Merge pull request #1286 from zchen0211/light_mnist

light version of cnn for MNIST

demo/mnist/light_mnist.py

+# Copyright (c) 2016 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.trainer_config_helpers import *
+
+is_predict = get_config_arg("is_predict", bool, False)
+
+####################Data Configuration ##################
+
+if not is_predict:
+    data_dir = './data/'
+    define_py_data_sources2(
+        train_list=data_dir + 'train.list',
+        test_list=data_dir + 'test.list',
+        module='mnist_provider',
+        obj='process')
+
+######################Algorithm Configuration #############
+settings(batch_size=50, learning_rate=0.001, learning_method=AdamOptimizer())
+
+#######################Network Configuration #############
+
+data_size = 1 * 28 * 28
+label_size = 10
+img = data_layer(name='pixel', size=data_size)
+
+
+# light cnn
+# A shallower cnn model: [CNN, BN, ReLU, Max-Pooling] x4 + FC x1
+# Easier to train for mnist dataset and quite efficient
+# Final performance is close to deeper ones on tasks such as digital and character classification 
+def light_cnn(input_image, num_channels, num_classes):
+    def __light__(ipt,
+                  num_filter=128,
+                  times=1,
+                  conv_filter_size=3,
+                  dropouts=0,
+                  num_channels_=None):
+        return img_conv_group(
+            input=ipt,
+            num_channels=num_channels_,
+            pool_size=2,
+            pool_stride=2,
+            conv_padding=0,
+            conv_num_filter=[num_filter] * times,
+            conv_filter_size=conv_filter_size,
+            conv_act=ReluActivation(),
+            conv_with_batchnorm=True,
+            conv_batchnorm_drop_rate=dropouts,
+            pool_type=MaxPooling())
+
+    tmp = __light__(input_image, num_filter=128, num_channels_=num_channels)
+    tmp = __light__(tmp, num_filter=128)
+    tmp = __light__(tmp, num_filter=128)
+    tmp = __light__(tmp, num_filter=128, conv_filter_size=1)
+
+    tmp = fc_layer(input=tmp, size=num_classes, act=SoftmaxActivation())
+    return tmp
+
+
+predict = light_cnn(input_image=img, num_channels=1, num_classes=label_size)
+
+if not is_predict:
+    lbl = data_layer(name="label", size=label_size)
+    inputs(img, lbl)
+    outputs(classification_cost(input=predict, label=lbl))
+else:
+    outputs(predict)