diff --git a/python/examples/imagenet/benchmark_batch.py.lprof b/python/examples/imagenet/benchmark_batch.py.lprof
deleted file mode 100644
index 7ff4f1411ded79aba3390e606193ec4fedacf06f..0000000000000000000000000000000000000000
Binary files a/python/examples/imagenet/benchmark_batch.py.lprof and /dev/null differ
diff --git a/python/examples/imagenet/test_image_reader.py b/python/examples/imagenet/test_image_reader.py
new file mode 100644
index 0000000000000000000000000000000000000000..b3e1aac786360838304e03ec284076ea834ae888
--- /dev/null
+++ b/python/examples/imagenet/test_image_reader.py
@@ -0,0 +1,37 @@
+# Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from paddle_serving_app.reader.image_reader import String2Image, Base64ToImage, Sequential
+import base64
+
+
+def test_String2Image():
+    with open("./daisy.jpg") as f:
+        img_str = f.read()
+    seq = Sequential([String2Image()])
+    img = seq(img_str)
+    assert (img.shape == (563, 500, 3))
+
+
+def test_Base64ToImage():
+    with open("./daisy.jpg") as f:
+        img_str = f.read()
+    seq = Sequential([Base64ToImage()])
+    img = seq(base64.b64encode(img_str))
+    assert (img.shape == (563, 500, 3))
+
+
+if __name__ == "__main__":
+    test_String2Image()
+    test_Base64ToImage()
diff --git a/python/paddle_serving_app/reader/image_reader.py b/python/paddle_serving_app/reader/image_reader.py
index cfd50e2514ae796af06d3301fc728bf0f5a88ad0..4f747df1f74800cf692bb22171466bffb7c598b0 100644
--- a/python/paddle_serving_app/reader/image_reader.py
+++ b/python/paddle_serving_app/reader/image_reader.py
@@ -517,6 +517,19 @@ class BGR2RGB(object):
         return self.__class__.__name__ + "()"
 
 
+class String2Image(object):
+    def __init__(self):
+        pass
+
+    def __call__(self, img_buffer):
+        data = np.fromstring(img_buffer, np.uint8)
+        img = cv2.imdecode(data, cv2.IMREAD_COLOR)
+        return img
+
+    def __repr__(self):
+        return self.__class__.__name__ + "()"
+
+
 class File2Image(object):
     def __init__(self):
         pass
@@ -561,7 +574,9 @@ class Base64ToImage(object):
         pass
 
     def __call__(self, img_base64):
-        img = base64.b64decode(img_base64)
+        sample = base64.b64decode(img_base64)
+        data = np.fromstring(sample, np.uint8)
+        img = cv2.imdecode(data, cv2.IMREAD_COLOR)
         return img
 
     def __repr__(self):
diff --git a/tools/serving_build.sh b/tools/serving_build.sh
index 498969b9c886a56e298d397808c2da14a38bac85..175f084d3e29ded9005d7a1e7c39da3e001978c8 100644
--- a/tools/serving_build.sh
+++ b/tools/serving_build.sh
@@ -61,7 +61,7 @@ function build_app() {
                   -DPYTHON_LIBRARIES=$PYTHONROOT/lib/libpython2.7.so \
                   -DPYTHON_EXECUTABLE=$PYTHONROOT/bin/python \
                   -DAPP=ON ..
-            rerun "make -j2 >/dev/null" 3 # due to some network reasons, compilation may fail
+            rerun "make -j10 >/dev/null" 3 # due to some network reasons, compilation may fail
             pip install -U python/dist/paddle_serving_app* >/dev/null
             ;;
         *)
@@ -84,7 +84,7 @@ function build_client() {
                   -DPYTHON_LIBRARIES=$PYTHONROOT/lib64/libpython2.7.so \
                   -DPYTHON_EXECUTABLE=$PYTHONROOT/bin/python \
                   -DCLIENT=ON ..
-            rerun "make -j2 >/dev/null" 3 # due to some network reasons, compilation may fail
+            rerun "make -j10 >/dev/null" 3 # due to some network reasons, compilation may fail
             pip install -U python/dist/paddle_serving_client* >/dev/null
             ;;
         *)
@@ -108,7 +108,7 @@ function build_server() {
                   -DPYTHON_LIBRARIES=$PYTHONROOT/lib64/libpython2.7.so \
                   -DPYTHON_EXECUTABLE=$PYTHONROOT/bin/python \
                   -DSERVER=ON ..
-            rerun "make -j2 >/dev/null" 3 # due to some network reasons, compilation may fail
+            rerun "make -j10 >/dev/null" 3 # due to some network reasons, compilation may fail
             check_cmd "make install -j2 >/dev/null"
             pip install -U python/dist/paddle_serving_server* >/dev/null
             ;;
@@ -118,7 +118,7 @@ function build_server() {
                   -DPYTHON_EXECUTABLE=$PYTHONROOT/bin/python \
                   -DSERVER=ON \
                   -DWITH_GPU=ON ..
-            rerun "make -j2 >/dev/null" 3 # due to some network reasons, compilation may fail
+            rerun "make -j10 >/dev/null" 3 # due to some network reasons, compilation may fail
             check_cmd "make install -j2 >/dev/null"
             pip install -U python/dist/paddle_serving_server* >/dev/null
             ;;
@@ -643,13 +643,7 @@ function python_test_yolov4(){
     cd yolov4
     case $TYPE in
         CPU)
-            python -m paddle_serving_app.package --get_model yolov4
-            tar -xzvf yolov4.tar.gz
-            check_cmd "python -m paddle_serving_server.serve --model yolov4_model/ --port 9393 &"
-            sleep 5
-            check_cmd "python test_client.py 000000570688.jpg"
-            echo "yolov4 CPU RPC inference pass"
-            kill_server_process
+            echo "no implement for cpu type"
             ;;
         GPU)
             python -m paddle_serving_app.package --get_model yolov4
@@ -670,6 +664,53 @@ function python_test_yolov4(){
     cd ..
 }
 
+function python_test_resnet50(){
+    #pwd:/ Serving/python/examples
+    local TYPE=$1
+    export SERVING_BIN=${SERVING_WORKDIR}/build-server-${TYPE}/core/general-server/serving
+    cd imagenet
+    case $TYPE in
+        CPU)
+            echo "no implement for cpu type"
+            ;;
+        GPU)
+            sh get_model.sh
+            check_cmd"python -m paddle_serving_server_gpu.serve --model ResNet50_vd_model --port 9696 --gpu_ids 0"
+            sleep 5
+            check_cmd"python resnet50_rpc_client.py ResNet50_vd_client_config/serving_client_conf.prototxt"
+            echo "resnet50 GPU RPC inference pass"
+            kill_server_process
+            ;;
+        *)
+            echo "error type"
+            exit 1
+            ;;
+    esac
+    echo "test resnet $TYPE finished as expected"
+    unset SERVING_BIN
+    cd ..
+}
+
+function python_app_api_test(){
+    #pwd:/ Serving/python/examples
+    #test image reader
+    local TYPE=$1
+    cd imagenet
+    case $TYPE in
+        CPU)
+            check_cmd "python test_image_reader.py"
+            ;;
+        GPU)
+            echo "no implement for cpu type"
+            ;;
+        *)
+            echo "error type"
+            exit 1
+            ;;
+    esac
+    echo "test app api finised as expected"
+    cd ..
+}
 
 function python_run_test() {
     # Using the compiled binary
@@ -684,6 +725,7 @@ function python_run_test() {
     python_test_multi_fetch $TYPE # pwd: /Serving/python/examples
     python_test_yolov4 $TYPE # pwd: /Serving/python/examples
     python_test_grpc_impl $TYPE # pwd: /Serving/python/examples
+    python_test_resnet50 $TYPE # pwd: /Serving/python/examples
     echo "test python $TYPE part finished as expected."
     cd ../.. # pwd: /Serving
 }