fast-reid/fastreid/modeling/meta_arch/baseline.py

80 lines
2.8 KiB
Python

# encoding: utf-8
"""
@author: liaoxingyu
@contact: sherlockliao01@gmail.com
"""
import torch
from torch import nn
from fastreid.layers import GeneralizedMeanPoolingP, AdaptiveAvgMaxPool2d
from fastreid.modeling.backbones import build_backbone
from fastreid.modeling.heads import build_reid_heads
from fastreid.modeling.losses import reid_losses
from .build import META_ARCH_REGISTRY
@META_ARCH_REGISTRY.register()
class Baseline(nn.Module):
def __init__(self, cfg):
super().__init__()
self.register_buffer("pixel_mean", torch.Tensor(cfg.MODEL.PIXEL_MEAN).view(1, -1, 1, 1))
self.register_buffer("pixel_std", torch.Tensor(cfg.MODEL.PIXEL_STD).view(1, -1, 1, 1))
self._cfg = cfg
# backbone
self.backbone = build_backbone(cfg)
# head
pool_type = cfg.MODEL.HEADS.POOL_LAYER
if pool_type == 'avgpool': pool_layer = nn.AdaptiveAvgPool2d(1)
elif pool_type == 'maxpool': pool_layer = nn.AdaptiveMaxPool2d(1)
elif pool_type == 'gempool': pool_layer = GeneralizedMeanPoolingP()
elif pool_type == "avgmaxpool": pool_layer = AdaptiveAvgMaxPool2d(1)
elif pool_type == "identity": pool_layer = nn.Identity()
else:
raise KeyError(f"{pool_type} is invalid, please choose from "
f"'avgpool', 'maxpool', 'gempool', 'avgmaxpool' and 'identity'.")
in_feat = cfg.MODEL.HEADS.IN_FEAT
num_classes = cfg.MODEL.HEADS.NUM_CLASSES
self.heads = build_reid_heads(cfg, in_feat, num_classes, pool_layer)
@property
def device(self):
return self.pixel_mean.device
def forward(self, batched_inputs):
if not self.training:
pred_feat = self.inference(batched_inputs)
try:
return pred_feat, batched_inputs["targets"], batched_inputs["camid"]
except KeyError:
return pred_feat
images = self.preprocess_image(batched_inputs)
targets = batched_inputs["targets"].long()
# training
features = self.backbone(images) # (bs, 2048, 16, 8)
return self.heads(features, targets)
def inference(self, batched_inputs):
assert not self.training
images = self.preprocess_image(batched_inputs)
features = self.backbone(images) # (bs, 2048, 16, 8)
pred_feat = self.heads(features)
return pred_feat
def preprocess_image(self, batched_inputs):
"""
Normalize and batch the input images.
"""
# images = [x["images"] for x in batched_inputs]
images = batched_inputs["images"]
images.sub_(self.pixel_mean).div_(self.pixel_std)
return images
def losses(self, outputs):
logits, feat, targets = outputs
return reid_losses(self._cfg, logits, feat, targets)