refine doc and demo code

README.md

@@ -262,8 +262,8 @@ curl -H "Content-Type:application/json" -X POST -d '{"feed":[{"url": "https://pa
 
 ### About Efficiency
 - [How to profile Paddle Serving latency?](python/examples/util)
-- [How to optimize performance?(Chinese)](doc/MULTI_SERVICE_ON_ONE_GPU_CN.md)
-- [Deploy multi-services on one GPU(Chinese)](doc/PERFORMANCE_OPTIM_CN.md)
+- [How to optimize performance?(Chinese)](doc/PERFORMANCE_OPTIM_CN.md)
+- [Deploy multi-services on one GPU(Chinese)](doc/MULTI_SERVICE_ON_ONE_GPU_CN.md)
 - [CPU Benchmarks(Chinese)](doc/BENCHMARKING.md)
 - [GPU Benchmarks(Chinese)](doc/GPU_BENCHMARKING.md)
 

README_CN.md

@@ -268,8 +268,8 @@ curl -H "Content-Type:application/json" -X POST -d '{"feed":[{"url": "https://pa
 
 ### 关于Paddle Serving性能
 - [如何测试Paddle Serving性能？](python/examples/util/)
-- [如何优化性能?](doc/MULTI_SERVICE_ON_ONE_GPU_CN.md)
-- [在一张GPU上启动多个预测服务](doc/PERFORMANCE_OPTIM_CN.md)
+- [如何优化性能?](doc/PERFORMANCE_OPTIM_CN.md)
+- [在一张GPU上启动多个预测服务](doc/MULTI_SERVICE_ON_ONE_GPU_CN.md)
 - [CPU版Benchmarks](doc/BENCHMARKING.md)
 - [GPU版Benchmarks](doc/GPU_BENCHMARKING.md)
 

python/examples/imagenet/image_classification_service.py

@@ -13,11 +13,9 @@
 # limitations under the License.
 
 from paddle_serving_server.web_service import WebService
+from paddle_serving_app import ImageReader
 import sys
-import cv2
 import base64
-import numpy as np
-from paddle_serving_app import ImageReader
 
 
 class ImageService(WebService):