From 7bc49c32e9cdd3363215e24b47d7721ac17bafc8 Mon Sep 17 00:00:00 2001
From: icarus <eurfelux@gmail.com>
Date: Sun, 24 Aug 2025 20:46:12 +0800
Subject: [PATCH] =?UTF-8?q?refactor(ocr):=20=E7=A7=BB=E9=99=A4=E7=8B=AC?=
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将灰度处理功能直接集成到OCR预处理中，不再需要单独的image模块
添加normalise和threshold处理以提升OCR识别效果
---
 src/main/utils/image.ts | 11 -----------
 src/main/utils/ocr.ts   |  8 +++++---
 2 files changed, 5 insertions(+), 14 deletions(-)
 delete mode 100644 src/main/utils/image.ts

diff --git a/src/main/utils/image.ts b/src/main/utils/image.ts
deleted file mode 100644
index ad78a44d3d..0000000000
--- a/src/main/utils/image.ts
+++ /dev/null
@@ -1,11 +0,0 @@
-import sharp from 'sharp'
-
-/**
- * 将图片转换为灰度图
- * @param image 输入的图片 Buffer
- * @returns Promise<Buffer> 处理后的灰度图片 Buffer
- * @throws {Error} 当图片处理失败时抛出错误
- */
-export const greyScale = (image: Buffer): Promise<Buffer> => {
-  return sharp(image).greyscale().toBuffer()
-}
diff --git a/src/main/utils/ocr.ts b/src/main/utils/ocr.ts
index 911dae09dc..105d6bc858 100644
--- a/src/main/utils/ocr.ts
+++ b/src/main/utils/ocr.ts
@@ -1,16 +1,18 @@
 import { ImageFileMetadata } from '@types'
 import { readFile } from 'fs/promises'
-
-import { greyScale } from './image'
+import sharp from 'sharp'
 
 const preprocessImage = (buffer: Buffer) => {
-  return greyScale(buffer)
+  // threshold 70 is hard-encoded
+  const result = sharp(buffer).greyscale().normalise().threshold(70).toBuffer()
+  return result
 }
 
 /**
  * 加载并预处理OCR图像
  * @param file - 图像文件元数据
  * @returns 预处理后的图像Buffer
+ * @throws {Error} 当文件不存在或无法读取时抛出错误；当图像预处理失败时抛出错误
  *
  * 预处理步骤:
  * 1. 读取图像文件