Update visualization.md

doc/doc_ch/visualization.md

@@ -40,15 +40,28 @@
 
 <a name="通用中文OCR"></a>
 ## 通用中文OCR效果展示
-![](../imgs_results/chinese_db_crnn_server/11.jpg)
-![](../imgs_results/chinese_db_crnn_server/2.jpg)
-![](../imgs_results/chinese_db_crnn_server/8.jpg)
+
+<div align="center">
+    <img src="../imgs_results/chinese_db_crnn_server/11.jpg" width="800">
+</div>
+
+<div align="center">
+    <img src="../imgs_results/chinese_db_crnn_server/2.jpg" width="800">
+</div>
+
+<div align="center">
+    <img src="../imgs_results/chinese_db_crnn_server/8.jpg" width="800">
+</div>
 
 <a name="支持空格的中文OCR"></a>
 ## 支持空格的中文OCR效果展示
 
 ### 轻量级模型
-![](../imgs_results/img_11.jpg)
+<div align="center">
+    <img src="../imgs_results/img_11.jpg" width="800">
+</div>
 
 ### 通用模型
-![](../imgs_results/chinese_db_crnn_server/en_paper.jpg)
+<div align="center">
+    <img src="../imgs_results/chinese_db_crnn_server/en_paper.jpg" width="800">
+</div>