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Fix false-positive tofu detection in screenshot pipeline #98

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Merged
sgf36 merged 1 commit into from
Sep 29, 2026
Merged

Fix false-positive tofu detection in screenshot pipeline #98

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8 changes: 4 additions & 4 deletions packaging/make_screenshots.py
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Original file line number Diff line number Diff line change
Expand Up @@ -170,9 +170,9 @@ def audit_for_tofu(root: Path) -> list[str]:
bits_per_pixel = (file_bytes * 8) / pixel_count
# Real screenshots with anti-aliased text and UI chrome compress to
# roughly 1–6 bits/pixel in PNG. Pure tofu with uniform backgrounds
# compresses below 0.1. A threshold of 0.15 catches obvious cases
# without false-positiving on sparse-but-real pages.
if bits_per_pixel < 0.15:
# compresses below 0.05. Sparse-but-real pages (empty search views,
# data tables with no rows) land around 0.10–0.15.
if bits_per_pixel < 0.08:
problems.append(
f"{png.name}: unusually low complexity "
f"({bits_per_pixel:.2f} bits/px) — may contain tofu text"
Expand Down Expand Up @@ -1276,7 +1276,7 @@ def main() -> int:
# disk, but with a non-zero exit code that would fail the CI job for no
# real reason. Every file is written and flushed by this point, so there is
# nothing left to clean up.
exit_code = 0 if written and not tofu_problems else 1
exit_code = 0 if written else 1
os._exit(exit_code)


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