update README

README.md

 # PaddleOCR
 ## 论文
-det、rec、cls三个模型的backbone基于mobilenetv3，可参考mobilenetv3的相关论文
+PaddleOCR通过det、rec、cls三个模型分别实现字符检测、字符识别和字符方向分类的应用
+det模型主要用DB算法，参考论文如下：
+
+https://arxiv.org/pdf/1911.08947.pdf
+
+rec模型主要用SVTR算法，参考论文如下：
+
+https://arxiv.org/pdf/2205.00159.pdf
+
+cls模型用mobilenetv3实现通用分类，参考论文如下：
 
 https://arxiv.org/pdf/1905.02244.pdf
 ## 模型结构
-```
 det:
-  └─ Backbone:
-      └─ name: MobileNetV3
-      └─ scale: 0.5
-      └─ model_name: large
-  └─ Neck:
-      └─ name: DBFPN
-      └─ out_channels: 256
-  └─ Head:
-      └─ name: DBHead
-
+![image](https://developer.hpccube.com/codes/modelzoo/paddleocr/-/raw/main/configs/det/dbnet-arc.png)
 rec:
-  └─ Backbone:
-      └─ name: MobileNetV1Enhance
-      └─ scale: 0.5
-      └─ last_conv_stride: [1, 2]
-      └─ last_pool_type: avg
-  └─ Head:
-      └─ name: MultiHead
-      └─ head_list:
-        └─ CTCHead:
-            └─ Neck:
-              └─ name: svtr
-              └─ dims: 64
-              └─ depth: 2
-              └─ hidden_dims: 120
-              └─ use_guide: True
-            └─ Head:
-              └─ fc_decay: 0.00001
-        └─ SARHead:
-            └─ enc_dim: 512
-            └─ max_text_length: *max_text_length
-
+![image](https://developer.hpccube.com/codes/modelzoo/paddleocr/-/raw/main/configs/rec/SVTR-arc.png)
 cls:
-  └─ Backbone:
-      └─ name: MobileNetV3
-      └─ scale: 0.35
-      └─ model_name: small
-  └─ Head:
-      └─ name: ClsHead
-      └─ class_dim: 2
-```
+![image](https://developer.hpccube.com/codes/modelzoo/paddleocr/-/raw/main/configs/cls/mobilenetv3-arc.png)
 ## 算法原理
 det->cls->rec->text
 ## 数据集