Several ePOE tools read a small, fixed patch of the screen rather than the clipboard: the Well of Souls revealed-tier read, the Rune Scout, the Ritual Loot scanner, and the stash-open / slot-hover helpers. That reading is done with OCR — optical character recognition — and it now works on Linux as well as Windows.
Two engines, chosen for you
ePOE carries two OCR backends behind one service and picks between them automatically. There is nothing to set up.
- Windows OCR — the recognition built into Windows (
Windows.Media.Ocr). It is fast, needs no download, and is the default on Windows. - A bundled cross-platform engine — Tesseract with OpenCV, running as WebAssembly inside the app. It is the only engine on Linux (Windows OCR does not exist there) and a fallback on Windows if the built-in one ever can't start.
On Windows you get the built-in engine; everywhere else, and on a Windows box where the built-in one fails to start, the bundled engine carries the load. Either way the tools — and their hotkeys and pages — behave exactly the same.
The bundled assets (~6 MB)
The cross-platform engine needs about 6 MB of model and library files. In a normal installed build these ship with the app, so it just works. They are only ever absent in a bare development checkout that hasn't fetched them; when that happens the bundled engine reports itself unavailable and Windows quietly uses its built-in OCR instead. On Linux without the assets there is no OCR to fall back to, so the scanners will say they couldn't read the screen.
The Linux word-box caveat
The built-in Windows engine returns each recognised word with its own position on screen. The bundled engine returns the text of each line but not per-word positions. For reading a reward board or an item name — where ePOE wants the words, not their pixels — this makes no difference. The one place it matters is a feature that paints something onto an exact word, such as a stash price badge lining up with a specific cell: on Linux that positioning is coarser because it only has the line to work with. The text is still read correctly; only the pixel-perfect placement is affected.
It never reads game memory
Whichever engine runs, OCR only ever looks at a bounded region of the screen that ePOE captures locally and reads on your own machine. It does not touch Path of Exile's memory, and the captured pixels never leave the PC. Which engine is in use is a per-machine fact, so it is one of the settings that is never carried to your other machines by Cloud Sync.
Related
- Well of Souls, Rune Scout and Ritual Loot scanner — the scanners this powers.