feat(ocr): warn about OCR confidence too low

apps/client/src/translations/en/translation.json

@@ -2093,7 +2093,9 @@
     "process_now": "Process OCR",
     "processing": "Processing...",
     "processing_started": "OCR processing has been started. Please wait a moment and refresh.",
+    "processing_complete": "OCR processing complete.",
     "processing_failed": "Failed to start OCR processing",
+    "text_filtered_low_confidence": "OCR detected text with {{confidence}}% confidence, but it was discarded because your minimum threshold is {{threshold}}%.\n\nYou can adjust the threshold in Options → Media.",
     "view_extracted_text": "View extracted text (OCR)"
   },
   "command_palette": {

apps/client/src/widgets/type_widgets/ReadOnlyTextRepresentation.tsx

@@ -1,6 +1,6 @@
 import "./ReadOnlyTextRepresentation.css";
 
-import type { TextRepresentationResponse } from "@triliumnext/commons";
+import type { OCRProcessResponse, TextRepresentationResponse } from "@triliumnext/commons";
 import { useEffect, useState } from "preact/hooks";
 
 import { t } from "../../services/i18n";
@@ -62,10 +62,27 @@ export function TextRepresentation({ textUrl, processUrl }: TextRepresentationPr
     async function processOCR() {
         setProcessing(true);
         try {
-            const response = await server.post<{ success: boolean; message?: string }>(processUrl, { forceReprocess: true });
+            const response = await server.post<OCRProcessResponse>(processUrl, { forceReprocess: true });
             if (response.success) {
-                toast.showMessage(t("ocr.processing_started"));
-                setTimeout(fetchText, 2000);
+                const result = response.result;
+                const minConfidence = response.minConfidence ?? 0;
+
+                // Check if text was filtered due to low confidence
+                if (result && !result.text && result.confidence > 0 && minConfidence > 0) {
+                    const confidencePercent = Math.round(result.confidence * 100);
+                    const thresholdPercent = Math.round(minConfidence * 100);
+                    toast.showMessage(
+                        t("ocr.text_filtered_low_confidence", {
+                            confidence: confidencePercent,
+                            threshold: thresholdPercent
+                        }),
+                        10000, // Show for 10 seconds since this is important info
+                        "bx bx-info-circle"
+                    );
+                } else {
+                    toast.showMessage(t("ocr.processing_complete"));
+                }
+                setTimeout(fetchText, 500);
             } else {
                 toast.showError(response.message || t("ocr.processing_failed"));
             }

apps/server/src/routes/api/ocr.ts

@@ -1,10 +1,16 @@
-import { TextRepresentationResponse } from "@triliumnext/commons";
+import type { OCRProcessResponse, TextRepresentationResponse } from "@triliumnext/commons";
 import type { Request } from "express";
 
 import becca from "../../becca/becca.js";
 import ocrService from "../../services/ocr/ocr_service.js";
+import options from "../../services/options.js";
 import sql from "../../services/sql.js";
 
+function getMinConfidenceThreshold(): number {
+    const minConfidence = options.getOption('ocrMinConfidence') ?? 0;
+    return parseFloat(minConfidence);
+}
+
 /**
  * @swagger
  * /api/ocr/process-note/{noteId}:
@@ -48,7 +54,7 @@ import sql from "../../services/sql.js";
  *       - session: []
  *     tags: ["ocr"]
  */
-async function processNoteOCR(req: Request<{ noteId: string }>) {
+async function processNoteOCR(req: Request<{ noteId: string }>): Promise<OCRProcessResponse | [number, OCRProcessResponse]> {
     const { noteId } = req.params;
     const { language, forceReprocess = false } = req.body || {};
 
@@ -62,7 +68,11 @@ async function processNoteOCR(req: Request<{ noteId: string }>) {
         return [400, { success: false, message: 'Note is not an image or has unsupported format' }];
     }
 
-    return { success: true, result };
+    return {
+        success: true,
+        result,
+        minConfidence: getMinConfidenceThreshold()
+    };
 }
 
 /**
@@ -108,7 +118,7 @@ async function processNoteOCR(req: Request<{ noteId: string }>) {
  *       - session: []
  *     tags: ["ocr"]
  */
-async function processAttachmentOCR(req: Request<{ attachmentId: string }>) {
+async function processAttachmentOCR(req: Request<{ attachmentId: string }>): Promise<OCRProcessResponse | [number, OCRProcessResponse]> {
     const { attachmentId } = req.params;
     const { language, forceReprocess = false } = req.body || {};
 
@@ -122,7 +132,11 @@ async function processAttachmentOCR(req: Request<{ attachmentId: string }>) {
         return [400, { success: false, message: 'Attachment is not an image or has unsupported format' }];
     }
 
-    return { success: true, result };
+    return {
+        success: true,
+        result,
+        minConfidence: getMinConfidenceThreshold()
+    };
 }
 
 /**

packages/commons/src/lib/server_api.ts

@@ -295,6 +295,20 @@ export interface TextRepresentationResponse {
     message?: string;
 }
 
+export interface OCRProcessResponse {
+    success: boolean;
+    message?: string;
+    result?: {
+        text: string;
+        confidence: number;
+        extractedAt: string;
+        language?: string;
+        pageCount?: number;
+    };
+    /** The minimum confidence threshold that was applied (0-1 scale). */
+    minConfidence?: number;
+}
+
 export interface IconRegistry {
     sources: {
         prefix: string;