Files
lidar_rendu/lidar_pipeline/visualizations.py
Jacquin Antoine d334892880 Improve visualizations: adaptive scales, revert z-score to std normalization
- MSRM/TPI/roughness/anomalies: revert z-score (x-mean)/std to std normalization x/std
  to preserve contrast and visibility of linear features (paths, ditches, trenches)
- MSRM: adaptive scales based on resolution, archaeological weight combination
- TPI: extend from 2 to 4 scales (3m/15m/50m/200m) with weighted combination
- Hillshade: 8 directions instead of 4, altitude 35° instead of 30°
- LRM: adaptive sigma based on resolution
- Openness: doubled radius (100m instead of 50m)
- Roughness: multi-scale (3m fine + 15m broad) instead of single 5x5 window
- Anomalies: uses MSRM multi-scale relief instead of single LRM 15m
- Wavelet: 8 adaptive scales, std normalization, archaeological weights
- Remove svf (Sky-View Factor) and local_dominance visualizations
- Add AVIF format support (default), quality 98
- Add multi-resolution support (-r 0.5,0.2)
- Improve Ctrl+C handling for immediate process termination
- Update rendering.py descriptions for all modified visualizations

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
2026-05-14 23:12:08 +02:00

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"""Terrain visualization functions for LiDAR archaeological analysis.
Each function takes (dem_file, basename, vis_dir, resolution) as explicit
parameters and returns the path to the output GeoTIFF file, or None on error.
When a SharedDEM object is provided via the `shared` parameter, pre-computed
data (gradient, NaN mask, LRM) is reused across visualizations to avoid
redundant I/O and computation.
"""
import logging
import time
import warnings
from pathlib import Path
import numpy as np
import rasterio
from scipy.ndimage import generic_filter
from scipy.stats import binned_statistic_2d
from .gpu import HAS_GPU, to_gpu, to_cpu, xp_gaussian_filter, xp_uniform_filter, xp_minimum_filter, xp_maximum_filter, gpu_cleanup
logger = logging.getLogger("lidar")
# Use CuPy array module when available
if HAS_GPU:
import cupy as cp
xp = cp
else:
xp = np
class SharedDEM:
"""Pre-computed DEM data shared across all visualizations.
Reads the DEM once and lazily computes on first access:
- NaN mask and filled DEM (avoids 20+ calls to _fill_nans)
- Gradient components (shared by hillshade, slope, aspect, curvature)
- LRM at 15m kernel (shared by lrm + anomalies)
Attributes are computed lazily on first access to avoid computing
data that is never used (e.g. LRM when only hillshade needs generation).
"""
def __init__(self, dem_file, resolution):
dem_np, transform, crs = _read_dem(dem_file)
self.dem_file = dem_file
self.resolution = resolution
self.transform = transform
self.crs = crs
self.nan_mask = np.isnan(dem_np)
self.dem_np = dem_np.astype(np.float32)
# Lazy caches — computed on first access
self._filled = None
self._gradient = None # (dy, dx, slope_rad, slope_deg, aspect)
self._lrm_15 = None
# GPU lazy caches
self._filled_gpu = None
self._dem_gpu = None
@property
def filled(self):
"""Filled DEM (NaN interpolated) — computed lazily."""
if self._filled is None:
logger.debug(" → Calcul filled DEM (interpolation NaN)...")
self._filled, _ = _fill_nans(self.dem_np)
return self._filled
@property
def dy(self):
self._ensure_gradient()
return self._gradient[0]
@property
def dx(self):
self._ensure_gradient()
return self._gradient[1]
@property
def slope_rad(self):
self._ensure_gradient()
return self._gradient[2]
@property
def slope_deg(self):
self._ensure_gradient()
return self._gradient[3]
@property
def aspect(self):
self._ensure_gradient()
return self._gradient[4]
@property
def lrm_15(self):
"""LRM at 15m kernel — computed lazily."""
if self._lrm_15 is None:
logger.debug(" → Calcul LRM 15m...")
sigma_15 = 15.0 / self.resolution
local_mean_15 = _filter_nanaware_from_filled(self, xp_gaussian_filter, sigma=sigma_15)
self._lrm_15 = self.dem_np - local_mean_15
self._lrm_15[self.nan_mask] = np.nan
return self._lrm_15
def _ensure_gradient(self):
"""Compute gradient components lazily on first access."""
if self._gradient is None:
logger.debug(" → Calcul gradient...")
dy = np.gradient(self.filled, self.resolution, axis=0)
dx = np.gradient(self.filled, self.resolution, axis=1)
slope_rad = np.arctan(np.sqrt(dx**2 + dy**2))
slope_deg = np.degrees(slope_rad)
aspect = np.mod(np.degrees(np.arctan2(dy, dx)), 360)
self._gradient = (dy, dx, slope_rad, slope_deg, aspect)
@property
def filled_gpu(self):
"""Lazy GPU copy of the filled DEM."""
if self._filled_gpu is None and HAS_GPU:
self._filled_gpu = to_gpu(self.filled)
return self._filled_gpu
@property
def dem_gpu(self):
"""Lazy GPU copy of the DEM."""
if self._dem_gpu is None and HAS_GPU:
self._dem_gpu = to_gpu(self.dem_np)
return self._dem_gpu
def _filter_nanaware_from_filled(shared, filter_func, *args, **kwargs):
"""Apply filter on pre-filled DEM data (skips expensive _fill_nans).
Uses the SharedDEM.filled array directly, then restores NaN mask.
If GPU is available, uses the lazy GPU copy to avoid CPU↔GPU transfers.
"""
if HAS_GPU and shared.filled_gpu is not None:
filled_gpu = to_gpu(shared.filled)
result_gpu = filter_func(filled_gpu, *args, **kwargs)
result = to_cpu(result_gpu)
gpu_cleanup()
else:
result = filter_func(shared.filled, *args, **kwargs)
result[shared.nan_mask] = np.nan
return result
def _save_tif(output_path, data, transform, crs, dtype='float32', count=1, nodata=None, nan_mask=None):
"""Helper to save a 2D or 3D array as GeoTIFF.
Args:
nan_mask: Optional boolean mask (True=NaN) to apply before saving.
Restores NaN zones in gradient-derived products that were
computed on the filled DEM.
"""
if nan_mask is not None:
data = np.array(data, dtype=dtype, copy=True)
data[nan_mask] = np.nan
# Auto-detect nodata for float types with NaN
if nodata is None and dtype.startswith('float') and np.any(np.isnan(data)):
nodata = float('nan')
if data.ndim == 2:
height, width = data.shape
with rasterio.open(
output_path, 'w', driver='GTiff',
height=height, width=width, count=count,
dtype=dtype, crs=crs, transform=transform,
compress='deflate', nodata=nodata
) as dst:
dst.write(data.astype(dtype), 1)
elif data.ndim == 3:
bands, height, width = data.shape
with rasterio.open(
output_path, 'w', driver='GTiff',
height=height, width=width, count=bands,
dtype=dtype, crs=crs, transform=transform,
compress='deflate', nodata=nodata
) as dst:
for i in range(bands):
dst.write(data[i].astype(dtype), i + 1)
def _read_dem(dem_file):
"""Read DEM file and return (data, transform, crs)."""
with rasterio.open(dem_file) as src:
return src.read(1), src.transform, src.crs
def _fill_nans(arr):
"""Fill NaN values using nearest-neighbor interpolation.
Returns (filled_array, nan_mask) so the caller can restore NaN after filtering.
"""
from scipy.interpolate import NearestNDInterpolator
nan_mask = np.isnan(arr)
if not np.any(nan_mask):
return arr, nan_mask
valid = ~nan_mask
y_coords, x_coords = np.where(valid)
if len(y_coords) == 0:
return np.zeros_like(arr), nan_mask
z_values = arr[valid]
interp = NearestNDInterpolator(
np.column_stack((y_coords, x_coords)), z_values
)
y_missing, x_missing = np.where(nan_mask)
filled = arr.copy()
filled[y_missing, x_missing] = interp(y_missing, x_missing)
return filled, nan_mask
def _filter_nanaware(arr, filter_func, *args, use_gpu=True, **kwargs):
"""Apply a filter to an array while preserving NaN zones.
1. Fill NaN with nearest-neighbor interpolation
2. Apply the filter
3. Restore original NaN mask on the result
Args:
arr: Input array (numpy or cupy).
filter_func: Function that takes (array, *args, **kwargs) and returns filtered array.
use_gpu: If True, apply filter on GPU (send filled array to GPU first).
Returns:
Filtered array with original NaN positions preserved.
"""
is_gpu_arr = HAS_GPU and isinstance(arr, cp.ndarray)
arr_np = to_cpu(arr) if is_gpu_arr else arr
filled, nan_mask = _fill_nans(arr_np)
if use_gpu and HAS_GPU:
filled_gpu = to_gpu(filled)
result_gpu = filter_func(filled_gpu, *args, **kwargs)
result = to_cpu(result_gpu)
else:
result = filter_func(filled, *args, **kwargs)
result[nan_mask] = np.nan
return result
# ============================================================
# Core terrain visualizations
# ============================================================
def generate_hillshade(dem_file, basename, vis_dir, resolution, shared=None):
"""Generate multi-directional hillshade with contrast enhancement — GPU if available.
Combines 8-direction hillshade with slope shading for balanced illumination.
Applies percentile normalization and gamma correction to restore
contrast lost by averaging multiple azimuths.
"""
gpu_tag = " [GPU]" if HAS_GPU else ""
logger.info(f" → Hillshade multidirectionnel{gpu_tag}...")
t0 = time.time()
output = vis_dir / f"{basename}_hillshade_multi.tif"
try:
if shared:
transform = shared.transform
crs = shared.crs
dem = to_gpu(shared.dem_np)
dy = to_gpu(shared.dy) if HAS_GPU else shared.dy
dx = to_gpu(shared.dx) if HAS_GPU else shared.dx
slope = to_gpu(shared.slope_rad) if HAS_GPU else shared.slope_rad
aspect = xp.arctan2(dy, dx)
sin_slope = xp.sin(slope)
cos_slope = xp.cos(slope)
else:
dem_np, transform, crs = _read_dem(dem_file)
dem = to_gpu(dem_np)
dy, dx = xp.gradient(dem)
slope = xp.arctan(xp.sqrt(dx**2 + dy**2))
aspect = xp.arctan2(dy, dx)
sin_slope = xp.sin(slope)
cos_slope = xp.cos(slope)
# 8 azimuths for balanced illumination (eliminates directional bias)
azimuts = [0, 45, 90, 135, 180, 225, 270, 315]
altitude = 35 # Higher altitude for better micro-relief detection
hillshades = []
alt_rad = xp.radians(xp.array(altitude))
sin_alt = xp.sin(alt_rad)
cos_alt = xp.cos(alt_rad)
for az in azimuts:
az_rad = xp.radians(xp.array(az))
hs = sin_alt * sin_slope + cos_alt * cos_slope * xp.cos(az_rad - aspect)
hillshades.append(xp.clip(hs, 0, 1))
combined_hillshade = xp.mean(xp.array(hillshades), axis=0)
slope_shaded = cos_slope
combined = 0.7 * combined_hillshade + 0.3 * slope_shaded
# Contrast enhancement: percentile stretch + gamma
combined_np = to_cpu(combined)
nan_mask = shared.nan_mask if shared else np.isnan(to_cpu(dem_np) if HAS_GPU else dem_np)
valid = combined_np[~nan_mask]
if len(valid) > 0:
p2, p98 = np.percentile(valid, 2), np.percentile(valid, 98)
if p98 - p2 > 0.01:
combined_np = np.clip((combined_np - p2) / (p98 - p2), 0, 1)
# Gamma correction to enhance shadows
gamma = 0.8
combined_np = np.power(combined_np, gamma)
_save_tif(output, combined_np.astype(np.float32), transform, crs, nan_mask=nan_mask)
logger.info(f" ✓ Hillshade terminé ({time.time()-t0:.1f}s){gpu_tag}")
return output
except Exception as e:
logger.error(f" ✗ Erreur hillshade: {e}", exc_info=True)
return None
def generate_slope(dem_file, basename, vis_dir, resolution, shared=None):
"""Generate slope map (degrees) — GPU if available."""
gpu_tag = " [GPU]" if HAS_GPU else ""
logger.info(f" → Pente (Slope){gpu_tag}...")
t0 = time.time()
output = vis_dir / f"{basename}_slope.tif"
try:
if shared:
transform = shared.transform
crs = shared.crs
slope = shared.slope_deg
nan_mask = shared.nan_mask
if HAS_GPU:
slope = to_gpu(slope)
else:
dem_np, transform, crs = _read_dem(dem_file)
dem = to_gpu(dem_np)
dy, dx = xp.gradient(dem)
slope = xp.arctan(xp.sqrt(dx**2 + dy**2)) * 180 / xp.pi
nan_mask = np.isnan(dem_np)
_save_tif(output, to_cpu(slope) if HAS_GPU else slope, transform, crs, nan_mask=nan_mask)
logger.info(f" ✓ Pente terminée ({time.time()-t0:.1f}s){gpu_tag}")
return output
except Exception as e:
logger.error(f" ✗ Erreur slope: {e}", exc_info=True)
return None
def generate_aspect(dem_file, basename, vis_dir, resolution, shared=None):
"""Generate aspect (slope orientation) map — GPU if available."""
gpu_tag = " [GPU]" if HAS_GPU else ""
logger.info(f" → Aspect (Orientation){gpu_tag}...")
t0 = time.time()
output = vis_dir / f"{basename}_aspect.tif"
try:
if shared:
transform = shared.transform
crs = shared.crs
aspect = shared.aspect
nan_mask = shared.nan_mask
if HAS_GPU:
aspect = to_gpu(aspect)
else:
dem_np, transform, crs = _read_dem(dem_file)
dem = to_gpu(dem_np)
dy, dx = xp.gradient(dem)
aspect = xp.arctan2(dy, dx) * 180 / xp.pi
aspect = xp.mod(aspect, 360)
nan_mask = np.isnan(dem_np)
_save_tif(output, to_cpu(aspect) if HAS_GPU else aspect, transform, crs, nan_mask=nan_mask)
logger.info(f" ✓ Aspect terminé ({time.time()-t0:.1f}s){gpu_tag}")
return output
except Exception as e:
logger.error(f" ✗ Erreur aspect: {e}", exc_info=True)
return None
def generate_curvature(dem_file, basename, vis_dir, resolution, shared=None):
"""Generate curvature (terrain concavity/convexity) map — GPU if available."""
gpu_tag = " [GPU]" if HAS_GPU else ""
logger.info(f" → Courbure (Curvature){gpu_tag}...")
t0 = time.time()
output = vis_dir / f"{basename}_curvature.tif"
try:
if shared:
transform = shared.transform
crs = shared.crs
dx = shared.dx
dy = shared.dy
nan_mask = shared.nan_mask
if HAS_GPU:
dx = to_gpu(dx)
dy = to_gpu(dy)
else:
dem_np, transform, crs = _read_dem(dem_file)
dem = to_gpu(dem_np)
dy, dx = xp.gradient(dem)
nan_mask = np.isnan(dem_np)
d2z_dx2 = xp.gradient(dx, axis=1)
d2z_dy2 = xp.gradient(dy, axis=0)
curvature = (d2z_dx2 + d2z_dy2) / 2
_save_tif(output, to_cpu(curvature), transform, crs, nan_mask=nan_mask)
logger.info(f" ✓ Courbure terminée ({time.time()-t0:.1f}s){gpu_tag}")
return output
except Exception as e:
logger.error(f" ✗ Erreur curvature: {e}", exc_info=True)
return None
# ============================================================
# GPU-accelerated visualizations
# ============================================================
def generate_lrm(dem_file, basename, vis_dir, resolution, shared=None):
"""Local Relief Model - deviation from local mean (GPU if available).
Kernel sigma adapts to resolution: finer kernel at higher resolution
to capture micro-relief details. At 0.5m/px: 15m, at 0.2m/px: ~5m.
"""
gpu_tag = " [GPU]" if HAS_GPU else ""
logger.info(f" → Local Relief Model{gpu_tag}...")
t0 = time.time()
output = vis_dir / f"{basename}_lrm.tif"
try:
if shared:
transform = shared.transform
crs = shared.crs
lrm = shared.lrm_15.copy()
else:
dem_np, transform, crs = _read_dem(dem_file)
nan_mask = np.isnan(dem_np)
# Adapt sigma to resolution: standard 15m at 0.5m, finer at higher res
sigma_m = max(5.0, 15.0 * 0.5 / resolution)
logger.info(f" LRM sigma={sigma_m:.1f}m (résolution {resolution}m/px)")
local_mean = _filter_nanaware(dem_np, xp_gaussian_filter, sigma=sigma_m / resolution)
lrm = dem_np - local_mean
lrm[nan_mask] = np.nan
_save_tif(output, lrm.astype(np.float32), transform, crs)
logger.info(f" ✓ LRM terminé ({time.time()-t0:.1f}s){gpu_tag}")
return output
except Exception as e:
logger.error(f" ✗ Erreur LRM: {e}", exc_info=True)
return None
def generate_svf(dem_file, basename, vis_dir, resolution, shared=None):
"""Sky-View Factor - ray-tracing on 16 azimuths (GPU if available).
For each pixel, trace rays in N directions, find the max horizon
angle in each direction, then SVF = (1/N) * sum(cos²(horizon_angle)).
Valleys/crevices have low SVF (obstructed sky), ridges/peaks have high SVF.
"""
gpu_tag = " [GPU]" if HAS_GPU else ""
logger.info(f" → Sky-View Factor (ray-tracing){gpu_tag}...")
t0 = time.time()
output = vis_dir / f"{basename}_svf.tif"
try:
if shared:
transform = shared.transform
crs = shared.crs
dem_np = shared.dem_np
rows, cols = dem_np.shape
res = resolution
dem = to_gpu(shared.filled) if HAS_GPU else shared.filled
nan_mask = shared.nan_mask
else:
dem_np, transform, crs = _read_dem(dem_file)
rows, cols = dem_np.shape
res = resolution
nan_mask = np.isnan(dem_np)
filled, _ = _fill_nans(dem_np)
dem = to_gpu(filled) if HAS_GPU else filled
n_dirs = 16
angles = np.linspace(0, 2 * np.pi, n_dirs, endpoint=False)
dx_dir = np.cos(angles)
dy_dir = np.sin(angles)
max_dist = int(100 / res)
padded = xp.pad(dem, max_dist, mode='constant', constant_values=xp.nan)
svf = xp.zeros_like(dem)
for d_idx in range(n_dirs):
ddx, ddy = dx_dir[d_idx], dy_dir[d_idx]
horizon = xp.zeros_like(dem)
# Pre-compute all valid steps for this direction
valid_steps = []
for step in range(1, max_dist + 1):
px = int(round(ddx * step))
py = int(round(ddy * step))
dist_m = np.sqrt((ddx * step * res) ** 2 + (ddy * step * res) ** 2)
if dist_m < res * 0.5:
continue
valid_steps.append((step, px, py, dist_m))
# Batch all shifts into a single array for vectorized max computation
for step, px, py, dist_m in valid_steps:
elev_diff = padded[max_dist + py:max_dist + py + rows,
max_dist + px:max_dist + px + cols] - dem
angle = xp.arctan2(elev_diff, dist_m)
horizon = xp.where(xp.isnan(angle), horizon,
xp.maximum(horizon, xp.nan_to_num(angle, nan=0)))
svf += xp.cos(xp.pi / 2 - horizon) ** 2
svf /= n_dirs
svf_np = to_cpu(svf).astype(np.float32)
svf_np[nan_mask] = np.nan
_save_tif(output, svf_np, transform, crs)
logger.info(f" ✓ SVF terminé ({time.time()-t0:.1f}s){gpu_tag}")
return output
except Exception as e:
logger.error(f" ✗ Erreur SVF: {e}", exc_info=True)
return None
def generate_openness(dem_file, basename, vis_dir, resolution, positive=True, shared=None):
"""Positive/Negative Openness - true zenith/nadir angle computation (GPU if available).
For each pixel, in 8 directions (N, NE, E, SE, S, SW, W, NW):
- Positive openness: max zenith angle (angle from vertical to highest visible terrain)
- Negative openness: max nadir angle (angle from vertical down to lowest terrain)
Result is averaged across all 8 directions.
Ray radius adapts to resolution: 100m for better detection of large enclosures.
"""
name = "positive_openness" if positive else "negative_openness"
gpu_tag = " [GPU]" if HAS_GPU else ""
logger.info(f"{name.replace('_', ' ').title()} (ray-tracing){gpu_tag}...")
t0 = time.time()
output = vis_dir / f"{basename}_{name}.tif"
try:
if shared:
transform = shared.transform
crs = shared.crs
dem_np = shared.dem_np
rows, cols = dem_np.shape
res = resolution
dem = to_gpu(shared.filled) if HAS_GPU else shared.filled
nan_mask = shared.nan_mask
else:
dem_np, transform, crs = _read_dem(dem_file)
rows, cols = dem_np.shape
res = resolution
nan_mask = np.isnan(dem_np)
filled, _ = _fill_nans(dem_np)
dem = to_gpu(filled) if HAS_GPU else filled
n_dirs = 8
angles = np.linspace(0, 2 * np.pi, n_dirs, endpoint=False)
dx_dir = np.cos(angles)
dy_dir = np.sin(angles)
max_dist = int(100 / res)
padded = xp.pad(dem, max_dist, mode='constant', constant_values=xp.nan)
openness_sum = xp.zeros_like(dem)
for d_idx in range(n_dirs):
ddx, ddy = dx_dir[d_idx], dy_dir[d_idx]
max_angle = xp.zeros_like(dem)
for step in range(1, max_dist + 1):
px = int(round(ddx * step))
py = int(round(ddy * step))
dist_m = np.sqrt((ddx * step * res) ** 2 + (ddy * step * res) ** 2)
if dist_m < res * 0.5:
continue
elev_diff = padded[max_dist + py:max_dist + py + rows,
max_dist + px:max_dist + px + cols] - dem
if positive:
angle = xp.arctan2(xp.maximum(elev_diff, 0), dist_m)
else:
angle = xp.arctan2(xp.maximum(-elev_diff, 0), dist_m)
max_angle = xp.where(xp.isnan(angle), max_angle,
xp.maximum(max_angle, xp.nan_to_num(angle, nan=0)))
openness_sum += max_angle
openness_result = to_cpu(xp.degrees(openness_sum / n_dirs)).astype(np.float32)
openness_result[nan_mask] = np.nan
_save_tif(output, openness_result, transform, crs)
logger.info(f"{name} terminé ({time.time()-t0:.1f}s){gpu_tag}")
return output
except Exception as e:
logger.error(f" ✗ Erreur openness: {e}", exc_info=True)
return None
def generate_local_dominance(dem_file, basename, vis_dir, resolution, shared=None,
radius=15, pmin=2, pmax=98):
"""Local Dominance — proportion of neighborhood below center point.
LD = (dem - local_min) / (local_max - local_min + epsilon)
High values = locally dominant (peak, ridge)
Low values = locally recessed (valley, pit)
Uses minimum/maximum filters on the filled DEM, then restores NaN mask.
Complements openness by measuring local height position rather than angular extent.
"""
gpu_tag = " [GPU]" if HAS_GPU else ""
logger.info(f" → Dominance Locale (rayon {radius}m){gpu_tag}...")
t0 = time.time()
output = vis_dir / f"{basename}_local_dominance.tif"
try:
if shared:
transform = shared.transform
crs = shared.crs
nan_mask = shared.nan_mask
dem_np = shared.dem_np
else:
dem_np, transform, crs = _read_dem(dem_file)
nan_mask = np.isnan(dem_np)
radius_px = max(1, int(radius / resolution))
if radius_px % 2 == 0:
radius_px += 1
local_min = _filter_nanaware_from_filled(
shared, xp_minimum_filter, size=radius_px
) if shared else _filter_nanaware(
dem_np, xp_minimum_filter, size=radius_px
)
local_max_data = _filter_nanaware_from_filled(
shared, xp_maximum_filter, size=radius_px
) if shared else _filter_nanaware(
dem_np, xp_maximum_filter, size=radius_px
)
# Local dominance ratio
epsilon = 0.01 # Avoid division by zero on flat terrain
local_range = local_max_data - local_min + epsilon
dominance = (dem_np - local_min) / local_range
dominance = np.clip(dominance, 0, 1)
dominance[nan_mask] = np.nan
_save_tif(output, dominance.astype(np.float32), transform, crs, nan_mask=nan_mask)
logger.info(f" ✓ Dominance Locale terminée ({time.time()-t0:.1f}s){gpu_tag}")
return output
except Exception as e:
logger.error(f" ✗ Erreur local_dominance: {e}", exc_info=True)
return None
def generate_mslrm(dem_file, basename, vis_dir, resolution, shared=None):
"""Multi-Scale Relief Model (MSRM) - LRM at adaptive scales combined (GPU if available).
Scales adapt to resolution. Std normalization per scale.
Weighted combination favoring archaeologically relevant scales (5-25m).
"""
gpu_tag = " [GPU]" if HAS_GPU else ""
logger.info(f" → Multi-Scale Relief Model (MSRM){gpu_tag}...")
t0 = time.time()
output = vis_dir / f"{basename}_mslrm.tif"
try:
if shared:
transform = shared.transform
crs = shared.crs
dem_np = shared.dem_np
nan_mask = shared.nan_mask
else:
dem_np, transform, crs = _read_dem(dem_file)
nan_mask = np.isnan(dem_np)
# Adaptive scales: finer at higher resolution
min_scale = max(2.0, resolution * 4)
candidate_scales = [2, 5, 10, 20, 50, 100, 200]
sigmas = [s for s in candidate_scales if s >= min_scale]
# Archaeological weights: favor 5-25m range (ditches, enclosures, tumulus)
scale_weights = {
2: 0.8, 5: 2.0, 10: 1.8, 20: 1.5, 50: 1.0, 100: 0.6, 200: 0.4,
}
weights = np.array([scale_weights.get(s, 1.0) for s in sigmas])
logger.info(f" MSRM échelles: {sigmas}m")
lrm_stack = []
for sigma in sigmas:
sigma_px = sigma / resolution
if shared:
local_mean = _filter_nanaware_from_filled(shared, xp_gaussian_filter, sigma=sigma_px)
else:
local_mean = _filter_nanaware(dem_np, xp_gaussian_filter, sigma=sigma_px)
lrm = dem_np - local_mean
lrm[nan_mask] = np.nan
# Std normalization: x / std — preserves sign and contrast better than z-score
valid_lrm = lrm[~nan_mask]
lrm_std = max(np.nanstd(valid_lrm), 0.01) if len(valid_lrm) > 0 else 0.01
lrm = lrm / lrm_std
lrm_stack.append(lrm.astype(np.float32))
# Weighted combination
lrm_array = np.array(lrm_stack)
weights_3d = weights[:, np.newaxis, np.newaxis]
with np.errstate(invalid='ignore', divide='ignore'):
with warnings.catch_warnings():
warnings.filterwarnings('ignore', message='Mean of empty slice')
mslrm = np.sqrt(np.nansum((lrm_array ** 2) * weights_3d, axis=0) / np.sum(weights))
mslrm[nan_mask] = np.nan
_save_tif(output, mslrm.astype(np.float32), transform, crs)
logger.info(f" ✓ MSRM terminé ({time.time()-t0:.1f}s){gpu_tag}")
return output
except Exception as e:
logger.error(f" ✗ Erreur MSRM: {e}", exc_info=True)
return None
def generate_tpi(dem_file, basename, vis_dir, resolution, shared=None):
"""Multi-Scale Topographic Position Index (GPU if available).
TPI = elevation - mean(neighborhood).
Computed at 4 scales with std normalization and weighted combination.
Weights favor fine and medium scales (archaeologically relevant).
"""
gpu_tag = " [GPU]" if HAS_GPU else ""
logger.info(f" → TPI multi-échelle{gpu_tag}...")
t0 = time.time()
output = vis_dir / f"{basename}_tpi.tif"
try:
if shared:
transform = shared.transform
crs = shared.crs
dem_np = shared.dem_np
nan_mask = shared.nan_mask
else:
dem_np, transform, crs = _read_dem(dem_file)
nan_mask = np.isnan(dem_np)
# 4 scales: fine (3m), medium (15m), broad (50m), landscape (200m)
scales_m = [3, 15, 50, 200]
weights = [1.5, 2.0, 1.2, 0.5] # Favor medium scales (ditches, enclosures)
tpi_stack = []
for scale_m, weight in zip(scales_m, weights):
size = max(3, int(scale_m / resolution))
if size % 2 == 0:
size += 1
if shared:
local_mean = _filter_nanaware_from_filled(shared, xp_uniform_filter, size=size)
else:
local_mean = _filter_nanaware(dem_np, xp_uniform_filter, size=size)
tpi = dem_np - local_mean
tpi[nan_mask] = np.nan
# Std normalization — preserves sign and contrast better than z-score
valid = tpi[~nan_mask]
tpi_std = max(np.nanstd(valid), 0.01) if len(valid) > 0 else 0.01
tpi = tpi / tpi_std
tpi_stack.append(tpi.astype(np.float32))
# Weighted combination
tpi_array = np.array(tpi_stack)
weights_3d = np.array(weights)[:, np.newaxis, np.newaxis]
with np.errstate(invalid='ignore', divide='ignore'):
with warnings.catch_warnings():
warnings.filterwarnings('ignore', message='Mean of empty slice')
tpi_combined = np.nansum(tpi_array * weights_3d, axis=0) / np.sum(weights)
tpi_combined[nan_mask] = np.nan
_save_tif(output, tpi_combined.astype(np.float32), transform, crs)
logger.info(f" ✓ TPI terminé ({time.time()-t0:.1f}s){gpu_tag}")
return output
except Exception as e:
logger.error(f" ✗ Erreur TPI: {e}", exc_info=True)
return None
# ============================================================
# SAILORE
# ============================================================
def generate_sailore(dem_file, basename, vis_dir, resolution, shared=None):
"""SAILORE - Self-Adaptive Improved Local Relief Model (GPU if available).
Kernel size adapts to local slope: flat areas get larger kernels,
steep areas get smaller kernels. Scales adapt to resolution.
"""
gpu_tag = " [GPU]" if HAS_GPU else ""
logger.info(f" → SAILORE (LRM adaptatif){gpu_tag}...")
t0 = time.time()
output = vis_dir / f"{basename}_sailore.tif"
try:
if shared:
transform = shared.transform
crs = shared.crs
dem_np = shared.dem_np
nan_mask = shared.nan_mask
slope_deg = shared.slope_deg
else:
dem_np, transform, crs = _read_dem(dem_file)
nan_mask = np.isnan(dem_np)
gy, gx = np.gradient(dem_np, resolution)
slope = np.arctan(np.sqrt(gx**2 + gy**2))
slope_deg = np.degrees(slope)
slope_deg[nan_mask] = np.nan
# Adaptive scales: finer at higher resolution
sigma_min_m = max(1.0, 2.0 * 0.5 / resolution) # 2m at 0.5, ~5m at 0.2
sigma_mid_m = max(5.0, 13.5 * 0.5 / resolution) # 13.5m at 0.5, ~33m at 0.2
sigma_max_m = max(5.0, 25.0 * 0.5 / resolution) # 25m at 0.5, ~62m at 0.2
sigma_min = sigma_min_m / resolution
sigma_max = sigma_max_m / resolution
sigma_mid = (sigma_min + sigma_max) / 2
slope_norm = np.clip(slope_deg / 30.0, 0, 1)
if shared:
lrm_fine = dem_np - _filter_nanaware_from_filled(shared, xp_gaussian_filter, sigma=sigma_min)
else:
lrm_fine = dem_np - _filter_nanaware(dem_np, xp_gaussian_filter, sigma=sigma_min)
lrm_fine[nan_mask] = np.nan
if shared:
lrm_medium = dem_np - _filter_nanaware_from_filled(shared, xp_gaussian_filter, sigma=(sigma_min + sigma_max) / 2)
else:
lrm_medium = dem_np - _filter_nanaware(dem_np, xp_gaussian_filter, sigma=(sigma_min + sigma_max) / 2)
lrm_medium[nan_mask] = np.nan
if shared:
lrm_coarse = dem_np - _filter_nanaware_from_filled(shared, xp_gaussian_filter, sigma=sigma_max)
else:
lrm_coarse = dem_np - _filter_nanaware(dem_np, xp_gaussian_filter, sigma=sigma_max)
lrm_coarse[nan_mask] = np.nan
w_fine = slope_norm
w_medium = 1 - 2 * np.abs(slope_norm - 0.5)
w_coarse = 1 - slope_norm
w_total = w_fine + w_medium + w_coarse
w_total[w_total == 0] = 1
sailore = (w_fine * lrm_fine + w_medium * lrm_medium + w_coarse * lrm_coarse) / w_total
sailore[nan_mask] = np.nan
_save_tif(output, sailore.astype(np.float32), transform, crs)
logger.info(f" ✓ SAILORE terminé ({time.time()-t0:.1f}s){gpu_tag}")
return output
except Exception as e:
logger.error(f" ✗ Erreur SAILORE: {e}", exc_info=True)
return None
# ============================================================
# Roughness
# ============================================================
def generate_roughness(dem_file, basename, vis_dir, resolution, shared=None):
"""Surface roughness - multi-scale standard deviation (GPU-accelerated).
Combines fine (3m) and broad (15m) roughness for better detection
of archaeological features at multiple scales.
"""
gpu_tag = " [GPU]" if HAS_GPU else ""
logger.info(f" → Rugosité de surface{gpu_tag}...")
t0 = time.time()
output = vis_dir / f"{basename}_roughness.tif"
try:
if shared:
transform = shared.transform
crs = shared.crs
dem_np = shared.dem_np
nan_mask = shared.nan_mask
else:
dem_np, transform, crs = _read_dem(dem_file)
nan_mask = np.isnan(dem_np)
# Fine roughness (3m window)
fine_size = max(3, int(3 / resolution))
if fine_size % 2 == 0:
fine_size += 1
if shared:
fine_mean = _filter_nanaware_from_filled(shared, xp_uniform_filter, size=fine_size)
fine_mean_sq = _filter_nanaware(shared.filled.astype(np.float64)**2, xp_uniform_filter, size=fine_size)
fine_mean_sq[shared.nan_mask] = np.nan
else:
fine_mean = _filter_nanaware(dem_np.astype(np.float64), xp_uniform_filter, size=fine_size)
fine_mean_sq = _filter_nanaware(dem_np.astype(np.float64)**2, xp_uniform_filter, size=fine_size)
roughness_fine = np.sqrt(np.maximum(fine_mean_sq - fine_mean * fine_mean, 0))
roughness_fine[nan_mask] = np.nan
# Broad roughness (15m window)
broad_size = max(3, int(15 / resolution))
if broad_size % 2 == 0:
broad_size += 1
if shared:
broad_mean = _filter_nanaware_from_filled(shared, xp_uniform_filter, size=broad_size)
broad_mean_sq = _filter_nanaware(shared.filled.astype(np.float64)**2, xp_uniform_filter, size=broad_size)
broad_mean_sq[shared.nan_mask] = np.nan
else:
broad_mean = _filter_nanaware(dem_np.astype(np.float64), xp_uniform_filter, size=broad_size)
broad_mean_sq = _filter_nanaware(dem_np.astype(np.float64)**2, xp_uniform_filter, size=broad_size)
roughness_broad = np.sqrt(np.maximum(broad_mean_sq - broad_mean * broad_mean, 0))
roughness_broad[nan_mask] = np.nan
# Std normalization per scale then weighted combination
fine_valid = roughness_fine[~nan_mask]
broad_valid = roughness_broad[~nan_mask]
fine_std = max(np.nanstd(fine_valid), 0.01) if len(fine_valid) > 0 else 0.01
broad_std = max(np.nanstd(broad_valid), 0.01) if len(broad_valid) > 0 else 0.01
roughness = 0.7 * roughness_fine / fine_std + 0.3 * roughness_broad / broad_std
roughness[nan_mask] = np.nan
roughness = to_cpu(roughness)
_save_tif(output, roughness, transform, crs)
logger.info(f" ✓ Rugosité terminée ({time.time()-t0:.1f}s){gpu_tag}")
return output
except Exception as e:
logger.error(f" ✗ Erreur rugosité: {e}", exc_info=True)
return None
# ============================================================
# Anomalies
# ============================================================
def generate_anomalies(dem_file, basename, vis_dir, resolution, shared=None):
"""Statistical anomaly detection - std-normalized multi-scale relief + Local Moran's I — GPU if available.
Uses MSRM (multi-scale LRM) instead of single-scale LRM for better detection
of anomalies at all scales.
"""
gpu_tag = " [GPU]" if HAS_GPU else ""
logger.info(f" → Détection anomalies statistiques{gpu_tag}...")
t0 = time.time()
output = vis_dir / f"{basename}_anomalies.tif"
try:
if shared:
transform = shared.transform
crs = shared.crs
dem_np = shared.dem_np
nan_mask = shared.nan_mask
else:
dem_np, transform, crs = _read_dem(dem_file)
nan_mask = np.isnan(dem_np)
# Multi-scale LRM: compute MSRM-like combined relief
min_scale = max(2.0, resolution * 4)
candidate_scales = [2, 5, 10, 20, 50, 100]
sigmas = [s for s in candidate_scales if s >= min_scale]
lrm_stack = []
for sigma in sigmas:
sigma_px = sigma / resolution
if shared:
local_mean = _filter_nanaware_from_filled(shared, xp_gaussian_filter, sigma=sigma_px)
else:
local_mean = _filter_nanaware(dem_np, xp_gaussian_filter, sigma=sigma_px)
lrm = dem_np - local_mean
lrm[nan_mask] = np.nan
# Std normalization — preserves contrast better than z-score
valid_lrm = lrm[~nan_mask]
lrm_std = max(np.nanstd(valid_lrm), 0.01) if len(valid_lrm) > 0 else 0.01
lrm_norm = lrm / lrm_std
else:
lrm_norm = lrm
lrm_stack.append(lrm_norm.astype(np.float32))
# Weighted RMS combination (favor 5-25m scales)
scale_weights = {2: 0.8, 5: 2.0, 10: 1.8, 20: 1.5, 50: 1.0, 100: 0.6}
weights = np.array([scale_weights.get(s, 1.0) for s in sigmas])
lrm_array = np.array(lrm_stack)
weights_3d = weights[:, np.newaxis, np.newaxis]
with np.errstate(invalid='ignore', divide='ignore'):
with warnings.catch_warnings():
warnings.filterwarnings('ignore', message='Mean of empty slice')
msrm = np.sqrt(np.nansum((lrm_array ** 2) * weights_3d, axis=0) / np.sum(weights))
msrm[nan_mask] = np.nan
# Std normalization of MSRM — preserves contrast better than z-score
valid_msrm = msrm[~nan_mask]
msrm_std = max(np.nanstd(valid_msrm), 0.01) if len(valid_msrm) > 0 else 0.01
z_score = msrm / msrm_std
# Local Moran's I for spatial clustering
window = max(3, int(10 / resolution))
if window % 2 == 0:
window += 1
if shared:
local_mean_z = _filter_nanaware_from_filled(shared, xp_uniform_filter, size=window)
else:
local_mean_z = _filter_nanaware(z_score, xp_uniform_filter, size=window)
z_mean_global = np.nanmean(z_score[~nan_mask]) if np.any(~nan_mask) else 0
z_std_global = max(np.nanstd(z_score[~nan_mask]), 0.01) if np.any(~nan_mask) else 0.01
morans_i = z_score * (local_mean_z - z_mean_global) / z_std_global
anomaly_score = np.abs(z_score) * np.sign(morans_i)
anomaly_score[nan_mask] = np.nan
_save_tif(output, anomaly_score.astype(np.float32), transform, crs)
logger.info(f" ✓ Anomalies terminé ({time.time()-t0:.1f}s){gpu_tag}")
return output
except Exception as e:
logger.error(f" ✗ Erreur anomalies: {e}", exc_info=True)
return None
# ============================================================
# Wavelet
# ============================================================
def generate_wavelet(dem_file, basename, vis_dir, resolution, shared=None):
"""Mexican Hat wavelet multi-scale analysis (GPU if available).
CWT 2D at multiple scales adapted to resolution.
- At 0.5m/px: [1, 2, 5, 10, 20, 50, 100]m
- At 0.2m/px: [0.5, 1, 2, 5, 10, 20, 50, 100]m
- Higher resolution = more fine scales available
Uses std normalization per scale and weighted combination
with emphasis on archaeologically relevant scales (2-50m).
"""
gpu_tag = " [GPU]" if HAS_GPU else ""
logger.info(f" → Ondelette Mexican Hat multi-échelle{gpu_tag}...")
t0 = time.time()
output = vis_dir / f"{basename}_wavelet.tif"
try:
if shared:
transform = shared.transform
crs = shared.crs
dem_np = shared.dem_np
nan_mask = shared.nan_mask
filled = shared.filled.astype(np.float64)
else:
dem_np, transform, crs = _read_dem(dem_file)
nan_mask = np.isnan(dem_np)
filled, _ = _fill_nans(dem_np.astype(np.float64))
# Adapt scales to resolution: finer scales available at higher resolution
min_scale = max(resolution * 2, 1.0)
candidate_scales = [0.5, 1, 2, 5, 10, 20, 50, 100]
scales = [s for s in candidate_scales if s >= min_scale]
# Weights favor archaeological scales (2-50m: ditches, enclosures, tumulus)
scale_weights = {
0.5: 0.6, # Fine texture
1.0: 0.8, # Micro-relief
2.0: 1.5, # Small ditches, paths — key scale
5.0: 2.0, # Fossés, small enclosures — key archaeological scale
10.0: 1.8, # Medium structures
20.0: 1.5, # Large enclosures, tumulus
50.0: 1.0, # Very large enclosures
100.0: 0.6, # Landscape-level features
}
weights = np.array([scale_weights.get(s, 1.0) for s in scales])
logger.info(f" Échelles CWT: {scales}m (résolution {resolution}m/px)")
wavelet_stack = []
for scale_m in scales:
sigma_px = scale_m / resolution
if HAS_GPU:
from cupyx.scipy.ndimage import gaussian_laplace as gpu_gaussian_laplace
response = -gpu_gaussian_laplace(to_gpu(filled), sigma=sigma_px)
response = to_cpu(response)
else:
from scipy.ndimage import gaussian_laplace
response = -gaussian_laplace(filled, sigma=sigma_px)
response[nan_mask] = np.nan
# Std normalization: scale by standard deviation to make scales comparable
valid = response[~nan_mask]
std_val = max(np.nanstd(valid), 0.01) if len(valid) > 0 else 0.01
response = response / std_val
wavelet_stack.append(response)
# Weighted RMS: sqrt(sum(w * x²) / sum(w))
# Preserves contrast at key archaeological scales
stack = np.array(wavelet_stack)
weights_3d = weights[:, np.newaxis, np.newaxis]
with np.errstate(invalid='ignore', divide='ignore'):
with warnings.catch_warnings():
warnings.filterwarnings('ignore', message='Mean of empty slice')
combined = np.sqrt(np.nansum((stack ** 2) * weights_3d, axis=0) / np.sum(weights))
combined[nan_mask] = np.nan
_save_tif(output, combined.astype(np.float32), transform, crs)
logger.info(f" ✓ Ondelette terminée ({time.time()-t0:.1f}s){gpu_tag}")
return output
except Exception as e:
logger.error(f" ✗ Erreur ondelette: {e}", exc_info=True)
return None
# ============================================================
# Flow accumulation
# ============================================================
def _d8_accumulate_numba(flow_dir, nodata_mask, rows, cols):
"""JIT-compiled D8 flow accumulation loop.
Uses numba for ~100x speedup over pure Python loop.
Falls back to pure Python if numba is unavailable.
"""
try:
from numba import njit
@njit(cache=True)
def _accumulate(flow_dir, nodata_mask, rows, cols):
dx8 = np.array([1, 1, 0, -1, -1, -1, 0, 1], dtype=np.int8)
dy8 = np.array([0, 1, 1, 1, 0, -1, -1, -1], dtype=np.int8)
flow_acc = np.ones((rows, cols), dtype=np.float32)
# Sort cells by elevation (high to low) — walk downhill
# We use the fact that flow_dir already encodes steepest descent
# Process from highest to lowest elevation
for r in range(rows):
for c in range(cols):
if nodata_mask[r, c]:
flow_acc[r, c] = 0.0
continue
# Iterative accumulation: process cells in top-down order
# Multiple passes until convergence
for _pass in range(10):
changed = 0
for r in range(rows):
for c in range(cols):
if nodata_mask[r, c]:
continue
d = flow_dir[r, c]
if d < 0:
continue
nr = r + dy8[d]
nc = c + dx8[d]
if 0 <= nr < rows and 0 <= nc < cols and not nodata_mask[nr, nc]:
old_acc = flow_acc[nr, nc]
flow_acc[nr, nc] += flow_acc[r, c]
if flow_acc[nr, nc] != old_acc:
changed += 1
if changed == 0:
break
return flow_acc
return _accumulate(flow_dir, nodata_mask, rows, cols)
except ImportError:
# Fallback: pure Python
return None
def _priority_flood(dem, nodata_mask):
"""Priority-flood algorithm for sink filling (Wang & Liu 2006).
O(n log n) compared to 50 iterations of minimum_filter.
Fills pits so water can flow downhill.
"""
import heapq
rows, cols = dem.shape
filled = dem.copy()
closed = nodata_mask.copy()
open_queue = []
# Initialize border cells
for r in range(rows):
for c in [0, cols - 1]:
if not closed[r, c]:
heapq.heappush(open_queue, (filled[r, c], r, c))
closed[r, c] = True
for c in range(1, cols - 1):
for r in [0, rows - 1]:
if not closed[r, c]:
heapq.heappush(open_queue, (filled[r, c], r, c))
closed[r, c] = True
dx8 = [1, 1, 0, -1, -1, -1, 0, 1]
dy8 = [0, 1, 1, 1, 0, -1, -1, -1]
while open_queue:
elev, r, c = heapq.heappop(open_queue)
for d in range(8):
nr, nc = r + dy8[d], c + dx8[d]
if 0 <= nr < rows and 0 <= nc < cols and not closed[nr, nc]:
if filled[nr, nc] < elev:
filled[nr, nc] = elev # Fill the pit
closed[nr, nc] = True
heapq.heappush(open_queue, (filled[nr, nc], nr, nc))
return filled
def generate_flow(dem_file, basename, vis_dir, resolution, shared=None):
"""Flow accumulation using D8 algorithm — priority-flood sink filling, accumulation via numba."""
gpu_tag = " [GPU]" if HAS_GPU else ""
logger.info(f" → Accumulation de flux D8{gpu_tag}...")
t0 = time.time()
output = vis_dir / f"{basename}_flow.tif"
try:
if shared:
transform = shared.transform
crs = shared.crs
dem_np = shared.dem_np
nodata_mask = shared.nan_mask
else:
dem_np, transform, crs = _read_dem(dem_file)
nodata_mask = np.isnan(dem_np)
rows, cols = dem_np.shape
# Sink filling — priority-flood (O(n log n), faster than 50× minimum_filter)
dem_filled_np = _priority_flood(dem_np, nodata_mask)
# D8 slope — vectorized
dx8 = np.array([1, 1, 0, -1, -1, -1, 0, 1], dtype=np.int32)
dy8 = np.array([0, 1, 1, 1, 0, -1, -1, -1], dtype=np.int32)
dist8 = np.array([1.0, np.sqrt(2), 1.0, np.sqrt(2), 1.0, np.sqrt(2), 1.0, np.sqrt(2)])
flow_dir = np.full((rows, cols), -1, dtype=np.int8)
max_slope = np.zeros((rows, cols), dtype=np.float64)
padded = np.pad(dem_filled_np, 1, mode='constant',
constant_values=np.nanmax(dem_filled_np[~np.isnan(dem_filled_np)]) + 10000)
for d in range(8):
nx = 1 + dx8[d]
ny = 1 + dy8[d]
neighbor_elev = padded[ny:ny + rows, nx:nx + cols]
slope = (dem_filled_np - neighbor_elev) / (dist8[d] * resolution)
slope[nodata_mask] = -1
better = slope > max_slope
flow_dir[better] = d
max_slope[better] = slope[better]
# D8 accumulation — try numba first, fallback to Python
result = _d8_accumulate_numba(flow_dir, nodata_mask.astype(np.bool_), rows, cols)
if result is not None:
flow_acc = result
logger.info(f" Accumulation D8 via numba")
else:
# Pure Python fallback (slow for large DEMs)
logger.info(f" Accumulation D8 via Python (installez numba pour accélérer)")
flat_dem = dem_filled_np[~nodata_mask].flatten()
valid_indices = np.where(~nodata_mask.flatten())[0]
sort_order = valid_indices[np.argsort(-flat_dem)]
flow_acc = np.ones((rows, cols), dtype=np.float32)
flow_acc[nodata_mask] = 0
for idx in sort_order:
r, c = divmod(idx, cols)
d = flow_dir[r, c]
if d < 0:
continue
nr, nc = r + dy8[d], c + dx8[d]
if 0 <= nr < rows and 0 <= nc < cols and not nodata_mask[nr, nc]:
flow_acc[nr, nc] += flow_acc[r, c]
flow_log = np.log1p(flow_acc)
_save_tif(output, flow_log, transform, crs)
logger.info(f" ✓ Flux terminé ({time.time()-t0:.1f}s){gpu_tag}")
return output
except Exception as e:
logger.error(f" ✗ Erreur flux: {e}", exc_info=True)
return None