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https://github.com/MBombeck/HealthLog.git
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Marc-André Bombeck
028b0d8685
Replace the separate, capability-gated scan button with a single Add menu: "Scan a document" (OCR) or "Add a value manually". The scan entry appears only when the capability probe reports a usable mode, and routes to native vision or local in-browser OCR (tesseract.js, lazy-loaded, deu+eng, images only) per the resolved mode. Add the local-OCR opt-in toggle to the Labs settings page with honest "less accurate — review every value" copy. Surface range confidence prominently on the OCR review screen for new numeric biomarkers, where the extracted range becomes the catalog range: flag low range-confidence or a missing range so the user verifies it.
63 lines
2.3 KiB
TypeScript
63 lines
2.3 KiB
TypeScript
/**
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* v1.18.10 — in-browser (local) OCR for lab-report scans.
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*
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* Used by the TEXT-mode Lab-OCR path: a user whose AI provider cannot read
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* images (ChatGPT-OAuth/Codex, a text-only model) OCR's the photo HERE, in the
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* browser, and only the extracted TEXT is POSTed to `/api/labs/ocr/extract`.
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* The raw image never leaves the device.
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*
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* tesseract.js (WASM) is LAZY-loaded via `await import(...)` so the multi-MB
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* worker + WASM core + `deu+eng` traineddata land in the browser only when the
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* user actually scans in text mode — never at app boot, and never for the
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* higher-accuracy vision path. This mirrors the chart-defer discipline.
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*
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* Images only — tesseract.js cannot read PDFs, matching the vision path's
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* image-only constraint for non-Anthropic providers.
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*/
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/** German + English: a German lab sheet needs `deu` for ä/ö/ü/ß; `eng` covers
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* the many English analyte names and units that appear on the same sheet. */
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const OCR_LANGS = "deu+eng";
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export class LocalOcrError extends Error {
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constructor(message: string) {
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super(message);
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this.name = "LocalOcrError";
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}
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}
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/**
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* OCR an image file entirely in the browser and return the extracted plain
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* text. Throws `LocalOcrError` when the engine fails to load or recognise.
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*
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* A fresh worker is created and terminated per call. The traineddata is
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* browser-cached after the first run, so the cost is paid once.
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*/
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export async function ocrImageToText(file: File): Promise<string> {
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// Lazy import — keeps tesseract.js out of the main bundle.
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let createWorker: typeof import("tesseract.js").createWorker;
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try {
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({ createWorker } = await import("tesseract.js"));
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} catch {
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throw new LocalOcrError("Failed to load the local OCR engine");
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}
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const worker = await createWorker(OCR_LANGS);
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try {
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const {
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data: { text },
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} = await worker.recognize(file);
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const trimmed = text.trim();
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if (!trimmed) {
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throw new LocalOcrError("No text could be read from the image");
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}
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return trimmed;
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} catch (err) {
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if (err instanceof LocalOcrError) throw err;
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throw new LocalOcrError("Local OCR failed to read the image");
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} finally {
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// Free the WASM worker; the traineddata stays browser-cached.
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await worker.terminate().catch(() => {});
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}
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}
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