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

47 lines
1.7 KiB
Python

# encoding: utf-8
"""
@author: liaoxingyu
@contact: sherlockliao01@gmail.com
"""
from fastreid.layers import *
from fastreid.utils.weight_init import weights_init_classifier
from .build import REID_HEADS_REGISTRY
@REID_HEADS_REGISTRY.register()
class LinearHead(nn.Module):
def __init__(self, cfg, in_feat, num_classes, pool_layer):
super().__init__()
self.pool_layer = pool_layer
# identity classification layer
cls_type = cfg.MODEL.HEADS.CLS_LAYER
if cls_type == 'linear': self.classifier = nn.Linear(in_feat, num_classes, bias=False)
elif cls_type == 'arcSoftmax': self.classifier = ArcSoftmax(cfg, in_feat, num_classes)
elif cls_type == 'circleSoftmax': self.classifier = CircleSoftmax(cfg, in_feat, num_classes)
elif cls_type == 'amSoftmax': self.classifier = AMSoftmax(cfg, in_feat, num_classes)
else:
raise KeyError(f"{cls_type} is invalid, please choose from "
f"'linear', 'arcSoftmax', 'amSoftmax' and 'circleSoftmax'.")
self.classifier.apply(weights_init_classifier)
def forward(self, features, targets=None):
"""
See :class:`ReIDHeads.forward`.
"""
global_feat = self.pool_layer(features)
global_feat = global_feat[..., 0, 0]
# Evaluation
if not self.training: return global_feat
# Training
try: cls_outputs = self.classifier(global_feat)
except TypeError: cls_outputs = self.classifier(global_feat, targets)
pred_class_logits = F.linear(global_feat, self.classifier.weight)
return cls_outputs, pred_class_logits, global_feat