lcnn/models/base/backbone_factory.py

from libs.vision_libs.models._utils import _ovewrite_value_param, handle_legacy_interface
from libs.vision_libs.models.resnet import resnet50, ResNet50_Weights
from libs.vision_libs.models.detection._utils import overwrite_eps
from libs.vision_libs.models.detection.backbone_utils import _resnet_fpn_extractor, _validate_trainable_layers
from libs.vision_libs.ops import misc as misc_nn_ops
from torch import nn


def get_resnet50_fpn():
    is_trained = False
    trainable_backbone_layers = _validate_trainable_layers(is_trained, None, 5, 3)
    norm_layer = misc_nn_ops.FrozenBatchNorm2d if is_trained else nn.BatchNorm2d
    backbone = resnet50(weights=None, progress=True, norm_layer=norm_layer)
    backbone = _resnet_fpn_extractor(backbone, trainable_backbone_layers)
    return backbone