指定字体文件的位置，方便离线部署

Author: self4m

docs/version3.x/pipeline_usage/OCR.en.md

@@ -1845,3 +1845,38 @@ from paddleocr import PaddleOCR
 
 pipeline = PaddleOCR(paddlex_config="PaddleOCR.yaml")  
 ```
+
+#### 4.2.3 Specifying the Local Font File Path via Environment Variables
+Before initializing the production line object, you can set an environment variable to specify the local font file path. This enables the production line to use the specified font when saving the annotated result image via the `save_to_img` method.  
+This approach is convenient for offline deployment as it eliminates the need to download font files over the network and simplifies file management. **It is essential to ensure that the specified font file exists!** **
+
+Suppose the font file `simfang.ttf` is stored in the `fonts` folder in the current directory. 
+
+Python script: 
+
+```python
+import os
+
+# Specify the location of the font file before initializing the production line.
+os.environ["PADDLE_PDX_LOCAL_FONT_FILE_PATH"] = "./fonts/simfang.ttf"
+
+from paddleocr import PaddleOCR
+
+ocr = PaddleOCR(
+    use_doc_orientation_classify=False, 
+    use_doc_unwarping=False, 
+    use_textline_orientation=False) # text detection + text recognition
+# ocr = PaddleOCR(use_doc_orientation_classify=True, use_doc_unwarping=True) # text image preprocessing + text detection + textline orientation classification + text recognition
+# ocr = PaddleOCR(use_doc_orientation_classify=False, use_doc_unwarping=False) # text detection + textline orientation classification + text recognition
+# ocr = PaddleOCR(
+#     text_detection_model_name="PP-OCRv5_server_det",
+#     text_recognition_model_name="PP-OCRv5_server_rec",
+#     use_doc_orientation_classify=False,
+#     use_doc_unwarping=False,
+#     use_textline_orientation=False) # Switch to PP-OCRv5_server models
+result = ocr.predict("./general_ocr_002.png")
+for res in result:
+    res.print()
+    res.save_to_img("output")
+    res.save_to_json("output")
+```

docs/version3.x/pipeline_usage/OCR.md

@@ -1847,3 +1847,39 @@ from paddleocr import PaddleOCR
 
 pipeline = PaddleOCR(paddlex_config="PaddleOCR.yaml")
 ```
+
+#### 4.2.3 通过环境变量指定使用本地字体文件路径
+在初始化产线对象前，可通过设置环境变量，指定本地字体文件路径，使产线在执行 save_to_img 方法保存标注结果图像时使用该字体。  
+方便离线部署时无需网络下载字体文件，便于文件的管理，**通过该方法需要确保指定的字体文件存在！**  
+
+示例如下：  
+假设字体文件 `simfang.ttf` 存放于当前目录下的 `fonts` 文件夹内
+
+Python 脚本：
+
+```python
+import os
+
+# 在初始化产线前指定字体文件的位置
+os.environ["PADDLE_PDX_LOCAL_FONT_FILE_PATH"] = "./fonts/simfang.ttf"
+
+from paddleocr import PaddleOCR
+
+ocr = PaddleOCR(
+    use_doc_orientation_classify=False, 
+    use_doc_unwarping=False, 
+    use_textline_orientation=False) # 文本检测+文本识别
+# ocr = PaddleOCR(use_doc_orientation_classify=True, use_doc_unwarping=True) # 文本图像预处理+文本检测+方向分类+文本识别
+# ocr = PaddleOCR(use_doc_orientation_classify=False, use_doc_unwarping=False) # 文本检测+文本行方向分类+文本识别
+# ocr = PaddleOCR(
+#     text_detection_model_name="PP-OCRv5_server_det",
+#     text_recognition_model_name="PP-OCRv5_server_rec",
+#     use_doc_orientation_classify=False,
+#     use_doc_unwarping=False,
+#     use_textline_orientation=False) # 更换 PP-OCRv5_server 模型
+result = ocr.predict("./general_ocr_002.png")
+for res in result:
+    res.print()
+    res.save_to_img("output")
+    res.save_to_json("output")
+```