Caffe学习：使用pycaffe定义网络

使用pycaffe定义网络：

• 参考链接：Learning LeNet

• 引入库：

  import caffe
  
  from caffe import layers as L
  from caffe import params as P

• 使用pycaffe定义Net：

  n = caffe.NetSpec()

• 定义DataLayer：

  n.data, n.label = L.Data(batch_size=batch_size, backend=P.Data.LMDB, source=lmdb, transform_param=dict(scale=1. / 255), ntop=2)
  
  # 效果如下：
  
  layer {
    name: "data"
    type: "Data"
    top: "data"
    top: "label"
    transform_param {
      scale: 0.00392156862745
    }
    data_param {
      source: "mnist/mnist_train_lmdb"
      batch_size: 64
      backend: LMDB
    }
  }
  

• 定义ConvolutionLayer：

  n.conv1 = L.Convolution(n.data, kernel_size=5,
                          num_output=20, weight_filler=dict(type='xavier'))
  
  # 效果如下：
  
  layer {
    name: "conv1"
    type: "Convolution"
    bottom: "data"
    top: "conv1"
    convolution_param {
      num_output: 20
      kernel_size: 5
      weight_filler {
        type: "xavier"
      }
    }
  }

• 定义PoolingLayer：

  n.pool1 = L.Pooling(n.conv1, kernel_size=2,
                      stride=2, pool=P.Pooling.MAX)
  
  # 效果如下：
  
  layer {
    name: "pool1"
    type: "Pooling"
    bottom: "conv1"
    top: "pool1"
    pooling_param {
      pool: MAX
      kernel_size: 2
      stride: 2
    }
  }

• 定义InnerProductLayer：

  n.ip1 = L.InnerProduct(n.pool2, num_output=500,
                         weight_filler=dict(type='xavier'))
  
  # 效果如下：
  
  layer {
    name: "ip1"
    type: "InnerProduct"
    bottom: "pool2"
    top: "ip1"
    inner_product_param {
      num_output: 500
      weight_filler {
        type: "xavier"
      }
    }
  }                   

• 定义ReLULayer：

  n.relu1 = L.ReLU(n.ip1, in_place=True)
  
  # 效果如下：
  
  layer {
    name: "relu1"
    type: "ReLU"
    bottom: "ip1"
    top: "ip1"
  }

• 定义SoftmaxWithLossLayer：

  n.loss = L.SoftmaxWithLoss(n.ip2, n.label)
  
  # 效果如下：
  
  layer {
    name: "loss"
    type: "SoftmaxWithLoss"
    bottom: "ip2"
    bottom: "label"
    top: "loss"
  }

• 定义minst网络：

  import caffe
  
  from caffe import layers as L
  from caffe import params as P
  
  def lenet(lmdb, batch_size):
      n = caffe.NetSpec()
      n.data, n.label = L.Data(batch_size=batch_size,
                               backend=P.Data.LMDB, source=lmdb,
                               transform_param=dict(scale=1. / 255), ntop=2)
      n.conv1 = L.Convolution(n.data, kernel_size=5,
                              num_output=20, weight_filler=dict(type='xavier'))
      n.pool1 = L.Pooling(n.conv1, kernel_size=2,
                          stride=2, pool=P.Pooling.MAX)
      n.conv2 = L.Convolution(n.pool1, kernel_size=5,
                              num_output=50, weight_filler=dict(type='xavier'))
      n.pool2 = L.Pooling(n.conv2, kernel_size=2,
                          stride=2, pool=P.Pooling.MAX)
      n.ip1 = L.InnerProduct(n.pool2, num_output=500,
                             weight_filler=dict(type='xavier'))
      n.relu1 = L.ReLU(n.ip1, in_place=True)
      n.ip2 = L.InnerProduct(n.relu1, num_output=10,
                             weight_filler=dict(type='xavier'))
      n.loss = L.SoftmaxWithLoss(n.ip2, n.label)
  
      return n.to_proto()

• 保存网络定义：

  with open('mnist/lenet_auto_train.prototxt', 'w') as f:
      f.write(str(lenet('mnist/mnist_train_lmdb', 64)))
  with open('mnist/lenet_auto_test.prototxt', 'w') as f:
      f.write(str(lenet('mnist/mnist_test_lmdb', 100)))

• 得lenet_auto_train.prototxt文件如下：（lenet_auto_test.prototxt文件类似）：

  layer { name: "data" type: "Data" top: "data" top: "label" transform_param { scale: 0.00392156862745 }
    data_param { source: "mnist/mnist_train_lmdb" batch_size: 64 backend: LMDB }
  }
  layer { name: "conv1" type: "Convolution" bottom: "data" top: "conv1" convolution_param { num_output: 20 kernel_size: 5 weight_filler { type: "xavier" }
    }
  }
  layer { name: "pool1" type: "Pooling" bottom: "conv1" top: "pool1" pooling_param { pool: MAX kernel_size: 2 stride: 2 }
  }
  layer { name: "conv2" type: "Convolution" bottom: "pool1" top: "conv2" convolution_param { num_output: 50 kernel_size: 5 weight_filler { type: "xavier" }
    }
  }
  layer { name: "pool2" type: "Pooling" bottom: "conv2" top: "pool2" pooling_param { pool: MAX kernel_size: 2 stride: 2 }
  }
  layer { name: "ip1" type: "InnerProduct" bottom: "pool2" top: "ip1" inner_product_param { num_output: 500 weight_filler { type: "xavier" }
    }
  }
  layer { name: "relu1" type: "ReLU" bottom: "ip1" top: "ip1" }
  layer { name: "ip2" type: "InnerProduct" bottom: "ip1" top: "ip2" inner_product_param { num_output: 10 weight_filler { type: "xavier" }
    }
  }
  layer { name: "loss" type: "SoftmaxWithLoss" bottom: "ip2" bottom: "label" top: "loss" }