2.6 KiB
Local Installation
Check here for examples: https://github.com/naptha/tesseract.js/blob/master/docs/examples.md
In browser environment, tesseract.js simply provides the API layer. Internally, it opens a WebWorker to handle requests. That worker itself loads code from the Emscripten-built tesseract.js-core which itself is hosted on a CDN. Then it dynamically loads language files hosted on another CDN.
Because of this we recommend loading tesseract.js from a CDN. But if you really need to have all your files local, you can pass extra arguments to TesseractWorker to specify custom paths for workers, languages, and core.
In Node.js environment, the only path you may want to customize is languages/langPath.
Tesseract.recognize(image, langs, {
workerPath: 'https://cdn.jsdelivr.net/npm/tesseract.js@v4.0.3/dist/worker.min.js',
langPath: 'https://tessdata.projectnaptha.com/4.0.0',
corePath: 'https://cdn.jsdelivr.net/npm/tesseract.js-core@v4.0.3',
})
Or
const worker = await createWorker({
workerPath: 'https://cdn.jsdelivr.net/npm/tesseract.js@v4.0.3/dist/worker.min.js',
langPath: 'https://tessdata.projectnaptha.com/4.0.0',
corePath: 'https://cdn.jsdelivr.net/npm/tesseract.js-core@v4.0.3',
});
workerPath
A string specifying the location of the worker.js file.
langPath
A string specifying the location of the tesseract language files, with default value 'https://tessdata.projectnaptha.com/4.0.0'. Language file URLs are calculated according to the formula langPath + langCode + '.traineddata.gz'.
corePath
A string specifying the location of the tesseract.js-core files, with default value 'https://cdn.jsdelivr.net/npm/tesseract.js-core@v4.0.3'.
corePath should be set to a directory containing both tesseract-core-simd.wasm.js and tesseract-core.wasm.js. Tesseract.js will load either tesseract-core-simd.wasm.js or tesseract-core.wasm.js from the directory depending on whether the users' device supports SIMD (see https://webassembly.org/roadmap/).
To avoid breaking old code, when corePath is set to a specific .js file (e.g. https://cdn.jsdelivr.net/npm/tesseract.js-core@v4.0.3/tesseract-core.wasm.js), it will load that file regardless of whether the users' device supports SIMD or not. This behavior only exists to preserve backwards compatibility—setting corePath to a specific .js file is strongly discouraged. Doing so will either result in much slower performance (if tesseract-core.wasm.js is specified) or failure to run on certain devices (if tesseract-core-simd.wasm.js is specified).