def build_model(model_name: Text, inputs: tf.Tensor, **kwargs): """Build model for a given model name. Args: model_name: the name of the model. inputs: an image tensor or a numpy array. **kwargs: extra parameters for model builder. Returns: (cls_outputs, box_outputs): the outputs for class and box predictions. Each is a dictionary with key as feature level and value as predictions. """ mixed_precision = kwargs.get('mixed_precision', None) precision = utils.get_precision(kwargs.get('strategy', None), mixed_precision) if kwargs.get('use_keras_model', None): def model_arch(feats, model_name=None, **kwargs): """Construct a model arch for keras models.""" config = hparams_config.get_efficientdet_config(model_name) config.override(kwargs) model = efficientdet_keras.EfficientDetNet(config=config) cls_out_list, box_out_list = model(feats, training=False) # convert the list of model outputs to a dictionary with key=level. assert len(cls_out_list) == config.max_level - config.min_level + 1 assert len(box_out_list) == config.max_level - config.min_level + 1 cls_outputs, box_outputs = {}, {} for i in range(config.min_level, config.max_level + 1): cls_outputs[i] = cls_out_list[i - config.min_level] box_outputs[i] = box_out_list[i - config.min_level] return cls_outputs, box_outputs else: model_arch = det_model_fn.get_model_arch(model_name) cls_outputs, box_outputs = utils.build_model_with_precision( precision, model_arch, inputs, model_name, **kwargs) if mixed_precision: # Post-processing has multiple places with hard-coded float32. # TODO(tanmingxing): Remove them once post-process can adpat to dtypes. cls_outputs = { k: tf.cast(v, tf.float32) for k, v in cls_outputs.items() } box_outputs = { k: tf.cast(v, tf.float32) for k, v in box_outputs.items() } return cls_outputs, box_outputs
def _model_fn(features, labels, mode, params, model, variable_filter_fn=None): """Model definition entry. Args: features: the input image tensor with shape [batch_size, height, width, 3]. The height and width are fixed and equal. labels: the input labels in a dictionary. The labels include class targets and box targets which are dense label maps. The labels are generated from get_input_fn function in data/dataloader.py mode: the mode of TPUEstimator including TRAIN and EVAL. params: the dictionary defines hyperparameters of model. The default settings are in default_hparams function in this file. model: the model outputs class logits and box regression outputs. variable_filter_fn: the filter function that takes trainable_variables and returns the variable list after applying the filter rule. Returns: tpu_spec: the TPUEstimatorSpec to run training, evaluation, or prediction. Raises: RuntimeError: if both ckpt and backbone_ckpt are set. """ is_tpu = params['strategy'] == 'tpu' if params['img_summary_steps']: utils.image('input_image', features, is_tpu) training_hooks = [] params['is_training_bn'] = (mode == tf.estimator.ModeKeys.TRAIN) if params['use_keras_model']: def model_fn(inputs): model = efficientdet_keras.EfficientDetNet( config=hparams_config.Config(params)) cls_out_list, box_out_list = model(inputs, params['is_training_bn']) cls_outputs, box_outputs = {}, {} for i in range(params['min_level'], params['max_level'] + 1): cls_outputs[i] = cls_out_list[i - params['min_level']] box_outputs[i] = box_out_list[i - params['min_level']] return cls_outputs, box_outputs else: model_fn = functools.partial(model, config=hparams_config.Config(params)) precision = utils.get_precision(params['strategy'], params['mixed_precision']) cls_outputs, box_outputs = utils.build_model_with_precision( precision, model_fn, features, params['is_training_bn']) levels = cls_outputs.keys() for level in levels: cls_outputs[level] = tf.cast(cls_outputs[level], tf.float32) box_outputs[level] = tf.cast(box_outputs[level], tf.float32) # Set up training loss and learning rate. update_learning_rate_schedule_parameters(params) global_step = tf.train.get_or_create_global_step() learning_rate = learning_rate_schedule(params, global_step) # cls_loss and box_loss are for logging. only total_loss is optimized. det_loss, cls_loss, box_loss = detection_loss( cls_outputs, box_outputs, labels, params) reg_l2loss = reg_l2_loss(params['weight_decay']) total_loss = det_loss + reg_l2loss if mode == tf.estimator.ModeKeys.TRAIN: utils.scalar('lrn_rate', learning_rate, is_tpu) utils.scalar('trainloss/cls_loss', cls_loss, is_tpu) utils.scalar('trainloss/box_loss', box_loss, is_tpu) utils.scalar('trainloss/det_loss', det_loss, is_tpu) utils.scalar('trainloss/reg_l2_loss', reg_l2loss, is_tpu) utils.scalar('trainloss/loss', total_loss, is_tpu) train_epochs = tf.cast(global_step, tf.float32) / params['steps_per_epoch'] utils.scalar('train_epochs', train_epochs, is_tpu) moving_average_decay = params['moving_average_decay'] if moving_average_decay: ema = tf.train.ExponentialMovingAverage( decay=moving_average_decay, num_updates=global_step) ema_vars = utils.get_ema_vars() if mode == tf.estimator.ModeKeys.TRAIN: if params['optimizer'].lower() == 'sgd': optimizer = tf.train.MomentumOptimizer( learning_rate, momentum=params['momentum']) elif params['optimizer'].lower() == 'adam': optimizer = tf.train.AdamOptimizer(learning_rate) else: raise ValueError('optimizers should be adam or sgd') if is_tpu: optimizer = tf.tpu.CrossShardOptimizer(optimizer) # Batch norm requires update_ops to be added as a train_op dependency. update_ops = tf.get_collection(tf.GraphKeys.UPDATE_OPS) var_list = tf.trainable_variables() if variable_filter_fn: var_list = variable_filter_fn(var_list) if params.get('clip_gradients_norm', None): logging.info('clip gradients norm by %f', params['clip_gradients_norm']) grads_and_vars = optimizer.compute_gradients(total_loss, var_list) with tf.name_scope('clip'): grads = [gv[0] for gv in grads_and_vars] tvars = [gv[1] for gv in grads_and_vars] # First clip each variable's norm, then clip global norm. clip_norm = abs(params['clip_gradients_norm']) clipped_grads = [ tf.clip_by_norm(g, clip_norm) if g is not None else None for g in grads ] clipped_grads, _ = tf.clip_by_global_norm(clipped_grads, clip_norm) utils.scalar('gradient_norm', tf.linalg.global_norm(clipped_grads), is_tpu) grads_and_vars = list(zip(clipped_grads, tvars)) with tf.control_dependencies(update_ops): train_op = optimizer.apply_gradients(grads_and_vars, global_step) else: with tf.control_dependencies(update_ops): train_op = optimizer.minimize( total_loss, global_step, var_list=var_list) if moving_average_decay: with tf.control_dependencies([train_op]): train_op = ema.apply(ema_vars) else: train_op = None eval_metrics = None if mode == tf.estimator.ModeKeys.EVAL: def metric_fn(**kwargs): """Returns a dictionary that has the evaluation metrics.""" if params['nms_configs'].get('pyfunc', True): detections_bs = [] nms_configs = params['nms_configs'] for index in range(kwargs['boxes'].shape[0]): detections = tf.numpy_function( functools.partial(nms_np.per_class_nms, nms_configs=nms_configs), [ kwargs['boxes'][index], kwargs['scores'][index], kwargs['classes'][index], tf.slice(kwargs['image_ids'], [index], [1]), tf.slice(kwargs['image_scales'], [index], [1]), params['num_classes'], nms_configs['max_output_size'], ], tf.float32) detections_bs.append(detections) detections_bs = postprocess.transform_detections( tf.stack(detections_bs)) else: # These two branches should be equivalent, but currently they are not. # TODO(tanmingxing): enable the non_pyfun path after bug fix. nms_boxes, nms_scores, nms_classes, _ = postprocess.per_class_nms( params, kwargs['boxes'], kwargs['scores'], kwargs['classes'], kwargs['image_scales']) img_ids = tf.cast( tf.expand_dims(kwargs['image_ids'], -1), nms_scores.dtype) detections_bs = [ img_ids * tf.ones_like(nms_scores), nms_boxes[:, :, 1], nms_boxes[:, :, 0], nms_boxes[:, :, 3] - nms_boxes[:, :, 1], nms_boxes[:, :, 2] - nms_boxes[:, :, 0], nms_scores, nms_classes, ] detections_bs = tf.stack(detections_bs, axis=-1, name='detnections') if params.get('testdev_dir', None): logging.info('Eval testdev_dir %s', params['testdev_dir']) eval_metric = coco_metric.EvaluationMetric( testdev_dir=params['testdev_dir']) coco_metrics = eval_metric.estimator_metric_fn(detections_bs, tf.zeros([1])) else: logging.info('Eval val with groudtruths %s.', params['val_json_file']) eval_metric = coco_metric.EvaluationMetric( filename=params['val_json_file'], label_map=params['label_map']) coco_metrics = eval_metric.estimator_metric_fn( detections_bs, kwargs['groundtruth_data']) # Add metrics to output. cls_loss = tf.metrics.mean(kwargs['cls_loss_repeat']) box_loss = tf.metrics.mean(kwargs['box_loss_repeat']) output_metrics = { 'cls_loss': cls_loss, 'box_loss': box_loss, } output_metrics.update(coco_metrics) return output_metrics cls_loss_repeat = tf.reshape( tf.tile(tf.expand_dims(cls_loss, 0), [ params['batch_size'], ]), [params['batch_size'], 1]) box_loss_repeat = tf.reshape( tf.tile(tf.expand_dims(box_loss, 0), [ params['batch_size'], ]), [params['batch_size'], 1]) cls_outputs = postprocess.to_list(cls_outputs) box_outputs = postprocess.to_list(box_outputs) params['nms_configs']['max_nms_inputs'] = anchors.MAX_DETECTION_POINTS boxes, scores, classes = postprocess.pre_nms(params, cls_outputs, box_outputs) metric_fn_inputs = { 'cls_loss_repeat': cls_loss_repeat, 'box_loss_repeat': box_loss_repeat, 'image_ids': labels['source_ids'], 'groundtruth_data': labels['groundtruth_data'], 'image_scales': labels['image_scales'], 'boxes': boxes, 'scores': scores, 'classes': classes, } eval_metrics = (metric_fn, metric_fn_inputs) checkpoint = params.get('ckpt') or params.get('backbone_ckpt') if checkpoint and mode == tf.estimator.ModeKeys.TRAIN: # Initialize the model from an EfficientDet or backbone checkpoint. if params.get('ckpt') and params.get('backbone_ckpt'): raise RuntimeError( '--backbone_ckpt and --checkpoint are mutually exclusive') if params.get('backbone_ckpt'): var_scope = params['backbone_name'] + '/' if params['ckpt_var_scope'] is None: # Use backbone name as default checkpoint scope. ckpt_scope = params['backbone_name'] + '/' else: ckpt_scope = params['ckpt_var_scope'] + '/' else: # Load every var in the given checkpoint var_scope = ckpt_scope = '/' def scaffold_fn(): """Loads pretrained model through scaffold function.""" logging.info('restore variables from %s', checkpoint) var_map = utils.get_ckpt_var_map( ckpt_path=checkpoint, ckpt_scope=ckpt_scope, var_scope=var_scope, skip_mismatch=params['skip_mismatch']) tf.train.init_from_checkpoint(checkpoint, var_map) return tf.train.Scaffold() elif mode == tf.estimator.ModeKeys.EVAL and moving_average_decay: def scaffold_fn(): """Load moving average variables for eval.""" logging.info('Load EMA vars with ema_decay=%f', moving_average_decay) restore_vars_dict = ema.variables_to_restore(ema_vars) saver = tf.train.Saver(restore_vars_dict) return tf.train.Scaffold(saver=saver) else: scaffold_fn = None if is_tpu: return tf.estimator.tpu.TPUEstimatorSpec( mode=mode, loss=total_loss, train_op=train_op, eval_metrics=eval_metrics, host_call=utils.get_tpu_host_call(global_step, params), scaffold_fn=scaffold_fn, training_hooks=training_hooks) else: # Profile every 1K steps. if params.get('profile', False): profile_hook = tf.estimator.ProfilerHook( save_steps=1000, output_dir=params['model_dir'], show_memory=True) training_hooks.append(profile_hook) # Report memory allocation if OOM; it will slow down the running. class OomReportingHook(tf.estimator.SessionRunHook): def before_run(self, run_context): return tf.estimator.SessionRunArgs( fetches=[], options=tf.RunOptions(report_tensor_allocations_upon_oom=True)) training_hooks.append(OomReportingHook()) logging_hook = tf.estimator.LoggingTensorHook( { 'step': global_step, 'det_loss': det_loss, 'cls_loss': cls_loss, 'box_loss': box_loss, }, every_n_iter=params.get('iterations_per_loop', 100), ) training_hooks.append(logging_hook) eval_metric_ops = ( eval_metrics[0](**eval_metrics[1]) if eval_metrics else None) return tf.estimator.EstimatorSpec( mode=mode, loss=total_loss, train_op=train_op, eval_metric_ops=eval_metric_ops, scaffold=scaffold_fn() if scaffold_fn else None, training_hooks=training_hooks)