getDetectLanguageOncePerDocument

Indicates whether automatic language detection (the "auto" OCR language) runs once for the whole document instead of once per page. When enabled, the first page that needs a language runs the detection and every other page of the same document reuses that result, so a document pays the detection cost once rather than once per page. Disable it to detect every page independently — what a document whose pages are in different languages needs — at the cost of a full page recognition pass per page.