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| import os | |
| import torch | |
| from torch import nn | |
| from model_irse import Backbone | |
| class IDLoss(nn.Module): | |
| def __init__(self, base_dir='./', device='cuda', ckpt_dict=None): | |
| super(IDLoss, self).__init__() | |
| print('Loading ResNet ArcFace') | |
| self.facenet = Backbone(input_size=112, num_layers=50, drop_ratio=0.6, mode='ir_se').to(device) | |
| if ckpt_dict is None: | |
| self.facenet.load_state_dict(torch.load(os.path.join(base_dir, 'weights', 'model_ir_se50.pth'), map_location=torch.device('cpu'))) | |
| else: | |
| self.facenet.load_state_dict(ckpt_dict) | |
| self.face_pool = torch.nn.AdaptiveAvgPool2d((112, 112)) | |
| self.facenet.eval() | |
| def extract_feats(self, x): | |
| _, _, h, w = x.shape | |
| assert h==w | |
| ss = h//256 | |
| x = x[:, :, 35*ss:-33*ss, 32*ss:-36*ss] # Crop interesting region | |
| x = self.face_pool(x) | |
| x_feats = self.facenet(x) | |
| return x_feats | |
| def forward(self, y_hat, y, x): | |
| n_samples = x.shape[0] | |
| x_feats = self.extract_feats(x) | |
| y_feats = self.extract_feats(y) # Otherwise use the feature from there | |
| y_hat_feats = self.extract_feats(y_hat) | |
| y_feats = y_feats.detach() | |
| loss = 0 | |
| sim_improvement = 0 | |
| id_logs = [] | |
| count = 0 | |
| for i in range(n_samples): | |
| diff_target = y_hat_feats[i].dot(y_feats[i]) | |
| diff_input = y_hat_feats[i].dot(x_feats[i]) | |
| diff_views = y_feats[i].dot(x_feats[i]) | |
| id_logs.append({'diff_target': float(diff_target), | |
| 'diff_input': float(diff_input), | |
| 'diff_views': float(diff_views)}) | |
| loss += 1 - diff_target | |
| id_diff = float(diff_target) - float(diff_views) | |
| sim_improvement += id_diff | |
| count += 1 | |
| return loss / count, sim_improvement / count, id_logs | |