Files
remove-ai-watermarks/scripts/synthid_periodic_tile_probe.py
T

260 lines
10 KiB
Python

"""Discover and evaluate an exact-geometry periodic residual carrier.
The model folds a high-pass residual modulo a fixed tile, averaging thousands
of spatial repetitions before normalized correlation. It is a positive-only
research signal, not a universal or certified SynthID decoder.
"""
from __future__ import annotations
import json
import logging
from dataclasses import asdict, dataclass
from pathlib import Path
import click
import numpy as np
from synthid_periodic_tile import cyclic_tile_correlations, fold_residual_template, unit_tile
from synthid_pixel_attack import load_rgb
from synthid_research_manifest import artifact_sha256
log = logging.getLogger(__name__)
@dataclass(frozen=True)
class PeriodicTileModel:
"""One exact-geometry normalized periodic-residual template."""
height: int
width: int
tile_height: int
tile_width: int
denoise_sigma: float
template: np.ndarray
expected_norm: float
@dataclass(frozen=True)
class PeriodicTileScore:
"""Normalized tile correlation and support for one image."""
path: str
score: float
active_support: float
row_shift: int
column_shift: int
repeat_count: int
def _load_rgb(path: Path, *, height: int, width: int) -> np.ndarray:
"""Load PATH as exact-geometry uint8 RGB."""
pixels = load_rgb(path)
if pixels.shape != (height, width, 3):
raise ValueError(f"{path}: geometry {pixels.shape[1]}x{pixels.shape[0]} does not match {width}x{height}")
return pixels
def discover_model(
paths: list[Path],
*,
tile_height: int,
tile_width: int,
denoise_sigma: float = 1.0,
) -> PeriodicTileModel:
"""Learn a normalized periodic template from positive PATHS."""
if len(paths) < 3:
raise ValueError("at least three positive images are required")
first_pixels = load_rgb(paths[0])
height, width = first_pixels.shape[:2]
unit_sum = np.zeros((tile_height, tile_width, 3), dtype=np.float64)
norms: list[float] = []
for index, path in enumerate(paths):
folded = fold_residual_template(
first_pixels if index == 0 else _load_rgb(path, height=height, width=width),
tile_height=tile_height,
tile_width=tile_width,
denoise_sigma=denoise_sigma,
)
unit, norm = unit_tile(folded)
unit_sum += unit
norms.append(norm)
template, template_norm = unit_tile(unit_sum / len(paths))
if template_norm == 0.0:
raise ValueError("positive images expose no periodic residual template")
return PeriodicTileModel(
height=height,
width=width,
tile_height=tile_height,
tile_width=tile_width,
denoise_sigma=denoise_sigma,
template=template,
expected_norm=float(np.median(norms)),
)
def score_image(path: Path, model: PeriodicTileModel, *, register: bool = False) -> PeriodicTileScore:
"""Score PATH against MODEL, optionally searching cyclic tile shifts."""
folded = fold_residual_template(
_load_rgb(path, height=model.height, width=model.width),
tile_height=model.tile_height,
tile_width=model.tile_width,
denoise_sigma=model.denoise_sigma,
)
unit, norm = unit_tile(folded)
if register:
correlations = cyclic_tile_correlations(model.template, unit)
row_shift, column_shift = np.unravel_index(int(np.argmax(correlations)), correlations.shape)
score = float(correlations[row_shift, column_shift])
else:
score = float(np.sum(model.template * unit))
row_shift = column_shift = 0
return PeriodicTileScore(
path=str(path),
score=score,
active_support=min(norm / (model.expected_norm + 1e-12), 1.0),
row_shift=row_shift,
column_shift=column_shift,
repeat_count=(model.height // model.tile_height) * (model.width // model.tile_width),
)
def calibrate_threshold(paths: list[Path], model: PeriodicTileModel, *, register: bool = False) -> float:
"""Return the first float above every negative score in PATHS."""
if not paths:
raise ValueError("at least one calibration negative is required")
maximum = max(score_image(path, model, register=register).score for path in paths)
return float(np.nextafter(maximum, np.inf))
def save_model(path: Path, model: PeriodicTileModel) -> None:
"""Save MODEL as a pickle-free numeric artifact without precision loss."""
path.parent.mkdir(parents=True, exist_ok=True)
np.savez_compressed(
path,
format_version=np.asarray(1, dtype=np.int32),
height=np.asarray(model.height, dtype=np.int32),
width=np.asarray(model.width, dtype=np.int32),
tile_height=np.asarray(model.tile_height, dtype=np.int32),
tile_width=np.asarray(model.tile_width, dtype=np.int32),
denoise_sigma=np.asarray(model.denoise_sigma, dtype=np.float64),
template=model.template.astype(np.float64),
expected_norm=np.asarray(model.expected_norm, dtype=np.float64),
)
def load_model(path: Path) -> PeriodicTileModel:
"""Load and validate one numeric periodic-tile model."""
with np.load(path, allow_pickle=False) as artifact:
if int(artifact["format_version"]) != 1:
raise ValueError("unsupported periodic-tile model format version")
model = PeriodicTileModel(
height=int(artifact["height"]),
width=int(artifact["width"]),
tile_height=int(artifact["tile_height"]),
tile_width=int(artifact["tile_width"]),
denoise_sigma=float(artifact["denoise_sigma"]),
template=np.asarray(artifact["template"], dtype=np.float64),
expected_norm=float(artifact["expected_norm"]),
)
if model.height < 1 or model.width < 1 or model.tile_height < 1 or model.tile_width < 1:
raise ValueError("invalid periodic-tile geometry")
if model.height % model.tile_height or model.width % model.tile_width:
raise ValueError("image geometry is not divisible by periodic-tile geometry")
if model.template.shape != (model.tile_height, model.tile_width, 3):
raise ValueError("invalid periodic-tile template shape")
if not np.all(np.isfinite(model.template)) or not np.isclose(np.linalg.norm(model.template), 1.0):
raise ValueError("invalid periodic-tile template")
if not np.isfinite(model.denoise_sigma) or model.denoise_sigma <= 0.0:
raise ValueError("invalid periodic-tile denoise sigma")
if not np.isfinite(model.expected_norm) or model.expected_norm <= 0.0:
raise ValueError("invalid periodic-tile expected norm")
return model
@click.group()
def main() -> None:
"""Discover and evaluate an exact-geometry periodic carrier."""
logging.basicConfig(level=logging.INFO, format="%(message)s")
@main.command()
@click.argument("positives", nargs=-1, required=True, type=click.Path(exists=True, dir_okay=False, path_type=Path))
@click.option("--tile-height", type=click.IntRange(min=1), required=True)
@click.option("--tile-width", type=click.IntRange(min=1), required=True)
@click.option("--denoise-sigma", type=click.FloatRange(min=0.0, min_open=True), default=1.0, show_default=True)
@click.option("--model-out", type=click.Path(dir_okay=False, path_type=Path), required=True)
def discover(
positives: tuple[Path, ...],
tile_height: int,
tile_width: int,
denoise_sigma: float,
model_out: Path,
) -> None:
"""Learn a periodic tile from exact-geometry POSITIVES."""
save_model(
model_out,
discover_model(
list(positives),
tile_height=tile_height,
tile_width=tile_width,
denoise_sigma=denoise_sigma,
),
)
log.info("Wrote periodic-tile model: %s", model_out)
@main.command()
@click.argument("model_path", type=click.Path(exists=True, dir_okay=False, path_type=Path))
@click.argument("negatives", nargs=-1, required=True, type=click.Path(exists=True, dir_okay=False, path_type=Path))
@click.option("--register", is_flag=True, help="Search every cyclic shift within the learned tile.")
@click.option("--report-out", type=click.Path(dir_okay=False, path_type=Path), required=True)
def calibrate(model_path: Path, negatives: tuple[Path, ...], register: bool, report_out: Path) -> None:
"""Calibrate a zero-observed-error threshold on NEGATIVES."""
model = load_model(model_path)
threshold = calibrate_threshold(list(negatives), model, register=register)
report_out.parent.mkdir(parents=True, exist_ok=True)
report_out.write_text(
json.dumps(
{
"model": str(model_path),
"model_sha256": artifact_sha256(model_path),
"register": register,
"negative_count": len(negatives),
"threshold": threshold,
},
indent=2,
)
+ "\n",
encoding="utf-8",
)
log.info("Wrote periodic-tile calibration report: %s", report_out)
@main.command()
@click.argument("model_path", type=click.Path(exists=True, dir_okay=False, path_type=Path))
@click.argument("images", nargs=-1, required=True, type=click.Path(exists=True, dir_okay=False, path_type=Path))
@click.option("--register", is_flag=True, help="Search every cyclic shift within the learned tile.")
@click.option("--report-out", type=click.Path(dir_okay=False, path_type=Path), required=True)
def score(model_path: Path, images: tuple[Path, ...], register: bool, report_out: Path) -> None:
"""Score exact-geometry IMAGES with MODEL_PATH."""
model = load_model(model_path)
report_out.parent.mkdir(parents=True, exist_ok=True)
report_out.write_text(
json.dumps(
{
"model": str(model_path),
"model_sha256": artifact_sha256(model_path),
"register": register,
"scores": [asdict(score_image(image, model, register=register)) for image in images],
},
indent=2,
)
+ "\n",
encoding="utf-8",
)
log.info("Wrote periodic-tile score report: %s", report_out)
if __name__ == "__main__":
main()