save model checkpoint."""
checkpoint = {
"epoch": epoch,
"model_state_dict": model.state_dict(),
"optimizer_state_dict": optimizer.state_dict(),
"scheduler_state_dict": scheduler.state_dict(),
"scaler_state_dict": scaler.state_dict(),
"prediction_threshold": threshold,
"best_eer": self.best_eer,
"eer": eer,
"config": asdict(self.config)
}
# Save regular checkpoint
if epoch % self.config.save_frequency == 0:
torch.save(checkpoint, os.path.join(checkpoint_dir, f"epoch_{epoch}.pth"))
# Save best checkpoint
if is_best:
torch.save(checkpoint, os.path.join(checkpoint_dir, "best_model.pth"))
self.logger.info(f"New best model saved with EER: {eer:.4f}")
def _create_visualizations(self, val_results: Dict, epoch: int, figures_dir: str):
"""Create comprehensive visualizations."""
if epoch % self.config.visualize_frequency != 0:
return
# Distance distribution plot
self._plot_distance_distribution(
val_results["distances"][:len(val_results["distances"])//2],
val_results["labels"][:len(val_results["labels"])//2],
epoch, figures_dir
)
# t-SNE embedding visualization
self._plot_tsne_embeddings(
val_results["embeddings"],
val_results["labels"],
val_results["person_ids"],
val_results["distances"],
epoch, figures_dir
)
def _plot_distance_distribution(self, distances: np.ndarray, labels: np.ndarray,
epoch: int, figures_dir: str):
"""Plot distance distribution."""
genuine_dists = distances[labels == 1]
forged_dists = distances[labels == 0]
plt.figure(figsize=(12, 8))
plt.hist(genuine_dists, bins=50, alpha=0.6, color='blue',
label=f'Genuine (μ={np.mean(genuine_dists):.4f}±{np.std(genuine_dists):.4f})')
plt.hist(forged_dists, bins=50, alpha=0.6, color='red',
label=f'Forged (μ={np.mean(forged_dists):.4f}±{np.std(forged_dists):.4f})')
separation = np.mean(forged_dists) - np.mean(genuine_dists)
plt.axvline(np.mean(genuine_dists), color='blue', linestyle='--', alpha=0.7)
plt.axvline(np.mean(forged_dists), color='red', linestyle='--', alpha=0.7)
plt.title(f'Distance Distribution - Epoch {epoch}\nSeparation: {separation:.4f}', fontsize=14)
plt.xlabel('Embedding Distance', fontsize=12)
plt.ylabel('Frequency', fontsize=12)
plt.legend(fontsize=12)
plt.grid(alpha=0.3)
plt.savefig(os.path.join(figures_dir, f"distance_dist_epoch_{epoch}.png"),
dpi=150, bbox_inches='tight')
plt.close()
def _plot_tsne_embeddings(self, embeddings: np.ndarray, labels: np.ndarray,
person_ids: np.ndarray, distances: np.ndarray,
epoch: int, figures_dir: str, n_samples: int = 3000):
"""Create comprehensive t-SNE visualization."""
# Sample for computational efficiency
if len(embeddings) > n_samples:
indices = np.random.choice(len(embeddings), n_samples, replace=False)
embeddings = embeddings[indices]
labels = labels[indices]
person_ids = person_ids[indices]
distances = distances[indices]
# Compute t-SNE
tsne = TSNE(n_components=2, random_state=42, perplexity=min(30, len(embeddings)-1))
embeddings_2d = tsne.fit_transform(embeddings)
fig, axes = plt.subplots(1, 3, figsize=(20, 6))
# 1. Genuine vs Forged
for label_val, color, name in [(0, 'red', 'Forged'), (1, 'blue', 'Genuine')]:
mask = labels == label_val
if mask.any():
axes[0].scatter(embeddings_2d[mask, 0], embeddings_2d[mask, 1],
c=color, label=name, alpha=0.6, s=20)
axes[0].set_title(f'Genuine vs Forged - Epoch {epoch}')
axes[0].legend()
axes[0].grid(alpha=0.3)
# 2. Person clusters
unique_ids = np.unique(person_ids)
colors = plt.cm.tab20(np.linspace(0, 1, min(20, len(unique_ids))))
# Show top 15 most frequent IDs
id_counts = {pid: np.sum(person_ids == pid) for pid in unique_ids}
top_ids = sorted(id_counts.items(), key=lambda x: x[1], reverse=True)[:15]
for idx, (pid, count) in enumerate(top_ids):
mask = person_ids == pid
color = colors[idx % len(colors)]
# Plot the cluster points
axes[1].scatter(embeddings_2d[mask, 0], embeddings_2d[mask, 1],
c=[color], label=f'ID {pid} (n={count})', alpha=0.7, s=25)
# Compute the centroid (mean position) of the points in this cluster
centroid = np.mean(embeddings_2d[mask], axis=0)
# Add the person ID text at the centroid
axes[1].text(centroid[0], centroid[1], f'ID {pid}', fontsize=10, color='black', alpha=0.8, ha='center')
# Plot others in gray
other_mask = ~np.isin(person_ids, [pid for pid, _ in top_ids])
if other_mask.any():
axes[1].scatter(embeddings_2d[other_mask, 0], embeddings_2d[other_mask, 1],
c='gray', label='Others', alpha=0.3, s=15)
axes[1].set_title(f'Person Clusters - Epoch {epoch}')
axes[1].legend(bbox_to_anchor=(1.05, 1), loc='upper left', fontsize=8)
axes[1].grid(alpha=0.3)
# 3. Distance-based coloring
scatter = axes[2].scatter(embeddings_2d[:, 0], embeddings_2d[:, 1],
c=distances, cmap='viridis', alpha=0.7, s=20)
plt.colorbar(scatter, ax=axes[2], label='Distance')
axes[2].set_title(f'Distance Visualization - Epoch {epoch}')
axes[2].grid(alpha=0.3)
plt.tight_layout()
plt.savefig(os.path.join(figures_dir, f"tsne_epoch_{epoch}.png"),
dpi=150, bbox_inches='tight')
plt.close()
def train(self):
"""Main training loop."""
torch.backends.cudnn.benchmark = True
self.logger.info(f"Starting training on device: {self.device}")
# Prepare components
train_dataset, val_dataset = self._prepare_datasets()
model, optimizer, scheduler = self._setup_model_and_optimizer()
scaler = torch.amp.GradScaler(self.device.type, enabled=(self.device.type == "cuda"))
# MLflow setup
with self.mlflow_manager.start_run(run_id=self.config.run_id):
run_id = mlflow.active_run().info.run_id
self.mlflow_manager.log_config(self.config)
# Setup checkpoints
checkpoint_dir, figures_dir = self._setup_checkpoint_management(run_id)
# Load checkpoint if specified
start_epoch = self._load_checkpoint(model, optimizer, scheduler, scaler)
# Data loaders
val_loader = DataLoader(
val_dataset, batch_size=self.config.batch_size, shuffle=False,
num_workers=4, pin_memory=True, prefetch_factor=2
)
# Training loop
for epoch in range(start_epoch, self.config.max_epochs + 1):
self.current_epoch = epoch
# Update curriculum
train_dataset.set_epoch(epoch)
train_loader = DataLoader(
train_dataset, batch_size=self.config.batch_size, shuffle=True,
num_workers=4, pin_memory=True, persistent_workers=True, prefetch_factor=2
)
# Training phase
train_metrics = self.train_epoch(model, train_loader, optimizer, scaler, epoch)
# Validation phase
threshold, eer, val_results = self.validate_epoch(model, val_loader, epoch)
# Logging
self._log_epoch_metrics(train_metrics, val_results, epoch)
# Visualizations
self._create_visualizations(val_results, epoch, figures_dir)
# Model checkpoint management
is_best = eer < self.best_eer
if is_best:
self.best_eer = eer
self.patience_counter = 0
else:
self.patience_counter += 1
self._save_checkpoint(
model, optimizer, scheduler, scaler, epoch,
threshold, eer, checkpoint_dir, is_best
)
# Early stopping
if self.patience_counter >= self.config.patience:
self.logger.info(f"Early stopping after {self.config.patience} epochs without improvement")
break
# Learning rate scheduling
if self.config.lr_scheduler == "cosine":
scheduler.step()
else:
scheduler.step(eer)
# Memory cleanup
gc.collect()
torch.cuda.empty_cache()
# Final logging
mlflow.log_metric("final_best_eer", self.best_eer)
self.logger.info(f"Training completed. Best EER: {self.best_eer:.4f}")
# ----------------------------
# Image Processing Utilities
# ----------------------------
def estimate_background_color_pil(image: Image.Image, border_width: int = 10,
method: str = "median") -> np.ndarray:
"""Estimate background color from image borders."""
if image.mode != 'RGB':
image = image.convert('RGB')
np_img = np.array(image)
h, w, _ = np_img.shape
# Extract border pixels
top = np_img[:border_width, :, :].reshape(-1, 3)
bottom = np_img[-border_width:, :, :].reshape(-1, 3)
left = np_img[:, :border_width, :].reshape(-1, 3)
right = np_img[:, -border_width:, :].reshape(-1, 3)
all_border_pixels = np.concatenate([top, bottom, left, right], axis=0)
if method == "mean":
return np.mean(all_border_pixels, axis=0).astype(np.uint8)
else:
return np.median(all_border_pixels, axis=0).astype(np.uint8)
def replace_background_with_white(image_name: str, folder_img: str,
tolerance: int = 40, method: str = "median",
remove_bg: bool = False) -> Image.Image:
"""Replace background with white based on border color estimation."""
image_path = os.path.join(folder_img, image_name)
image = Image.open(image_path).convert("RGB")
if not remove_bg:
return image
np_img = np.array(image)
bg_color = estimate_background_color_pil(image, method=method)
# Create mask for background pixels
diff = np.abs(np_img.astype(np.int32) - bg_color.astype(np.int32))
mask = np.all(diff < tolerance, axis=2)
# Replace background with white
result = np_img.copy()
result[mask] = [255, 255, 255]
return Image.fromarray(result)
# ----------------------------
# Main Execution
# ----------------------------
def main():
"""Main execution function with aggressive curriculum."""
# Test distance ranges first
print("\n[INFO] Testing distance ranges for margin calibration...")
dummy_emb1 = F.normalize(torch.randn(1000, 128), p=2, dim=1)
dummy_emb2 = F.normalize(torch.randn(1000, 128), p=2, dim=1)
dummy_distances = F.pairwise_distance(dummy_emb1, dummy_emb2).numpy()
print(f"Random embeddings: mean={dummy_distances.mean():.3f}, std={dummy_distances.std():.3f}")
print(f"Expected margin range: {dummy_distances.std() * 0.5:.3f} - {dummy_distances.std() * 1.5:.3f}")
# Aggressive curriculum configuration
CONFIG.model_name = "resnet34"
CONFIG.embedding_dim = 128
CONFIG.max_epochs = 20 # Shorter with aggressive curriculum
CONFIG.head_lr = 2e-3 # Higher for faster adaptation
CONFIG.backbone_lr = 1e-4
CONFIG.curriculum_strategy = "progressive"
# AGGRESSIVE SETTINGS
CONFIG.initial_hard_ratio = 0.4 # Start much higher
CONFIG.final_hard_ratio = 0.85 # Target very high
CONFIG.curriculum_warmup_epochs = 1 # Very short warmup
CONFIG.batch_size = 256 # Smaller batches for more frequent updates
CONFIG.grad_accum_steps = 8 # Smaller accumulation
CONFIG.tracking_uri = "http://127.0.0.1:5555"
#CONFIG.run_id = "aa58e3a1f3314351bc1dd2b82ab156ad"
#CONFIG.last_epoch_weights = "../../model/models_checkpoints/aa58e3a1f3314351bc1dd2b82ab156ad/best_model.pth"
trainer = SignatureTrainer(CONFIG)
trainer.train()
if __name__ == "__main__":
main()