Pipeline LiDAR complet: 9 visualisations + classification sémantique automatique

- Correction bug geojson dans process_lidar.py
- Semantic classifier fonctionnel avec K-Means
- 9 visualisations JPEG selon état de l'art 2024-2025
- Statistiques de classification sémantique exportées en JSON
- Nettoyage automatique des fichiers temporaires

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
This commit is contained in:
Jacquin Antoine
2026-05-08 23:37:14 +02:00
parent 2cc5b2a5f3
commit e642cde7bc
4 changed files with 517 additions and 18 deletions

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#!/usr/bin/env python3
"""
Module de Classification Sémantique Simplifié pour LiDAR Archéologique
Approche robuste avec K-Means pour classification automatique
"""
import numpy as np
import rasterio
from rasterio.transform import from_bounds
from sklearn.cluster import KMeans
from scipy import ndimage
import json
from pathlib import Path
import matplotlib.pyplot as plt
import matplotlib.colors as mcolors
class ArchaeoSemanticClassifier:
"""Classification sémantique automatique robuste"""
def __init__(self, dtm_file, output_dir):
self.dtm_file = Path(dtm_file)
self.output_dir = Path(output_dir)
self.output_dir.mkdir(parents=True, exist_ok=True)
# Load DTM
with rasterio.open(self.dtm_file) as src:
self.dem = src.read(1)
self.transform = src.transform
self.crs = src.crs
self.height, self.width = self.dem.shape
print(f"✓ Classifieur initialisé (DTM: {self.width}x{self.height})")
def extract_features_simple(self):
"""Extraction simplifiée des caractéristiques"""
print(" → Extraction caractéristiques...")
# Calculate gradients
dy, dx = np.gradient(self.dem)
# Slope
slope = np.arctan(np.sqrt(dx**2 + dy**2)) * 180 / np.pi
# Aspect
aspect = np.arctan2(-dy, dx) * 180 / np.pi
aspect = np.mod(aspect, 360)
# Curvature
dz_dx = np.gradient(dx, axis=1)
dz_dy = np.gradient(dy, axis=0)
curvature = (dz_dx + dz_dy) / 2
# Local Relief
from scipy.ndimage import uniform_filter
local_mean = uniform_filter(self.dem, size=int(15/0.5))
local_relief = self.dem - local_mean
return {
'elevation': self.dem,
'slope': slope,
'aspect': aspect,
'curvature': curvature,
'local_relief': local_relief
}
def classify_kmeans(self, n_clusters=6):
"""Classification K-Means robuste"""
print(" → Classification K-Means...")
features = self.extract_features_simple()
# Normalize each feature to 0-1
normalized_features = {}
for name, data in features.items():
min_val = np.percentile(data, 2)
max_val = np.percentile(data, 98)
normalized = np.clip((data - min_val) / (max_val - min_val + 1e-6), 0, 1)
normalized_features[name] = normalized
# Stack features for clustering
feature_stack = np.stack([
normalized_features['elevation'].flatten(),
normalized_features['slope'].flatten(),
normalized_features['curvature'].flatten(),
normalized_features['local_relief'].flatten()
], axis=1)
# Remove NaN values
valid_mask = ~np.isnan(feature_stack).any(axis=1)
feature_stack = feature_stack[valid_mask]
# K-Means clustering with random_state for reproducibility
kmeans = KMeans(n_clusters=n_clusters, random_state=42, n_init=10, max_iter=300)
labels_flat = kmeans.fit_predict(feature_stack)
# Create full resolution labels
full_labels = np.zeros(self.height * self.width, dtype=int)
full_indices = np.where(valid_mask)[0]
full_labels[full_indices] = labels_flat + 1 # +1 to shift from 0-based
full_labels = full_labels.reshape(self.height, self.width)
# Interpret clusters
self._interpret_clusters(kmeans.cluster_centers_, features)
return full_labels
def _interpret_clusters(self, centers, features):
"""Interprète les clusters selon les centroïdes"""
interpretations = {}
# Centers are in normalized feature space
# Features order: elevation, slope, curvature, local_relief
for i, center in enumerate(centers):
elev = center[0]
slope = center[1]
curve = center[2]
relief = center[3]
# Interpret based on feature values
if relief > 0.7:
category = "ÉLEVÉE (Tumulus possible)"
elif relief < -0.3:
category = "ENFONCÉ (Fossé, cavité)"
elif abs(curve) > 0.5:
if curve > 0:
category = "CONVEX (Bosse, monticule)"
else:
category = "CONCAVE (Creux, dépression)"
elif slope > 0.6:
category = "PENTE FORTE (Talus, mur)"
elif slope < 0.2 and elev < 0.3:
category = "PLAT (Zone plane)"
else:
category = "TOPOGRAPHIE MIXTE"
interpretations[i + 1] = category # +1 because labels are 1-indexed
print(f" Interprétation des {len(centers)} clusters :")
for i, interp in interpretations.items():
print(f" Classe {i}: {interp}")
def generate_semantic_map(self, labels):
"""Génère une carte sémantique colorée"""
print(" → Génération carte sémantique...")
# Create color map for semantic classes
# 0: Background, 1-6: Different semantic classes
colors = {
0: [200, 200, 200], # Gray: Background/Unknown
1: [139, 69, 19], # Brown: Linear/Walls
2: [128, 0, 128], # Purple: Circular/Mounds
3: [255, 140, 0], # Orange: Elevated
4: [0, 200, 255], # Cyan: Depressed
5: [220, 220, 0], # Yellow: Slope
6: [0, 128, 0] # Green: Vegetation/Natural
}
# Create RGB image
rgb = np.zeros((self.height, self.width, 3), dtype=np.uint8)
for class_id, color in colors.items():
mask = labels == class_id
for c in range(3):
rgb[:, :, c][mask] = color[c]
return rgb
def process(self, basename):
"""Pipeline complet de classification sémantique"""
print(f"\n{'='*60}")
print(f" CLASSIFICATION SÉMANTIQUE - {basename}")
print(f"{'='*60}")
# Run K-Means classification
labels = self.classify_kmeans(n_clusters=6)
# Generate semantic map
rgb = self.generate_semantic_map(labels)
# Save semantic classification
output_tif = self.output_dir / f"{basename}_semantic.tif"
with rasterio.open(
output_tif,
'w',
driver='GTiff',
height=self.height,
width=self.width,
count=1,
dtype='uint8',
crs=self.crs,
transform=self.transform,
compress='lzw'
) as dst:
dst.write(labels, 1)
# Save visualization
output_jpg = self.output_dir / f"{basename}_semantic.jpg"
plt.figure(figsize=(16, 12), facecolor='white')
plt.imshow(rgb)
# Create legend
legend_elements = [
plt.Rectangle((0, 0), 1, 1, facecolor=np.array(c)/255, edgecolor='black', label=label)
for label, c in [
("Inconnu/Fond", [200, 200, 200]),
("Linéaire (murs)", [139, 69, 19]),
("Circulaire (tumulus)", [128, 0, 128]),
("Élevé (monticules)", [255, 140, 0]),
("Enfoncé (fossés)", [0, 200, 255]),
("Pente forte (talus)", [220, 220, 0]),
("Naturel", [0, 128, 0])
]
]
plt.legend(handles=legend_elements, loc='upper right', fontsize=11)
plt.title(f"Classification Sémantique LiDAR - {basename}\n",
fontsize=14, fontweight='bold', pad=15)
plt.axis('off')
plt.tight_layout()
plt.savefig(output_jpg, dpi=150, bbox_inches='tight', format='jpg')
plt.close()
# Generate statistics
stats = self._generate_stats(labels, basename)
print(f"\n✓ Classification terminée !")
print(f" • Carte sémantique: {output_tif.name}")
print(f" • Visualisation: {output_jpg.name}")
print(f" • Statistiques: {self.output_dir / f'{basename}_statistics.json'}")
return {
'labels': labels,
'tif': output_tif,
'jpg': output_jpg,
'stats': stats
}
def _generate_stats(self, labels, basename):
"""Génère les statistiques de classification"""
print(" → Génération statistiques...")
total_pixels = labels.size
stats = {}
class_names = {
0: "Inconnu/Fond",
1: "Linéaire",
2: "Circulaire",
3: "Élevée",
4: "Enfoncée",
5: "Pente forte",
6: "Naturel"
}
for class_id in range(7):
count = np.sum(labels == class_id)
percentage = (count / total_pixels) * 100
if count > 0:
stats[class_id] = {
'name': class_names[class_id],
'count': int(count),
'percentage': float(percentage)
}
# Save as JSON
stats_file = self.output_dir / f"{basename}_statistics.json"
with open(stats_file, 'w') as f:
json.dump(stats, f, indent=2, default=lambda x: float(x) if isinstance(x, (np.floating, np.integer)) else x)
# Print summary
print(f"\n 📊 Statistiques :")
for class_id, info in stats.items():
print(f" {info['name']}: {info['count']:.0f} px ({info['percentage']:.1f}%)")
return stats
def main():
import sys
if len(sys.argv) < 2:
print("Usage: python semantic_classifier.py <dtm_file.tif> [output_dir]")
sys.exit(1)
dtm_file = sys.argv[1]
output_dir = sys.argv[2] if len(sys.argv) > 2 else "semantic_output"
classifier = ArchaeoSemanticClassifier(dtm_file, output_dir)
classifier.process(Path(dtm_file).stem)
if __name__ == "__main__":
main()