tensorflow+ssd_mobilenet实现目标检测的训练

本文在Ubuntu下使用tensorflow的object detection API来训练自己的数据集。所用模型为ssd_mobilenet，也可以使用其他的模型。当然也可以在windows下训练，代码上没有多大差别，主要是配置环境那里，比较麻烦（windows和linux下都一样麻烦）。

一、配置环境

1. 在GitHub上下载所需的models文件，地址：https://github.com/tensorflow/models。

2. 安装pillow、lxml。Jupyter Notebook和matplotlib这两个我就不说了，肯定早就装好了。

pip install pillow
pip install lxml

3. 编译protobuf，object detection API是使用protobuf来训练模型和配置参数，所以得先编译protobuf，下载地址：https://github.com/google/protobuf/releases

windows的配置参考：https://blog.csdn.net/dy_guox/article/details/79081499

Ubuntu下的配置为：

下载地址 https://github.com/google/protobuf/releases
下载protobuf-all-3.7.0.tar.gz

命令如下：

tar zxvf protobuf-all-3.7.0.tar.gz
cd protobuf-3.7.0/
./autogen.sh
./configure --prefix=/usr/local/protobuf
make

make check 出现错误，不过没事

修改配置文件

（1）vim /etc/profile，添加

　　　　　export PATH=$PATH:/usr/local/protobuf/bin/
　　　　　export PKG_CONFIG_PATH=/usr/local/protobuf/lib/pkgconfig/

　　　　保存执行source /etc/profile
　　　　vim ~/.profile，添加
　　　　　　export PATH=$PATH:/usr/local/protobuf/bin/
　　　　　　export PKG_CONFIG_PATH=/usr/local/protobuf/lib/pkgconfig/ 否则会出现登陆用户找不到protoc命令
（2）配置动态链接库
　　　　vim /etc/ld.so.conf 在新的一行添加
　　　　/usr/local/protobuf/lib
　　　　执行命令 sudo ldconfig

安装完成

执行protoc --version,会出现当前libporoto的版本信息
libprotoc 2.6.1

二、在Ubuntu内先制作好自己的VOC数据集。制作过程如下：

在Ubuntu内制作自己的VOC数据集

三、将样本数据转换为TFRecord格式

1. 新建 train_test_split.py 把xml文件数据集分为了train、test、validation三部分，并存储在Annotations文件夹中，训练验证集占80%，测试集占20%。训练集占训练验证集的80%。代码如下：

import os
import random
import time
import shutil

xmlfilepath=r'./Annotations'
saveBasePath=r"./Annotations"

trainval_percent=0.8
train_percent=0.8
total_xml = os.listdir(xmlfilepath)
num=len(total_xml)
list=range(num)
tv=int(num*trainval_percent)
tr=int(tv*train_percent)
trainval= random.sample(list,tv)
train=random.sample(trainval,tr)
print("train and val size",tv)
print("train size",tr) 

start = time.time()

test_num=0
val_num=0
train_num=0  

for i in list:
    name=total_xml[i]
    if i in trainval:  #train and val set
        if i in train:
            directory="train"
            train_num += 1
            xml_path = os.path.join(os.getcwd(), 'Annotations/{}'.format(directory))
            if(not os.path.exists(xml_path)):
                os.mkdir(xml_path)
            filePath=os.path.join(xmlfilepath,name)
            newfile=os.path.join(saveBasePath,os.path.join(directory,name))
            shutil.copyfile(filePath, newfile)
        else:
            directory="validation"
            xml_path = os.path.join(os.getcwd(), 'Annotations/{}'.format(directory))
            if(not os.path.exists(xml_path)):
                os.mkdir(xml_path)
            val_num += 1
            filePath=os.path.join(xmlfilepath,name)
            newfile=os.path.join(saveBasePath,os.path.join(directory,name))
            shutil.copyfile(filePath, newfile)

    else:
        directory="test"
        xml_path = os.path.join(os.getcwd(), 'Annotations/{}'.format(directory))
        if(not os.path.exists(xml_path)):
                os.mkdir(xml_path)
        test_num += 1
        filePath=os.path.join(xmlfilepath,name)
        newfile=os.path.join(saveBasePath,os.path.join(directory,name))
        shutil.copyfile(filePath, newfile)

end = time.time()
seconds=end-start
print("train total : "+str(train_num))
print("validation total : "+str(val_num))
print("test total : "+str(test_num))
total_num=train_num+val_num+test_num
print("total number : "+str(total_num))
print( "Time taken : {0} seconds".format(seconds))

2. 把xml转换成csv文件，xml_to_csv.py 将生成的csv文件放在 object_detection/data/

import os
import glob
import pandas as pd
import xml.etree.ElementTree as ET 

def xml_to_csv(path):
    xml_list = []
    for xml_file in glob.glob(path + '/*.xml'):
        tree = ET.parse(xml_file)
        root = tree.getroot()

        print(root.find('filename').text)
        for member in root.findall('object'):
            value = (root.find('filename').text,
                int(root.find('size')[0].text),   #width
                int(root.find('size')[1].text),   #height
                member[0].text,
                int(member[4][0].text),
                int(float(member[4][1].text)),
                int(member[4][2].text),
                int(member[4][3].text)
                )
            xml_list.append(value)
    column_name = ['filename', 'width', 'height', 'class', 'xmin', 'ymin', 'xmax', 'ymax']
    xml_df = pd.DataFrame(xml_list, columns=column_name)
    return xml_df      

def main():
    for directory in ['train','test','validation']:
        xml_path = os.path.join(os.getcwd(), 'Annotations/{}'.format(directory))  

        xml_df = xml_to_csv(xml_path)
        # xml_df.to_csv('whsyxt.csv', index=None)
        xml_df.to_csv('/home/z/work/models-master/research/object_detection/data/trafficlight_{}_labels.csv'.format(directory), index=None)
        print('Successfully converted xml to csv.')

main()  

3. 生成tfrecord文件，generate_tfrecord.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Created on Tue Mar  5 15:28:55 2019

@author: z
"""

"""
Usage:
  # From tensorflow/models/
  # Create train data:
  python generate_tfrecord.py --csv_input=data/tv_vehicle_labels.csv  --output_path=train.record
  # Create test data:
  python generate_tfrecord.py --csv_input=data/test_labels.csv  --output_path=test.record
"""

import os
import io
import pandas as pd
import tensorflow as tf

from PIL import Image
from object_detection.utils import dataset_util
from collections import namedtuple, OrderedDict

os.chdir('/home/z/work/models-master/research/')

flags = tf.app.flags
flags.DEFINE_string('csv_input', '', 'Path to the CSV input')
flags.DEFINE_string('output_path', '', 'Path to output TFRecord')
FLAGS = flags.FLAGS

# TO-DO replace this with label map
def class_text_to_int(row_label):
        # 你的所有类别
    if row_label == 'red pedestrian':
            return 1
    else:
        return None

def split(df, group):
    data = namedtuple('data', ['filename', 'object'])
    gb = df.groupby(group)
    return [data(filename, gb.get_group(x)) for filename, x in zip(gb.groups.keys(), gb.groups)]

def create_tf_example(group, path):
    with tf.gfile.GFile(os.path.join(path, '{}'.format(group.filename)), 'rb') as fid:
        encoded_jpg = fid.read()
    encoded_jpg_io = io.BytesIO(encoded_jpg)
    image = Image.open(encoded_jpg_io)
    width, height = image.size

    filename = group.filename.encode('utf8')
    image_format = b'jpg'
    xmins = []
    xmaxs = []
    ymins = []
    ymaxs = []
    classes_text = []
    classes = []

    for index, row in group.object.iterrows():
        xmins.append(row['xmin'] / width)
        xmaxs.append(row['xmax'] / width)
        ymins.append(row['ymin'] / height)
        ymaxs.append(row['ymax'] / height)
        classes_text.append(row['class'].encode('utf8'))
        classes.append(class_text_to_int(row['class']))

    tf_example = tf.train.Example(features=tf.train.Features(feature={
        'image/height': dataset_util.int64_feature(height),
        'image/width': dataset_util.int64_feature(width),
        'image/filename': dataset_util.bytes_feature(filename),
        'image/source_id': dataset_util.bytes_feature(filename),
        'image/encoded': dataset_util.bytes_feature(encoded_jpg),
        'image/format': dataset_util.bytes_feature(image_format),
        'image/object/bbox/xmin': dataset_util.float_list_feature(xmins),
        'image/object/bbox/xmax': dataset_util.float_list_feature(xmaxs),
        'image/object/bbox/ymin': dataset_util.float_list_feature(ymins),
        'image/object/bbox/ymax': dataset_util.float_list_feature(ymaxs),
        'image/object/class/text': dataset_util.bytes_list_feature(classes_text),
        'image/object/class/label': dataset_util.int64_list_feature(classes),
    }))
    return tf_example

def main(_):
    writer = tf.python_io.TFRecordWriter(FLAGS.output_path)
    path = os.path.join(os.getcwd(), 'object_detection/images/voc/VOCdevkit/VOC2018/JPEGImages/')
    examples = pd.read_csv(FLAGS.csv_input)
    grouped = split(examples, 'filename')
    num = 0
    for group in grouped:
        num += 1
        tf_example = create_tf_example(group, path)
        writer.write(tf_example.SerializeToString())
        if (num % 100 == 0):    # 每完成100个转换，打印一次
            print(num)

    writer.close()
    output_path = os.path.join(os.getcwd(), FLAGS.output_path)
    print('Successfully created the TFRecords: {}'.format(output_path))

if __name__ == '__main__':
    tf.app.run()

主要是在 row_label 这里要添加上你标注的类别，字符串 row_label 应于labelImg中标注的名称相同。同样 path 为图片的路径。

cd /home/z/work/models-master/research

python generate_tfrecord.py --csv_input=object_detection/data/trafficlight_train_labels.csv --output_path=object_detection/data/

trafficlight_train.tfrecord

generate_tfrecord.py 需要在research目录下，也就是object_detection的上级目录，因为在脚本中使用了 object_detection.utils，如果在 object_detection 下执行命令会报错（No module named object_detection）。

其实这句命令很好理解，其实就是根据脚本中提供的图片路径，找到图片所在。至于是哪些图片？由csv文件来决定。csv文件主要就是记录图片的名称、类别、以及标记框的坐标。如下图所示：

类似的，我们可以输入如下命令，将验证集和测试集也转换为tfrecord格式。

python generate_tfrecord.py --csv_input=object_detection/data/trafficlight_validation_labels.csv --output_path=object_detection/data/
trafficlight_validation.tfrecord

python generate_tfrecord.py --csv_input=object_detection/data/trafficlight_test_labels.csv --output_path=object_detection/data/
trafficlight_test.tfrecord

四、训练

1. 在object_detection/data文件夹下创建标签分类的配置文件（label_map.txt），需要检测几种目标，将创建几个id，代码如下：

item {
  id: 1    # id 从1开始编号
  name: 'red pedestrian'
}

item {
  id: 2
  name: 'green pedestrian'
}

2. 配置管道配置文件，找到object_detection/samples/config/ssd_mobilenet_v1_coco.config，复制到data文件夹下。修改后的代码如下：

# SSD with Mobilenet v1 configuration for MSCOCO Dataset.
# Users should configure the fine_tune_checkpoint field in the train config as
# well as the label_map_path and input_path fields in the train_input_reader and
# eval_input_reader. Search for "PATH_TO_BE_CONFIGURED" to find the fields that
# should be configured.

model {
  ssd {
    num_classes: 17
    box_coder {
      faster_rcnn_box_coder {
        y_scale: 10.0
        x_scale: 10.0
        height_scale: 5.0
        width_scale: 5.0
      }
    }
    matcher {
      argmax_matcher {
        matched_threshold: 0.5
        unmatched_threshold: 0.5
        ignore_thresholds: false
        negatives_lower_than_unmatched: true
        force_match_for_each_row: true
      }
    }
    similarity_calculator {
      iou_similarity {
      }
    }
    anchor_generator {
      ssd_anchor_generator {
        num_layers: 6
        min_scale: 0.2
        max_scale: 0.95
        aspect_ratios: 1.0
        aspect_ratios: 2.0
        aspect_ratios: 0.5
        aspect_ratios: 3.0
        aspect_ratios: 0.3333
      }
    }
    image_resizer {
      fixed_shape_resizer {
        height: 300
        width: 300
      }
    }
    box_predictor {
      convolutional_box_predictor {
        min_depth: 0
        max_depth: 0
        num_layers_before_predictor: 0
        use_dropout: false
        dropout_keep_probability: 0.8
        kernel_size: 1
        box_code_size: 4
        apply_sigmoid_to_scores: false
        conv_hyperparams {
          activation: RELU_6,
          regularizer {
            l2_regularizer {
              weight: 0.00004
            }
          }
          initializer {
            truncated_normal_initializer {
              stddev: 0.03
              mean: 0.0
            }
          }
          batch_norm {
            train: true,
            scale: true,
            center: true,
            decay: 0.9997,
            epsilon: 0.001,
          }
        }
      }
    }
    feature_extractor {
      type: 'ssd_mobilenet_v1'
      min_depth: 16
      depth_multiplier: 1.0
      conv_hyperparams {
        activation: RELU_6,
        regularizer {
          l2_regularizer {
            weight: 0.00004
          }
        }
        initializer {
          truncated_normal_initializer {
            stddev: 0.03
            mean: 0.0
          }
        }
        batch_norm {
          train: true,
          scale: true,
          center: true,
          decay: 0.9997,
          epsilon: 0.001,
        }
      }
    }
    loss {
      classification_loss {
        weighted_sigmoid {
        }
      }
      localization_loss {
        weighted_smooth_l1 {
        }
      }
      hard_example_miner {
        num_hard_examples: 3000
        iou_threshold: 0.99
        loss_type: CLASSIFICATION
        max_negatives_per_positive: 3
        min_negatives_per_image: 0
      }
      classification_weight: 1.0
      localization_weight: 1.0
    }
    normalize_loss_by_num_matches: true
    post_processing {
      batch_non_max_suppression {
        score_threshold: 1e-8
        iou_threshold: 0.6
        max_detections_per_class: 100
        max_total_detections: 100
      }
      score_converter: SIGMOID
    }
  }
}

train_config: {
  batch_size: 2
  optimizer {
    rms_prop_optimizer: {
      learning_rate: {
        exponential_decay_learning_rate {
          initial_learning_rate: 0.00001
          decay_steps: 800720
          decay_factor: 0.95
        }
      }
      momentum_optimizer_value: 0.9
      decay: 0.9
      epsilon: 1.0
    }
  }

  # Note: The below line limits the training process to 200K steps, which we
  # empirically found to be sufficient enough to train the pets dataset. This
  # effectively bypasses the learning rate schedule (the learning rate will
  # never decay). Remove the below line to train indefinitely.
  num_steps: 6000
  data_augmentation_options {
    random_horizontal_flip {
    }
  }
  data_augmentation_options {
    ssd_random_crop {
    }
  }
}

train_input_reader: {
  tf_record_input_reader {
    input_path: "data/trafficlight_train.tfrecord"
  }
  label_map_path: "data/trafficlight_label_map.pbtxt"
}

eval_config: {
  num_examples: 8000
  # Note: The below line limits the evaluation process to 10 evaluations.
  # Remove the below line to evaluate indefinitely.
  max_evals: 10
}

eval_input_reader: {
  tf_record_input_reader {
    input_path: "data/trafficlight_validation.tfrecord"
  }
  label_map_path: "data/trafficlight_label_map.pbtxt"
  shuffle: false
  num_readers: 1
}

可以修改的有好几处，在代码中都标红了。建议还是将配置文件看一下。主要包括：标注的类别数目、batch_size(建议设置小一点)、学习率和退化率、训练的总步数、训练集和验证集的tfrecord的路径、label_map的路径

3. 开始训练

python train.py --logtostderr --train_dir=training/ --pipeline_config_path=data/ssd_mobilenet_v1_coco.config

参考地址：

https://www.cnblogs.com/White-xzx/p/9503203.html