Files
remove-ai-watermarks/src/remove_ai_watermarks/humanizer.py
T
Victor KuznetsovandClaude Opus 4.8 5d0e6c3a65 fix: harden metadata parsers and engines; sync docs (full-repo review)
Apply fixes from a full-repo review (code, tests, docs).

Security / correctness:
- Clamp attacker-controlled PNG/caBX chunk lengths to the remaining file
  size in metadata.py and noai/c2pa.py (a malformed length no longer drives
  a multi-GB read); skipped chunks seek instead of read.
- noai/isobmff.strip_c2pa_boxes is now fail-safe on a malformed box: return
  the original bytes with a warning instead of silently truncating the tail,
  so metadata --remove can no longer emit a corrupt file.
- doubao_engine._fixed_alpha_map clamps the glyph box to the image (no crash
  on degenerate width-vs-height).
- watermark_remover._run_region_hires gates the phaseCorrelate offset on
  response and magnitude (a spurious shift no longer garbles text) and drops
  the generator after a CPU fallback (no MPS/CPU device mismatch).

Robustness:
- gemini_engine, doubao_engine, region_eraser normalize grayscale and RGBA
  inputs to BGR at the engine entry points.
- image_io.imwrite returns False on an unwritable path (matches cv2).
- invisible_engine guards a None imread result before use.
- trustmark_detector._decoder uses a double-checked threading lock.
- ctrlregen.tiling.tile_positions raises on overlap >= tile.
- humanizer chromatic shift no longer wraps opposite-edge pixels.
- identify OpenAI caveat keyed on the normalized vendor, not a substring.
- Remove the dead "visible --detect-threshold" CLI option.
- publish.yml verifies the release tag matches the package version.

Docs:
- README strength 0.05 to 0.10; .env.example HF_TOKEN marked optional;
  doubao_capture README updated to reverse-alpha-only; CLAUDE.md synced with
  the new behaviors and the batch command.

Tests: new test_security_clamp.py for the read clamp and isobmff fail-safe;
erase CLI coverage; integrity-clash rule 2 end-to-end; multi-tag EXIF
survival and cross-format strip guards; channel/size, tiling, humanizer, and
imwrite regressions. Full suite 493 passed, 2 skipped; ruff and pyright src/
clean.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-05-30 18:00:39 -07:00

59 lines
2.7 KiB
Python

"""Analog Humanizer: film grain and chromatic aberration injection.
Simulates analog film imperfections to defeat digital AI perfection
classifiers. Ported from NeuralBleach.
"""
# cv2/numpy boundary: third-party libs ship no usable element types; relax the
# unknown-type rules for this file only.
# pyright: reportUnknownMemberType=false, reportUnknownArgumentType=false, reportUnknownVariableType=false, reportUnknownParameterType=false, reportMissingTypeArgument=false, reportMissingTypeStubs=false, reportMissingImports=false, reportArgumentType=false, reportAssignmentType=false, reportReturnType=false, reportCallIssue=false, reportIndexIssue=false, reportOperatorIssue=false, reportOptionalMemberAccess=false, reportOptionalCall=false, reportOptionalSubscript=false, reportOptionalOperand=false, reportAttributeAccessIssue=false, reportPrivateImportUsage=false, reportPrivateUsage=false, reportInvalidTypeForm=false, reportConstantRedefinition=false, reportUnnecessaryComparison=false
import cv2
import numpy as np
from numpy.typing import NDArray
def apply_analog_humanizer(image: NDArray, grain_intensity: float = 4.0, chromatic_shift: int = 1) -> NDArray:
"""
Apply Analog Humanizer (film grain and chromatic aberration) to an image.
This simulates analog film imperfections to defeat digital AI perfection classifiers.
Ported from NeuralBleach.
Args:
image: BGR image as numpy array (uint8).
grain_intensity: Standard deviation of the Gaussian noise (film grain).
chromatic_shift: Number of pixels to shift the red/blue color channels.
Returns:
Humanized BGR image.
"""
# Ensure image is BGR
if len(image.shape) != 3 or image.shape[2] != 3:
return image.copy()
# Split channels (OpenCV uses BGR)
# B = 0, G = 1, R = 2
b, g, r = cv2.split(image)
# 1. Chromatic Aberration
# Shift R channel left, B channel right. np.roll is circular, so it wraps
# the opposite edge into a thin colored fringe at the L/R borders; replicate
# the original edge columns there to keep the intended offset interior-only.
if chromatic_shift > 0:
r = np.roll(r, -chromatic_shift, axis=1)
r[:, -chromatic_shift:] = r[:, -chromatic_shift - 1 : -chromatic_shift]
b = np.roll(b, chromatic_shift, axis=1)
b[:, :chromatic_shift] = b[:, chromatic_shift : chromatic_shift + 1]
merged = cv2.merge((b, g, r))
# 2. Film Grain (Gaussian Noise)
if grain_intensity > 0:
img_f = merged.astype(np.float32)
noise = np.random.normal(0, grain_intensity, img_f.shape).astype(np.float32)
humanized = np.clip(img_f + noise, 0, 255).astype(np.uint8)
else:
humanized = merged
return humanized