优化预训练过的Tensorflow API(SSD Mobilenet)的最佳方法

时间:2018-09-25 08:58:28

标签: python python-3.x tensorflow machine-learning tensorflow-datasets

我目前正在微调ssd mobilenet v2模型,以改善人工检测。

我的ssd_mobilenet_v2_coco_config代码为:

# SSD with Mobilenet v2 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: 1
    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: 3
        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_v2'
      min_depth: 16
      depth_multiplier: 1.0
      use_depthwise: true
      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: 3
      }
      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: 24
  optimizer {
    rms_prop_optimizer: {
      learning_rate: {
        exponential_decay_learning_rate {
          initial_learning_rate: 0.004
          decay_steps: 800720
          decay_factor: 0.95
        }
      }
      momentum_optimizer_value: 0.9
      decay: 0.9
      epsilon: 1.0
    }
  }
  fine_tune_checkpoint: "D:/Databases/Coco/cctv/tf/ssd_mobilenet_v2_coco_2018_03_29/model.ckpt"
  fine_tune_checkpoint_type:  "detection"
  # 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: 200000
  data_augmentation_options {
    random_horizontal_flip {
    }
  }
  data_augmentation_options {
    ssd_random_crop {
    }
  }
}

train_input_reader: {
  tf_record_input_reader {
    input_path: "D:/Code/Image/cctvmodel/tfrecordfinalALL/train2.record"
  }
  label_map_path: "D:/Code/Image/cctvmodel/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: "D:/Code/Image/cctvmodel/tfrecordfinalALL/test2.record"
  }
  label_map_path: "D:/Code/Image/cctvmodel/label_map.pbtxt"
  shuffle: false
  num_readers: 1
}

已配置该配置文件以进行再培训。要运行配置文件,请使用以下代码:

(tensorflow) c:\models-master\research>python object_detection/legacy/train.py --logtostderr --train_dir=training/model2/ --pipeline_config_path=training/ssd_mobilenet_v2_2.config

对于微调,我指的是tutorial 1。它指出要对模型进行微调,需要执行以下操作:

1)创建一个对象检测训练pipeline.config文件:从/path/to/pretrainedModels/faster_rcnn_resnet50_lowproposals_coco_2017_11_08/pipeline.config修改一个,只需更改num_classes, fine_tune_checkpoint, num_steps, label_map_path and tf_record_input_reader/input_path.

2)为from_detection_checkpoint设置正确的值。如果要从预先训练的对象检测模型中进行微调,请将其设置为true;否则,将其设置为true。如果来自分类预训练模型,则将其设置为false。

3)使用以下命令进行训练:

From the tensorflow/models/research/ directory
python object_detection/train.py \
--logtostderr \
--train_dir=${PATH_TO_TRAIN_DIR} \
--pipeline_config_path=${PATH_TO_YOUR_PIPELINE_CONFIG}

我注意到许多教程与上面列出的教程非常相似。但是,该指令似乎没有充分举例说明最佳微调过程。如果不得不考虑如何在Keras中进行微调,那么它安静而灵活且精心设计。

例如,如何状态化需要冻结的层并指定应训练层的哪些子集。另外,由于型号不同,这是SSD移动网络v2的最佳条件。在大多数情况下,上层是冻结的,后五层是微调的。

也就是说,我们是否要添加一个辍学层等。但是,如何使用配置文件来实现这一点。

需要设置哪些其他参数来优化微调?

也就是说,还有另一个示例可以通过python笔记本tutorial 3进行微调。哪种方法最合适?

0 个答案:

没有答案