test_image_classification.py

#   Copyright (c) 2018 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 __future__ import print_function

import paddle.v2 as paddle
import paddle.fluid as fluid
import contextlib
import math
import sys
import numpy
import unittest


def resnet_cifar10(input, depth=32):
    def conv_bn_layer(input, ch_out, filter_size, stride, padding, act='relu'):
        tmp = fluid.layers.conv2d(
            input=input,
            filter_size=filter_size,
            num_filters=ch_out,
            stride=stride,
            padding=padding,
            act=None,
            bias_attr=False)
        return fluid.layers.batch_norm(input=tmp, act=act)

    def shortcut(input, ch_in, ch_out, stride):
        if ch_in != ch_out:
            return conv_bn_layer(input, ch_out, 1, stride, 0, None)
        else:
            return input

    def basicblock(input, ch_in, ch_out, stride):
        tmp = conv_bn_layer(input, ch_out, 3, stride, 1)
        tmp = conv_bn_layer(tmp, ch_out, 3, 1, 1, act=None)
        short = shortcut(input, ch_in, ch_out, stride)
        return fluid.layers.elementwise_add(x=tmp, y=short, act='relu')

    def layer_warp(block_func, input, ch_in, ch_out, count, stride):
        tmp = block_func(input, ch_in, ch_out, stride)
        for i in range(1, count):
            tmp = block_func(tmp, ch_out, ch_out, 1)
        return tmp

    assert (depth - 2) % 6 == 0
    n = (depth - 2) / 6
    conv1 = conv_bn_layer(
        input=input, ch_out=16, filter_size=3, stride=1, padding=1)
    res1 = layer_warp(basicblock, conv1, 16, 16, n, 1)
    res2 = layer_warp(basicblock, res1, 16, 32, n, 2)
    res3 = layer_warp(basicblock, res2, 32, 64, n, 2)
    pool = fluid.layers.pool2d(
        input=res3, pool_size=8, pool_type='avg', pool_stride=1)
    return pool


def vgg16_bn_drop(input):
    def conv_block(input, num_filter, groups, dropouts):
        return fluid.nets.img_conv_group(
            input=input,
            pool_size=2,
            pool_stride=2,
            conv_num_filter=[num_filter] * groups,
            conv_filter_size=3,
            conv_act='relu',
            conv_with_batchnorm=True,
            conv_batchnorm_drop_rate=dropouts,
            pool_type='max')

    conv1 = conv_block(input, 64, 2, [0.3, 0])
    conv2 = conv_block(conv1, 128, 2, [0.4, 0])
    conv3 = conv_block(conv2, 256, 3, [0.4, 0.4, 0])
    conv4 = conv_block(conv3, 512, 3, [0.4, 0.4, 0])
    conv5 = conv_block(conv4, 512, 3, [0.4, 0.4, 0])

    drop = fluid.layers.dropout(x=conv5, dropout_prob=0.5)
    fc1 = fluid.layers.fc(input=drop, size=512, act=None)
    bn = fluid.layers.batch_norm(input=fc1, act='relu')
    drop2 = fluid.layers.dropout(x=bn, dropout_prob=0.5)
    fc2 = fluid.layers.fc(input=drop2, size=512, act=None)
    return fc2


def train(net_type, use_cuda, save_dirname):
    classdim = 10
    data_shape = [3, 32, 32]

    images = fluid.layers.data(name='pixel', shape=data_shape, dtype='float32')
    label = fluid.layers.data(name='label', shape=[1], dtype='int64')

    if net_type == "vgg":
        print("train vgg net")
        net = vgg16_bn_drop(images)
    elif net_type == "resnet":
        print("train resnet")
        net = resnet_cifar10(images, 32)
    else:
        raise ValueError("%s network is not supported" % net_type)

    predict = fluid.layers.fc(input=net, size=classdim, act='softmax')
    cost = fluid.layers.cross_entropy(input=predict, label=label)
    avg_cost = fluid.layers.mean(cost)
    acc = fluid.layers.accuracy(input=predict, label=label)

    # Test program 
    test_program = fluid.default_main_program().clone()

    optimizer = fluid.optimizer.Adam(learning_rate=0.001)
    optimizer.minimize(avg_cost)

    BATCH_SIZE = 128
    PASS_NUM = 1

    train_reader = paddle.batch(
        paddle.reader.shuffle(
            paddle.dataset.cifar.train10(), buf_size=128 * 10),
        batch_size=BATCH_SIZE)

    test_reader = paddle.batch(
        paddle.dataset.cifar.test10(), batch_size=BATCH_SIZE)

    place = fluid.CUDAPlace(0) if use_cuda else fluid.CPUPlace()
    exe = fluid.Executor(place)
    feeder = fluid.DataFeeder(place=place, feed_list=[images, label])
    exe.run(fluid.default_startup_program())

    loss = 0.0
    for pass_id in range(PASS_NUM):
        for batch_id, data in enumerate(train_reader()):
            exe.run(feed=feeder.feed(data))

            if (batch_id % 10) == 0:
                acc_list = []
                avg_loss_list = []
                for tid, test_data in enumerate(test_reader()):
                    loss_t, acc_t = exe.run(program=test_program,
                                            feed=feeder.feed(test_data),
                                            fetch_list=[avg_cost, acc])
                    if math.isnan(float(loss_t)):
                        sys.exit("got NaN loss, training failed.")
                    acc_list.append(float(acc_t))
                    avg_loss_list.append(float(loss_t))
                    break  # Use 1 segment for speeding up CI

                acc_value = numpy.array(acc_list).mean()
                avg_loss_value = numpy.array(avg_loss_list).mean()

                print(
                    'PassID {0:1}, BatchID {1:04}, Test Loss {2:2.2}, Acc {3:2.2}'.
                    format(pass_id, batch_id + 1,
                           float(avg_loss_value), float(acc_value)))

                if acc_value > 0.01:  # Low threshold for speeding up CI
                    fluid.io.save_inference_model(save_dirname, ["pixel"],
                                                  [predict], exe)
                    return


def infer(use_cuda, save_dirname=None):
    if save_dirname is None:
        return

    place = fluid.CUDAPlace(0) if use_cuda else fluid.CPUPlace()
    exe = fluid.Executor(place)

    # Use fluid.io.load_inference_model to obtain the inference program desc,
    # the feed_target_names (the names of variables that will be feeded 
    # data using feed operators), and the fetch_targets (variables that 
    # we want to obtain data from using fetch operators).
    [inference_program, feed_target_names,
     fetch_targets] = fluid.io.load_inference_model(save_dirname, exe)

    # The input's dimension of conv should be 4-D or 5-D.
    tensor_img = numpy.random.rand(1, 3, 32, 32).astype("float32")

    # Construct feed as a dictionary of {feed_target_name: feed_target_data}
    # and results will contain a list of data corresponding to fetch_targets.
    results = exe.run(inference_program,
                      feed={feed_target_names[0]: tensor_img},
                      fetch_list=fetch_targets)
    print("infer results: ", results[0])


def main(net_type, use_cuda):
    if use_cuda and not fluid.core.is_compiled_with_cuda():
        return

    # Directory for saving the trained model
    save_dirname = "image_classification_" + net_type + ".inference.model"

    train(net_type, use_cuda, save_dirname)
    infer(use_cuda, save_dirname)


class TestImageClassification(unittest.TestCase):
    def test_vgg_cuda(self):
        with self.scope_prog_guard():
            main('vgg', use_cuda=True)

    def test_resnet_cuda(self):
        with self.scope_prog_guard():
            main('resnet', use_cuda=True)

    def test_vgg_cpu(self):
        with self.scope_prog_guard():
            main('vgg', use_cuda=False)

    def test_resnet_cpu(self):
        with self.scope_prog_guard():
            main('resnet', use_cuda=False)

    @contextlib.contextmanager
    def scope_prog_guard(self):
        prog = fluid.Program()
        startup_prog = fluid.Program()
        scope = fluid.core.Scope()
        with fluid.scope_guard(scope):
            with fluid.program_guard(prog, startup_prog):
                yield


if __name__ == '__main__':
    unittest.main()