SDXL img2img regenerates every pixel, so small text and CJK glyphs deform
at the strengths that defeat SynthID (issue #21). With --protect-text a
CJK-native PP-OCRv3 detector (2.4 MB ONNX, cv2.dnn, no torch, cached on
first use) locates text regions and the pass switches to the SDXL
Differential-Diffusion community pipeline: a per-pixel change map keeps
text regions largely intact while the background is regenerated to strip
the watermark. Gated to the SDXL default model; falls back to plain
img2img with a warning when unavailable.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>