Add conv layer and layer tests

Reviewed By: xianjiec

Differential Revision: D5569206

fbshipit-source-id: ed836315f3ee4d7983da94f2633a3085fe99194d

Author: Long Jin

caffe2/python/layers/conv.py

@@ -0,0 +1,135 @@
+## @package conv
+# Module caffe2.python.layers.conv
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+from __future__ import unicode_literals
+
+from caffe2.python import schema
+from caffe2.python.layers.layers import (
+    ModelLayer,
+)
+import numpy as np
+
+
+class Conv(ModelLayer):
+    """
+        Convolutional layer
+        Input:
+        - input_record: at least has the shape info of C (num_channels)
+        - output_dim: number of convolutional filters
+        - kernel_h, kernel_w: kernel size for h and w
+        - stride_h, stride_w: stride for h and w
+        - pad_b, pad_l, pad_r, pad_t: padding sizes, if stride == 1,
+                                      'None' value will do auto padding
+        - order: either 'NHWC' or 'NCHW'
+    """
+
+    def __init__(self, model, input_record, output_dim, kernel_h, kernel_w,
+                 stride_h, stride_w, pad_b=None, pad_l=None, pad_r=None,
+                 pad_t=None, order='NHWC', kernel_init=None, bias_init=None,
+                 kernel_optim=None, bias_optim=None,
+                 name='conv', **kwargs):
+
+        super(Conv, self).__init__(model, name, input_record, **kwargs)
+        assert isinstance(input_record, schema.Scalar), "Incorrect input type"
+        # input num_channels (C) is needed
+        input_dims = input_record.field_type().shape
+
+        assert (kernel_h > 0 and isinstance(kernel_h, int)), (
+            "kernel_h should be positive integer")
+        assert (kernel_w > 0 and isinstance(kernel_w, int)), (
+            "kernel_w should be positive integer")
+        self.kernel_h = kernel_h
+        self.kernel_w = kernel_w
+
+        assert (stride_h > 0 and isinstance(stride_h, int)), (
+            "stride_h should be positive integer")
+        assert (stride_w > 0 and isinstance(stride_w, int)), (
+            "stride_w should be positive integer")
+        self.stride_h = stride_h
+        self.stride_w = stride_w
+
+        # output_dim calculation (http://cs231n.github.io/convolutional-networks/)
+        # output_dim_w = (input_dim_w - kernel_w + pad_r + pad_l) / stride_w + 1
+        # so, do auto_padding requires
+        # pad_r, pad_l = [(input_dim_w - 1) * stride_w - input_dim_w + kernel_w] / 2
+        # similair for pad_t and pad_b to auto pad kernel_h
+        # here we only do auto padding for stride = 1 case
+        if stride_h == 1:
+            pad_t = int((kernel_h - 1) / 2) if pad_t is None else pad_t
+            pad_b = int((kernel_h - 1) / 2) if pad_b is None else pad_b
+        else:
+            pad_t = 0 if pad_t is None else pad_t
+            pad_b = 0 if pad_b is None else pad_b
+
+        if stride_w == 1:
+            pad_r = int((kernel_w - 1) / 2) if pad_r is None else pad_r
+            pad_l = int((kernel_w - 1) / 2) if pad_l is None else pad_l
+        else:
+            pad_r = 0 if pad_r is None else pad_r
+            pad_l = 0 if pad_l is None else pad_l
+
+        assert (pad_t >= 0 and isinstance(pad_t, int)), "pad_t should be int >= 0"
+        assert (pad_b >= 0 and isinstance(pad_b, int)), "pad_b should be int >= 0"
+        assert (pad_r >= 0 and isinstance(pad_r, int)), "pad_r should be int >= 0"
+        assert (pad_l >= 0 and isinstance(pad_l, int)), "pad_l should be int >= 0"
+        self.pad_t = pad_t
+        self.pad_b = pad_b
+        self.pad_r = pad_r
+        self.pad_l = pad_l
+
+        assert order in ['NHWC', 'NCHW'], "order should either 'NHWC' or 'NCHW'"
+        self.order = order
+
+        if order == 'NHWC':
+            input_c = input_dims[-1]
+            kernel_shape = [output_dim, kernel_h, kernel_w, input_c]
+        elif order == 'NCHW':
+            input_c = input_dims[0]
+            kernel_shape = [output_dim, input_c, kernel_h, kernel_w]
+        assert input_c > 0, (
+            "Number of input channels in conv parameters should be positive")
+
+        kernel_init = kernel_init if kernel_init else (
+            'XavierFill', {}
+        )
+        bias_init = bias_init if bias_init else (
+            'ConstantFill', {'value': 0.0}
+        )
+
+        self.kernel = self.create_param(
+            param_name='conv_kernel',
+            shape=kernel_shape,
+            initializer=kernel_init,
+            optimizer=kernel_optim,
+        )
+
+        self.bias = self.create_param(
+            param_name='conv_bias',
+            shape=[output_dim],
+            initializer=bias_init,
+            optimizer=bias_optim,
+        )
+
+        # the output_schema only has the num of output channels
+        # output_h and output_w would be inferred internally
+        self.output_schema = schema.Scalar(
+            (np.float32, (output_dim,)),
+            self.get_next_blob_reference('output')
+        )
+
+    def add_ops(self, net):
+        net.Conv(
+            self.input_record.field_blobs() + [self.kernel, self.bias],
+            self.output_schema.field_blobs(),
+            kernel_h=self.kernel_h,
+            kernel_w=self.kernel_w,
+            stride_h=self.stride_h,
+            stride_w=self.stride_w,
+            pad_t=self.pad_t,
+            pad_l=self.pad_l,
+            pad_b=self.pad_b,
+            pad_r=self.pad_r,
+            order=self.order
+        )

caffe2/python/layers_test.py

@@ -1178,3 +1178,76 @@ def _semi_random_hypothesis_test(srf_output, X_full, X_random, rand_w,
         self._test_net(predict_net, ops_list)
         _semi_random_hypothesis_test(srf_output.full(), X_full, X_random,
                                      rand_w, rand_b, s)
+
+    def testConv(self):
+        batch_size = 50
+        H = 1
+        W = 10
+        C = 50
+        output_dims = 32
+        kernel_h = 1
+        kernel_w = 3
+        stride_h = 1
+        stride_w = 1
+        pad_t = 0
+        pad_b = 0
+        pad_r = None
+        pad_l = None
+
+        input_record = self.new_record(schema.Scalar((np.float32, (H, W, C))))
+        X = np.random.random((batch_size, H, W, C)).astype(np.float32)
+        schema.FeedRecord(input_record, [X])
+        conv = self.model.Conv(
+            input_record,
+            output_dims,
+            kernel_h=kernel_h,
+            kernel_w=kernel_w,
+            stride_h=stride_h,
+            stride_w=stride_w,
+            pad_t=pad_t,
+            pad_b=pad_b,
+            pad_r=pad_r,
+            pad_l=pad_l,
+            order='NHWC'
+        )
+
+        self.assertEqual(
+            schema.Scalar((np.float32, (output_dims,))),
+            conv
+        )
+
+        self.run_train_net_forward_only()
+        output_record = schema.FetchRecord(conv)
+        # check the number of output channels is the same as input in this example
+        assert output_record.field_types()[0].shape == (H, W, output_dims)
+        assert output_record().shape == (batch_size, H, W, output_dims)
+
+        train_init_net, train_net = self.get_training_nets()
+        # Init net assertions
+        init_ops = self.assertNetContainOps(
+            train_init_net,
+            [
+                OpSpec("XavierFill", None, None),
+                OpSpec("ConstantFill", None, None),
+            ]
+        )
+        conv_spec = OpSpec(
+            "Conv",
+            [
+                input_record.field_blobs()[0],
+                init_ops[0].output[0],
+                init_ops[1].output[0],
+            ],
+            conv.field_blobs()
+        )
+
+        # Train net assertions
+        self.assertNetContainOps(train_net, [conv_spec])
+
+        # Predict net assertions
+        predict_net = self.get_predict_net()
+        self.assertNetContainOps(predict_net, [conv_spec])
+
+        # Eval net assertions
+        eval_net = self.get_eval_net()
+        self.assertNetContainOps(eval_net, [conv_spec])