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Diffstat (limited to 'src/offscreen/ocr/index.js')
| -rw-r--r-- | src/offscreen/ocr/index.js | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/src/offscreen/ocr/index.js b/src/offscreen/ocr/index.js index 432811e..aab9da8 100644 --- a/src/offscreen/ocr/index.js +++ b/src/offscreen/ocr/index.js @@ -4,6 +4,15 @@ let ocrWorker = null; const WORKER_PATH = chrome.runtime.getURL("offscreen/ocr/static/worker.min.js"); const CORE_PATH = chrome.runtime.getURL("offscreen/ocr/static"); +/** + * Creates (or reuses) a Tesseract.js worker and recognises text from + * the given image data URL. The worker is configured to only recognise + * uppercase alphanumerics (excluding `0`, `O`, `1`, `I`) suitable for + * CAPTCHA text. + * + * @param {string} dataURL - A `data:image/png;base64,…` string. + * @returns {{ text: string, confidence: number }} + */ async function performOcrInOffscreen(dataURL) { if (!ocrWorker) { ocrWorker = await Tesseract.createWorker("eng", 1, { @@ -23,6 +32,11 @@ async function performOcrInOffscreen(dataURL) { } // Listen for messages from the Service Worker +/** + * Handles two message types from the background service worker: + * - `"OFFSCREEN_OCR_REQUEST"`: runs OCR on the supplied data URL. + * - `"OFFSCREEN_TERMINATE_OCR_WORKER"`: terminates the worker to free memory. + */ chrome.runtime.onMessage.addListener((message, sender, sendResponse) => { if (message.type === "OFFSCREEN_OCR_REQUEST" && message.dataURL) { performOcrInOffscreen(message.dataURL) |