EfficientDet (TF2)

With EfficientDet, the following tasks are supported:

• dataset_convert

• train

• evaluate

• prune

• inference

• export

These tasks may be invoked from the TAO Toolkit Launcher by following the below convention from command line:

            

            
tao efficientdet_tf2 <sub_task> <args_per_subtask>
        

Where args_per_subtask are the command line arguments required for a given subtask. Each of these sub-tasks are explained in detail below.

EfficientDet expects directories of images for training or validation and annotation JSON files in COCO format. See the Data Annotation Format page for more information about the data format for EfficientDet.

The raw image data and the corresponding annotation file need to be converted to TFRecords before training and evaluation. The dataset_convert tool helps to achieve seamless conversion while providing insight on potential issues in an annotation file. The following sections detail how to use dataset_convert.

Sample Usage of the Dataset Converter Tool

The dataset_convert tool is described below:

            

            
tao efficientdet_tf2 dataset-convert [-h] -e <conversion spec file>
        

Below is a sample for the data conversion spec file. The format of the spec file is YAML with configuration parameters under the scopre of dataset_convert.

            

            
dataset_convert:
  image_dir: '/workspace/tao-experiments/data/raw-data/train2017/'
  annotations_file: '/workspace/tao-experiments/data/raw-data/annotations/instances_train2017.json'
  output_dir: '/workspace/tao-experiments/data'
  tag: 'train'
  num_shards: 256
  include_masks: True
        

The details of each parameter are summarized in the table below:

The following example shows how to use the command:

            

            
tao efficientdet_tf2 dataset_convert -i /path/to/convert.yaml
        

Below is a sample for the EfficientDet spec file. It has 8 major components: data, model, train, evaluate, inference, augment, prune and export config as well as mandatory parameters for the encryption key (key) and results directory (results_dir).

            

            
data:
  loader:
    prefetch_size: 4
    shuffle_file: False
    shuffle_buffer: 10000
    cycle_length: 32
    block_length: 16
  max_instances_per_image: 100
  skip_crowd_during_training: True
  image_size: '512x512'
  num_classes: 91
  train_tfrecords:
    - '/datasets/coco/train-*'
  val_tfrecords:
    - '/datasets/coco/val-*'
  val_json_file: '/datasets/coco/annotations/instances_val2017.json'
train:
  optimizer:
    name: 'sgd'
    momentum: 0.9
  lr_schedule:
    name: 'cosine'
    warmup_epoch: 5
    warmup_init: 0.0001
    learning_rate: 0.2
  amp: True
  checkpoint: "/weights/efficientnet-b0_500.eff"
  num_examples_per_epoch: 100
  moving_average_decay: 0.999
  batch_size: 20
  checkpoint_interval: 5
  l2_weight_decay: 0.00004
  l1_weight_decay: 0.0
  clip_gradients_norm: 10.0
  image_preview: True
  qat: False
  random_seed: 42
  pruned_model_path: ''
  num_epochs: 200
model:
  name: 'efficientdet-d0'
  aspect_ratios: '[(1.0, 1.0), (1.4, 0.7), (0.7, 1.4)]'
  anchor_scale: 4
  min_level: 3
  max_level: 7
  num_scales: 3
  freeze_bn: False
  freeze_blocks: []
augment:
  rand_hflip: True
  random_crop_min_scale: 0.1
  random_crop_max_scale: 2
  auto_color_distortion: False
  auto_translate_xy: False
evaluate:
  batch_size: 8
  num_samples: 5000
  max_detections_per_image: 100
  model_path: ''
export:
  max_batch_size: 8
  dynamic_batch_size: True
  min_score_thresh: 0.4
  model_path: ""
  output_path: ""
inference:
  model_path: ""
  image_dir: ""
  output_dir: ""
  dump_label: False
  batch_size: 1
prune:
  model_path: ""
  normalizer: 'max'
  output_path: ""
  equalization_criterion: 'union'
  granularity: 8
  threshold: 0.5
  min_num_filters: 16
  excluded_layers: []
key: 'nvidia_tlt'
results_dir: '/workspace/results_dir'
        

The format of the spec file is YAML. The top level structure of the spec file is summarized in the table below:

Training Config

The training configuration(train) defines the parameters needed for training, evaluation. Details are summarized in the table below.

The optimizer configuration(train.optimizer) specifies the type and parameters of an optimizer. +———————+——————————————————————————————————-+——————————-+————————————————————————————–+ | Field | Description | Data Type and Constraints | Recommended/Typical Value | +———————+——————————————————————————————————-+——————————-+————————————————————————————–+ | name | Optimizer name (only sgd is supported) | String | ‘sgd’ | +———————+——————————————————————————————————-+——————————-+————————————————————————————–+ | momentum | Momentum | float | 0.9 | +———————+——————————————————————————————————-+——————————-+————————————————————————————–+

The learning rate scheduler configuration(train.lr_schedule) specifies the type and parameters of a learning rate scheduler. +———————+——————————————————————————————————-+——————————-+————————————————————————————–+ | Field | Description | Data Type and Constraints | Recommended/Typical Value | +———————+——————————————————————————————————-+——————————-+————————————————————————————–+ | name | The name of the learning rate scheduler. Available options are cosine and soft_anneal | String | ‘cosine’ | +———————+——————————————————————————————————-+——————————-+————————————————————————————–+ | warmup_epoch | The number of warmup epochs in the learning rate schedule | Unsigned int, positive | – | +———————+——————————————————————————————————-+——————————-+————————————————————————————–+ | warmup_init | The initial learning rate in the warmup period | Float | – | +———————+——————————————————————————————————-+——————————-+————————————————————————————–+ | learning_rate | The maximum learning rate | Float | – | +———————+——————————————————————————————————-+——————————-+————————————————————————————–+

Evaluation Config

The evaluation configuration (evaluate) defines the parameters needed for the evaluation either during training or standalone evaluation. Details are summarized in the table below.

Inference Config

The inference configuration (inference) defines the parameters needed for the standalone inference with the trained .tlt model. Details are summarized in the table below.

Dataset Config

The data configuration (data) specifies the input data source and format. This is used for training, evaluation. A detailed description is summarized in the table below.

The dataloader configuration (data.loader) specifies how batches of data are fed into the model.

Model Config

The model configuration (model) specifies the model structure. A detailed description is summarized in the table below.

Augmentation Config

The augment configuration specifies the image augmentation methods used after preprocessing.

Pruning Config

The prune configuration defines the pruning process for a trained model. A detailed description is summarized in the table below.

Export Config

The export configuration contains the parameters of exporting a .tlt model to .etlt model, which can be used for deployment.

Train the EfficientDet model using this command:

            

            
tao efficientdet_tf2 train [-h] -e <experiment_spec>
                            [--gpus <num_gpus>]
                            [--gpu_index <gpu_index>]
                            [--log_file <log_file_path>]
        

Required Arguments

• -e, --experiment_spec: The experiment specification file to set up the training experiment.

Optional Arguments

• --gpus: The number of GPUs to be used for training in a multi-GPU scenario. The default value is 1.

• --gpu_index: The indices of the GPUs to use for training. This argument can be used when the machine has multiple GPUs installed.

• --log_file: The path to the log file. The default value is stdout.

• -h, --help: Show this help message and exit.

Input Requirement

• Input size: C * W * H (where C = 1 or 3, W >= 128, H >= 128; W, H are multiples of 32)

• Image format: JPG

• Label format: COCO detection

Sample Usage

Here’s an example of the train command:

            

            
tao efficientdet_tf2 train --gpus 2 -e /path/to/spec.yaml
        

To run evaluation with an EfficientDet model, use this command:

            

            
tao efficientdet_tf2 evaluate [-h] -e <experiment_spec>
                               [--gpu_index <gpu_index>]
                               [--log_file <log_file_path>]
        

Required Arguments

• -e, --experiment_spec: The experiment spec file to set up the evaluation experiment. This should be the same as the training specification file.

Optional Arguments

• --gpu_index: The index of the GPU to use for evaluation. This argument can be used when the machine has multiple GPUs installed. Note that evaluation can only run on a single GPU.

• --log_file: The path to the log file. The default value is stdout.

• -h, --help: Show this help message and exit.

Sample Usage

Here’s an example of using the evaluate command:

            

            
tao efficientdet_tf2 evaluate -e /path/to/spec.yaml
        

The inference tool for EfficientDet models can be used to visualize bboxes and generate frame-by- frame KITTI format labels on a directory of images.

            

            
tao efficientdet_tf2 inference [-h] -e <experiment spec file>
                                [--gpu_index <gpu_index>]
                                [--log_file <log_file_path>]
        

Required Arguments

• -e, --experiment_spec: The path to an experiment spec file

Optional Arguments

• --gpu_index: The index of the GPU to run inference on. This argument can be used when the machine has multiple GPUs installed. Note that inference can only run on a single GPU.

• --log_file: The path to the log file. The default value is stdout.

• -h, --help: Show this help message and exit

Sample Usage

Here’s an example of using the inference command:

            

            
tao efficientdet_tf2 inference -e /path/to/spec.yaml
        

Pruning removes parameters from the model to reduce the model size without compromising the integrity of the model itself using the tao efficientdet_tf2 prune command.

The tao efficientdet_tf2 prune command includes these parameters:

            

            
tao efficientdet_tf2 prune [-h] -e <experiment spec file>
                            [--gpu_index <gpu_index>]
                            [--log_file <log_file_path>]
        

Required Arguments

• -e, --experiment_spec: The path to an experiment spec file

Optional Arguments

• --gpu_index: The index of the GPU to run pruning on. This argument can be used when the machine has multiple GPUs installed. Note that inference can only run on a single GPU.

• --log_file: Path to the log file. The default value is stdout.

• -h, --help: Show this help message and exit.

After pruning, the model needs to be retrained. See Re-training the Pruned Model for more details.

Using the Prune Command

Here’s an example of using the tao efficientdet_tf2 prune command:

            

            
tao efficientdet_tf2 prune -e /path/to/spec.yaml
        

Once the model has been pruned, there might be a slight decrease in accuracy because some previously useful weights may have been removed. To regain the accuracy, we recommend that you retrain this pruned model over the same dataset. To do this, use the tao efficientdet_tf2 train command as documented in Training the model, with an updated spec file that points to the newly pruned model as the pretrained model file.

We recommend turning off the regularizer or reducing the weight decay in the training_config for EfficientDet to recover the accuracy when retraining a pruned model. To do this, set the regularizer type to NO_REG as mentioned in the Training config section. All the other parameters may be retained in the spec file from the previous training.

Exporting the model decouples the training process from deployment and allows conversion to TensorRT engines outside the TAO environment. TensorRT engines are specific to each hardware configuration and should be generated for each unique inference environment. The exported model may be used universally across training and deployment hardware. The exported model format is referred to as .etlt. The .etlt model format is also an encrypted model format, and it uses the same key as the .tlt model that it is exported from. This key is required when deploying a model.

Exporting the EfficientDet Model

Here’s an example of the command line arguments of the tao efficientdet_tf2 export command:

            

            
tao efficientdet_tf2 export [-h] -e <path to experiment spec>
                              [--gpu_index <gpu_index>]
                              [--log_file <log_file_path>]
        

Required Arguments

• -e, --experiment_spec: The path to the spec file

Optional Arguments

• --gpu_index: The index of (discrete) GPUs used for exporting the model. You can specify the index of the GPU to run export if the machine has multiple GPUs installed. Note that export can only run on a single GPU.

• --log_file: The path to the log file. The default value is stdout.

• -h, --help: Show this help message and exits.

Sample usage

Here’s a sample command to export an EfficientDet model in INT8 mode.

            

            
tao efficientdet_tf2 export -e /path/to/spec.yaml
        

For TensorRT engine generation, validation, and int8 calibration, refer to the TAO Deploy documentation.

Refer to the Integrating an EfficientDet (TF1/TF2) Model page to learn more about deploying an EfficientDet TF2 model to Deepsteram.