blla.segment() is a full-page layout detection model that kills the worker process when called on tiny annotation crops (e.g. 597x89 px). For guided OCR the annotation region IS already the text line, so segmentation is unnecessary. Replace the blla call with a single synthetic BaselineLine that spans the full crop width — rpred then runs recognition on the whole crop. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>