fast-reid/fastreid/modeling/heads/bnneck_head.py

47 lines
1.4 KiB
Python

# encoding: utf-8
"""
@author: liaoxingyu
@contact: sherlockliao01@gmail.com
"""
from torch import nn
from .build import REID_HEADS_REGISTRY
from .linear_head import LinearHead
from ..model_utils import weights_init_classifier, weights_init_kaiming
from ...layers import bn_no_bias, Flatten
@REID_HEADS_REGISTRY.register()
class BNneckHead(nn.Module):
def __init__(self, cfg, in_feat, pool_layer=nn.AdaptiveAvgPool2d(1)):
super().__init__()
self._num_classes = cfg.MODEL.HEADS.NUM_CLASSES
self.pool_layer = nn.Sequential(
pool_layer,
Flatten()
)
self.bnneck = bn_no_bias(in_feat)
self.bnneck.apply(weights_init_kaiming)
self.classifier = nn.Linear(in_feat, self._num_classes, bias=False)
self.classifier.apply(weights_init_classifier)
def forward(self, features, targets=None):
"""
See :class:`ReIDHeads.forward`.
"""
global_feat = self.pool_layer(features)
bn_feat = self.bnneck(global_feat)
if not self.training:
return bn_feat
# training
pred_class_logits = self.classifier(bn_feat)
return pred_class_logits, global_feat
@classmethod
def losses(cls, cfg, pred_class_logits, global_features, gt_classes, prefix='') -> dict:
return LinearHead.losses(cfg, pred_class_logits, global_features, gt_classes, prefix)