mmselfsup/openselfsup/models/classification.py

75 lines
2.2 KiB
Python

import numpy as np
import torch.nn as nn
from openselfsup.utils import print_log
from . import builder
from .registry import MODELS
from .utils import Sobel
@MODELS.register_module
class Classification(nn.Module):
def __init__(self,
backbone,
with_sobel=False,
head=None,
pretrained=None):
super(Classification, self).__init__()
self.with_sobel = with_sobel
if with_sobel:
self.sobel_layer = Sobel()
self.backbone = builder.build_backbone(backbone)
if head is not None:
self.head = builder.build_head(head)
self.init_weights(pretrained=pretrained)
def init_weights(self, pretrained=None):
if pretrained is not None:
print_log('load model from: {}'.format(pretrained), logger='root')
self.backbone.init_weights(pretrained=pretrained)
self.head.init_weights()
def forward_backbone(self, img):
"""Forward backbone
Returns:
x (tuple): backbone outputs
"""
if self.with_sobel:
img = self.sobel_layer(img)
x = self.backbone(img)
return x
def forward_train(self, img, gt_label, **kwargs):
x = self.forward_backbone(img)
outs = self.head(x)
loss_inputs = (outs, gt_label)
losses = self.head.loss(*loss_inputs)
return losses
def forward_test(self, img, **kwargs):
x = self.forward_backbone(img) # tuple
outs = self.head(x)
keys = ['head{}'.format(i) for i in range(len(outs))]
out_tensors = [out.cpu() for out in outs] # NxC
return dict(zip(keys, out_tensors))
def aug_test(self, imgs):
raise NotImplemented
outs = np.mean([self.head(x) for x in self.forward_backbone(imgs)],
axis=0)
return outs
def forward(self, img, mode='train', **kwargs):
if mode == 'train':
return self.forward_train(img, **kwargs)
elif mode == 'test':
return self.forward_test(img, **kwargs)
elif mode == 'extract':
return self.forward_backbone(img)
else:
raise Exception("No such mode: {}".format(mode))