mmclassification/mmcls/models/heads/multi_label_linear_head.py

61 lines
2.0 KiB
Python

import torch
import torch.nn as nn
import torch.nn.functional as F
from ..builder import HEADS
from ..utils import is_tracing
from .multi_label_head import MultiLabelClsHead
@HEADS.register_module()
class MultiLabelLinearClsHead(MultiLabelClsHead):
"""Linear classification head for multilabel task.
Args:
num_classes (int): Number of categories.
in_channels (int): Number of channels in the input feature map.
loss (dict): Config of classification loss.
init_cfg (dict | optional): The extra init config of layers.
Defaults to use dict(type='Normal', layer='Linear', std=0.01).
"""
def __init__(self,
num_classes,
in_channels,
loss=dict(
type='CrossEntropyLoss',
use_sigmoid=True,
reduction='mean',
loss_weight=1.0),
init_cfg=dict(type='Normal', layer='Linear', std=0.01)):
super(MultiLabelLinearClsHead, self).__init__(
loss=loss, init_cfg=init_cfg)
if num_classes <= 0:
raise ValueError(
f'num_classes={num_classes} must be a positive integer')
self.in_channels = in_channels
self.num_classes = num_classes
self.fc = nn.Linear(self.in_channels, self.num_classes)
def forward_train(self, x, gt_label):
gt_label = gt_label.type_as(x)
cls_score = self.fc(x)
losses = self.loss(cls_score, gt_label)
return losses
def simple_test(self, img):
"""Test without augmentation."""
cls_score = self.fc(img)
if isinstance(cls_score, list):
cls_score = sum(cls_score) / float(len(cls_score))
pred = F.sigmoid(cls_score) if cls_score is not None else None
on_trace = is_tracing()
if torch.onnx.is_in_onnx_export() or on_trace:
return pred
pred = list(pred.detach().cpu().numpy())
return pred