feat(ocr): 添加OCR功能支持

实现基于Tesseract的OCR功能，包括文件类型检查、服务接口和IPC通信
新增OCR相关类型定义和服务实现

packages/shared/IpcChannel.ts

@@ -281,5 +281,8 @@ export enum IpcChannel {
   TRACE_ADD_STREAM_MESSAGE = 'trace:addStreamMessage',
 
   // CodeTools
-  CodeTools_Run = 'code-tools:run'
+  CodeTools_Run = 'code-tools:run',
+
+  // OCR
+  OCR_ocr = 'ocr:ocr'
 }

src/main/ipc.ts

@@ -30,6 +30,7 @@ import { openTraceWindow, setTraceWindowTitle } from './services/NodeTraceServic
 import NotificationService from './services/NotificationService'
 import * as NutstoreService from './services/NutstoreService'
 import ObsidianVaultService from './services/ObsidianVaultService'
+import { ipcOcr } from './services/ocr/OcrService'
 import { proxyManager } from './services/ProxyManager'
 import { pythonService } from './services/PythonService'
 import { FileServiceManager } from './services/remotefile/FileServiceManager'
@@ -709,4 +710,7 @@ export function registerIpc(mainWindow: BrowserWindow, app: Electron.App) {
 
   // CodeTools
   ipcMain.handle(IpcChannel.CodeTools_Run, codeToolsService.run)
+
+  // OCR
+  ipcMain.handle(IpcChannel.OCR_ocr, ipcOcr)
 }

src/main/services/ocr/OcrService.ts

@@ -0,0 +1,79 @@
+import { loggerService } from '@logger'
+import { ImageFileMetadata, isImageFile } from '@types'
+import {
+  ImageOcrProvider,
+  isBuiltinOcrProvider,
+  isImageOcrProvider,
+  OcrProvider,
+  OcrResult,
+  SupportedOcrFile
+} from 'src/renderer/src/types/ocr'
+
+import { getTesseractWorker } from './TesseractService'
+
+const logger = loggerService.withContext('OcrService')
+
+/**
+ * ocr by tesseract
+ * @param file image file
+ * @returns ocr result
+ * @throws {Error}
+ */
+const tesseractOcr = async (file: ImageFileMetadata): Promise<string> => {
+  try {
+    const worker = await getTesseractWorker()
+    const ret = await worker.recognize(file.path)
+    return ret.data.text
+  } catch (e) {
+    const message = 'Failed to ocr with tesseract.'
+    logger.error(message, e as Error)
+    throw new Error(message)
+  }
+}
+
+/**
+ * ocr image file
+ * @param file image file
+ * @param provider ocr provider that supports image ocr
+ * @returns ocr result
+ * @throws {Error}
+ */
+const imageOcr = async (file: ImageFileMetadata, provider: ImageOcrProvider): Promise<OcrResult> => {
+  if (isBuiltinOcrProvider(provider)) {
+    let text: string
+    switch (provider.id) {
+      case 'tesseract':
+        text = await tesseractOcr(file)
+        return { text }
+      default:
+        throw new Error(`Unsupported built-in ocr provider: ${provider.id}`)
+    }
+  }
+  throw new Error(`Provider ${provider.id} is not supported.`)
+}
+
+/**
+ * ocr a file
+ * @param file any supported file
+ * @param provider ocr provider
+ * @returns ocr result
+ * @throws {Error}
+ */
+export const ocr = async (file: SupportedOcrFile, provider: OcrProvider): Promise<OcrResult> => {
+  if (isImageFile(file) && isImageOcrProvider(provider)) {
+    return imageOcr(file, provider)
+  }
+  throw new Error(`File type and provider capability is not matched, otherwise one of them is not supported.`)
+}
+
+/**
+ * ocr a file
+ * @param _ ipc event
+ * @param file any supported file
+ * @param provider ocr provider
+ * @returns ocr result
+ * @throws {Error}
+ */
+export const ipcOcr = async (_: Electron.IpcMainInvokeEvent, ...args: Parameters<typeof ocr>) => {
+  return ocr(...args)
+}

src/main/services/ocr/TesseractService.ts

@@ -0,0 +1,123 @@
+import Tesseract, { createWorker } from 'tesseract.js'
+
+let worker: Tesseract.Worker | null = null
+
+// const languageCodeMap: Record<string, string> = {
+//   'af-za': 'afr',
+//   'am-et': 'amh',
+//   'ar-sa': 'ara',
+//   'as-in': 'asm',
+//   'az-az': 'aze',
+//   'az-cyrl-az': 'aze_cyrl',
+//   'be-by': 'bel',
+//   'bn-bd': 'ben',
+//   'bo-cn': 'bod',
+//   'bs-ba': 'bos',
+//   'bg-bg': 'bul',
+//   'ca-es': 'cat',
+//   'ceb-ph': 'ceb',
+//   'cs-cz': 'ces',
+//   'zh-cn': 'chi_sim',
+//   'zh-tw': 'chi_tra',
+//   'chr-us': 'chr',
+//   'cy-gb': 'cym',
+//   'da-dk': 'dan',
+//   'de-de': 'deu',
+//   'dz-bt': 'dzo',
+//   'el-gr': 'ell',
+//   'en-us': 'eng',
+//   'enm-gb': 'enm',
+//   'eo-world': 'epo',
+//   'et-ee': 'est',
+//   'eu-es': 'eus',
+//   'fa-ir': 'fas',
+//   'fi-fi': 'fin',
+//   'fr-fr': 'fra',
+//   'frk-de': 'frk',
+//   'frm-fr': 'frm',
+//   'ga-ie': 'gle',
+//   'gl-es': 'glg',
+//   'grc-gr': 'grc',
+//   'gu-in': 'guj',
+//   'ht-ht': 'hat',
+//   'he-il': 'heb',
+//   'hi-in': 'hin',
+//   'hr-hr': 'hrv',
+//   'hu-hu': 'hun',
+//   'iu-ca': 'iku',
+//   'id-id': 'ind',
+//   'is-is': 'isl',
+//   'it-it': 'ita',
+//   'ita-it': 'ita_old',
+//   'jv-id': 'jav',
+//   'ja-jp': 'jpn',
+//   'kn-in': 'kan',
+//   'ka-ge': 'kat',
+//   'kat-ge': 'kat_old',
+//   'kk-kz': 'kaz',
+//   'km-kh': 'khm',
+//   'ky-kg': 'kir',
+//   'ko-kr': 'kor',
+//   'ku-tr': 'kur',
+//   'la-la': 'lao',
+//   'la-va': 'lat',
+//   'lv-lv': 'lav',
+//   'lt-lt': 'lit',
+//   'ml-in': 'mal',
+//   'mr-in': 'mar',
+//   'mk-mk': 'mkd',
+//   'mt-mt': 'mlt',
+//   'ms-my': 'msa',
+//   'my-mm': 'mya',
+//   'ne-np': 'nep',
+//   'nl-nl': 'nld',
+//   'no-no': 'nor',
+//   'or-in': 'ori',
+//   'pa-in': 'pan',
+//   'pl-pl': 'pol',
+//   'pt-pt': 'por',
+//   'ps-af': 'pus',
+//   'ro-ro': 'ron',
+//   'ru-ru': 'rus',
+//   'sa-in': 'san',
+//   'si-lk': 'sin',
+//   'sk-sk': 'slk',
+//   'sl-si': 'slv',
+//   'es-es': 'spa',
+//   'spa-es': 'spa_old',
+//   'sq-al': 'sqi',
+//   'sr-rs': 'srp',
+//   'sr-latn-rs': 'srp_latn',
+//   'sw-tz': 'swa',
+//   'sv-se': 'swe',
+//   'syr-sy': 'syr',
+//   'ta-in': 'tam',
+//   'te-in': 'tel',
+//   'tg-tj': 'tgk',
+//   'tl-ph': 'tgl',
+//   'th-th': 'tha',
+//   'ti-er': 'tir',
+//   'tr-tr': 'tur',
+//   'ug-cn': 'uig',
+//   'uk-ua': 'ukr',
+//   'ur-pk': 'urd',
+//   'uz-uz': 'uzb',
+//   'uz-cyrl-uz': 'uzb_cyrl',
+//   'vi-vn': 'vie',
+//   'yi-us': 'yid'
+// }
+
+export const getTesseractWorker = async (): Promise<Tesseract.Worker> => {
+  if (!worker) {
+    // for now, only support limited languages
+    worker = await createWorker(['chi_sim', 'chi_tra', 'eng'])
+  }
+  return worker
+}
+
+export const disposeTesseractWorker = async () => {
+  if (worker) {
+    await worker.terminate()
+    worker = null
+  }
+}

src/preload/index.ts

@@ -25,6 +25,7 @@ import {
 } from '@types'
 import { contextBridge, ipcRenderer, OpenDialogOptions, shell, webUtils } from 'electron'
 import { Notification } from 'src/renderer/src/types/notification'
+import { OcrProvider, OcrResult, SupportedOcrFile } from 'src/renderer/src/types/ocr'
 import { CreateDirectoryOptions } from 'webdav'
 
 import type { ActionItem } from '../renderer/src/types/selectionTypes'
@@ -406,6 +407,10 @@ const api = {
       env: Record<string, string>,
       options?: { autoUpdateToLatest?: boolean }
     ) => ipcRenderer.invoke(IpcChannel.CodeTools_Run, cliTool, model, directory, env, options)
+  },
+  ocr: {
+    ocr: (file: SupportedOcrFile, provider: OcrProvider): Promise<OcrResult> =>
+      ipcRenderer.invoke(IpcChannel.OCR_ocr, file, provider)
   }
 }
 

src/renderer/src/types/ocr.ts

@@ -75,3 +75,7 @@ export type SupportedOcrFile = FileMetadata & {
 export const isSupportedOcrFile = (file: FileMetadata): file is SupportedOcrFile => {
   return isSupportedOcrFileType(file.type)
 }
+
+export type OcrResult = {
+  text: string
+}