def evaluate(self, conf, carray, issame, nrof_folds = 5, tta = False):
self.model.eval()
idx = 0
embeddings = np.zeros([len(carray), conf.embedding_size])
with torch.no_grad():
while idx + conf.batch_size <= len(carray):
batch = torch.tensor(carray[idx:idx + conf.batch_size])
if tta:
fliped = hflip_batch(batch)
emb_batch = self.model(batch.to(conf.device)) + self.model(fliped.to(conf.device))
embeddings[idx:idx + conf.batch_size] = l2_norm(emb_batch)
else:
embeddings[idx:idx + conf.batch_size] = self.model(batch.to(conf.device)).cpu()
idx += conf.batch_size
if idx < len(carray):
batch = torch.tensor(carray[idx:])
if tta:
fliped = hflip_batch(batch)
emb_batch = self.model(batch.to(conf.device)) + self.model(fliped.to(conf.device))
embeddings[idx:] = l2_norm(emb_batch)
else:
embeddings[idx:] = self.model(batch.to(conf.device)).cpu()
tpr, fpr, accuracy, best_thresholds = evaluate(embeddings, issame, nrof_folds)
buf = gen_plot(fpr, tpr)
roc_curve = Image.open(buf)
roc_curve_tensor = trans.ToTensor()(roc_curve)
return accuracy.mean(), best_thresholds.mean(), roc_curve_tensor
def infer(self, conf, faces, target_embs, tta=False):
'''
faces : list of PIL Image
target_embs : [n, 512] computed embeddings of faces in facebank
names : recorded names of faces in facebank
tta : test time augmentation (hfilp, that's all)
'''
embs = []
for img in faces:
if tta:
mirror = trans.functional.hflip(img)
emb = self.model(
conf.test_transform(img).to(conf.device).unsqueeze(0))
emb_mirror = self.model(
conf.test_transform(mirror).to(conf.device).unsqueeze(0))
embs.append(l2_norm(emb + emb_mirror))
else:
embs.append(
self.model(
conf.test_transform(img).to(conf.device).unsqueeze(0)))
source_embs = torch.cat(embs)
diff = source_embs.unsqueeze(-1) - target_embs.transpose(
1, 0).unsqueeze(0)
dist = torch.sum(torch.pow(diff, 2), dim=1)
minimum, min_idx = torch.min(dist, dim=1)
min_idx[minimum > self.threshold] = -1 # if no match, set idx to -1
return min_idx, minimum