mmselfsup/openselfsup/models/odc.py

104 lines
3.5 KiB
Python

import numpy as np
import torch
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 ODC(nn.Module):
def __init__(self,
backbone,
with_sobel=False,
neck=None,
head=None,
memory_bank=None,
pretrained=None):
super(ODC, self).__init__()
self.with_sobel = with_sobel
if with_sobel:
self.sobel_layer = Sobel()
self.backbone = builder.build_backbone(backbone)
self.neck = builder.build_neck(neck)
if head is not None:
self.head = builder.build_head(head)
if memory_bank is not None:
self.memory_bank = builder.build_memory(memory_bank)
self.init_weights(pretrained=pretrained)
# set reweight tensors
self.num_classes = head.num_classes
self.loss_weight = torch.ones((self.num_classes, ),
dtype=torch.float32).cuda()
self.loss_weight /= self.loss_weight.sum()
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.neck.init_weights(init_linear='kaiming')
self.head.init_weights(init_linear='normal')
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, idx, **kwargs):
# forward & backward
x = self.forward_backbone(img)
feature = self.neck(x)
outs = self.head(feature)
if self.memory_bank.label_bank.is_cuda:
loss_inputs = (outs, self.memory_bank.label_bank[idx])
else:
loss_inputs = (outs, self.memory_bank.label_bank[idx.cpu()].cuda())
losses = self.head.loss(*loss_inputs)
# update samples memory
change_ratio = self.memory_bank.update_samples_memory(
idx, feature[0].detach())
losses['change_ratio'] = change_ratio
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 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))
def set_reweight(self, labels=None, reweight_pow=0.5):
if labels is None:
if self.memory_bank.label_bank.is_cuda:
labels = self.memory_bank.label_bank.cpu().numpy()
else:
labels = self.memory_bank.label_bank.numpy()
hist = np.bincount(
labels, minlength=self.num_classes).astype(np.float32)
inv_hist = (1. / (hist + 1e-5))**reweight_pow
weight = inv_hist / inv_hist.sum()
self.loss_weight.copy_(torch.from_numpy(weight))
self.head.criterion = nn.CrossEntropyLoss(weight=self.loss_weight)