Files
insightface/recognition/oneflow_face/validation_util.py
2021-01-20 17:25:35 +08:00

275 lines
9.4 KiB
Python

# MIT License
#
# Copyright (c) 2016 David Sandberg
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
import math
import numpy as np
import sklearn
from sklearn.model_selection import KFold
from sklearn.decomposition import PCA
from scipy import interpolate
class LFold:
def __init__(self, n_splits=2, shuffle=False):
self.n_splits = n_splits
if self.n_splits > 1:
self.k_fold = KFold(n_splits=n_splits, shuffle=shuffle)
def split(self, indices):
if self.n_splits > 1:
return self.k_fold.split(indices)
else:
return [(indices, indices)]
def distance(embeddings1, embeddings2, distance_metric=0):
if distance_metric == 0:
# Euclidian distance
diff = np.subtract(embeddings1, embeddings2)
dist = np.sum(np.square(diff), 1)
elif distance_metric == 1:
# Distance based on cosine similarity
dot = np.sum(np.multiply(embeddings1, embeddings2), axis=1)
norm = np.linalg.norm(embeddings1, axis=1) * np.linalg.norm(
embeddings2, axis=1
)
similarity = dot / norm
dist = np.arccos(similarity) / math.pi
else:
raise "Undefined distance metric %d" % distance_metric
return dist
def calculate_roc(
thresholds, embeddings1, embeddings2, actual_issame, nrof_folds=10, pca=0
):
assert embeddings1.shape[0] == embeddings2.shape[0]
assert embeddings1.shape[1] == embeddings2.shape[1]
nrof_pairs = min(len(actual_issame), embeddings1.shape[0])
nrof_thresholds = len(thresholds)
k_fold = LFold(n_splits=nrof_folds, shuffle=False)
tprs = np.zeros((nrof_folds, nrof_thresholds))
fprs = np.zeros((nrof_folds, nrof_thresholds))
accuracy = np.zeros((nrof_folds))
indices = np.arange(nrof_pairs)
# print('pca', pca)
if pca == 0:
diff = np.subtract(embeddings1, embeddings2)
dist = np.sum(np.square(diff), 1)
for fold_idx, (train_set, test_set) in enumerate(k_fold.split(indices)):
# print('train_set', train_set)
# print('test_set', test_set)
if pca > 0:
print("doing pca on", fold_idx)
embed1_train = embeddings1[train_set]
embed2_train = embeddings2[train_set]
_embed_train = np.concatenate((embed1_train, embed2_train), axis=0)
# print(_embed_train.shape)
pca_model = PCA(n_components=pca)
pca_model.fit(_embed_train)
embed1 = pca_model.transform(embeddings1)
embed2 = pca_model.transform(embeddings2)
embed1 = sklearn.preprocessing.normalize(embed1)
embed2 = sklearn.preprocessing.normalize(embed2)
# print(embed1.shape, embed2.shape)
diff = np.subtract(embed1, embed2)
dist = np.sum(np.square(diff), 1)
# Find the best threshold for the fold
acc_train = np.zeros((nrof_thresholds))
for threshold_idx, threshold in enumerate(thresholds):
_, _, acc_train[threshold_idx] = calculate_accuracy(
threshold, dist[train_set], actual_issame[train_set]
)
best_threshold_index = np.argmax(acc_train)
# print('threshold', thresholds[best_threshold_index])
for threshold_idx, threshold in enumerate(thresholds):
(
tprs[fold_idx, threshold_idx],
fprs[fold_idx, threshold_idx],
_,
) = calculate_accuracy(
threshold, dist[test_set], actual_issame[test_set]
)
_, _, accuracy[fold_idx] = calculate_accuracy(
thresholds[best_threshold_index],
dist[test_set],
actual_issame[test_set],
)
tpr = np.mean(tprs, 0)
fpr = np.mean(fprs, 0)
return tpr, fpr, accuracy
def calculate_accuracy(threshold, dist, actual_issame):
predict_issame = np.less(dist, threshold)
tp = np.sum(np.logical_and(predict_issame, actual_issame))
fp = np.sum(np.logical_and(predict_issame, np.logical_not(actual_issame)))
tn = np.sum(
np.logical_and(
np.logical_not(predict_issame), np.logical_not(actual_issame)
)
)
fn = np.sum(np.logical_and(np.logical_not(predict_issame), actual_issame))
tpr = 0 if (tp + fn == 0) else float(tp) / float(tp + fn)
fpr = 0 if (fp + tn == 0) else float(fp) / float(fp + tn)
acc = float(tp + tn) / dist.size
return tpr, fpr, acc
def calculate_val(
thresholds,
embeddings1,
embeddings2,
actual_issame,
far_target,
nrof_folds=10,
):
assert embeddings1.shape[0] == embeddings2.shape[0]
assert embeddings1.shape[1] == embeddings2.shape[1]
nrof_pairs = min(len(actual_issame), embeddings1.shape[0])
nrof_thresholds = len(thresholds)
k_fold = LFold(n_splits=nrof_folds, shuffle=False)
val = np.zeros(nrof_folds)
far = np.zeros(nrof_folds)
diff = np.subtract(embeddings1, embeddings2)
dist = np.sum(np.square(diff), 1)
indices = np.arange(nrof_pairs)
for fold_idx, (train_set, test_set) in enumerate(k_fold.split(indices)):
# Find the threshold that gives FAR = far_target
far_train = np.zeros(nrof_thresholds)
for threshold_idx, threshold in enumerate(thresholds):
_, far_train[threshold_idx] = calculate_val_far(
threshold, dist[train_set], actual_issame[train_set]
)
if np.max(far_train) >= far_target:
f = interpolate.interp1d(far_train, thresholds, kind="slinear")
threshold = f(far_target)
else:
threshold = 0.0
val[fold_idx], far[fold_idx] = calculate_val_far(
threshold, dist[test_set], actual_issame[test_set]
)
val_mean = np.mean(val)
far_mean = np.mean(far)
val_std = np.std(val)
return val_mean, val_std, far_mean
def calculate_val_far(threshold, dist, actual_issame):
predict_issame = np.less(dist, threshold)
true_accept = np.sum(np.logical_and(predict_issame, actual_issame))
false_accept = np.sum(
np.logical_and(predict_issame, np.logical_not(actual_issame))
)
n_same = np.sum(actual_issame)
n_diff = np.sum(np.logical_not(actual_issame))
# print(true_accept, false_accept)
# print("n_same, n_diff:",n_same, n_diff)
val = float(true_accept) / float(n_same)
far = float(false_accept) / float(n_diff)
return val, far
def evaluate(embeddings, actual_issame, nrof_folds=10, pca=0):
# Calculate metrics
thresholds = np.arange(0, 4, 0.01)
embeddings1 = embeddings[0::2]
embeddings2 = embeddings[1::2]
tpr, fpr, accuracy = calculate_roc(
thresholds,
embeddings1,
embeddings2,
np.asarray(actual_issame),
nrof_folds=nrof_folds,
pca=pca,
)
thresholds = np.arange(0, 4, 0.001)
val, val_std, far = calculate_val(
thresholds,
embeddings1,
embeddings2,
np.asarray(actual_issame),
1e-3,
nrof_folds=nrof_folds,
)
return tpr, fpr, accuracy, val, val_std, far
def cal_validation_metrics(
embeddings_list, issame_list, nrof_folds=10, no_flip=False
):
print("Embedding shape: {}".format(embeddings_list[0].shape))
if no_flip:
embeddings = embeddings_list[0]
print("Reading {} embeddings.".format(len(embeddings)))
embeddings = sklearn.preprocessing.normalize(embeddings)
acc1 = 0.0
std1 = 0.0
_, _, accuracy, val, val_std, far = evaluate(
embeddings, issame_list, nrof_folds=10
)
acc1, std1 = np.mean(accuracy), np.std(accuracy)
print(
"Validation rate: %2.5f+-%2.5f @ FAR=%2.5f" % (val, val_std, far)
)
else:
# xnorm
_xnorm = 0.0
_xnorm_cnt = 0
for embed in embeddings_list:
for i in range(embed.shape[0]):
_em = embed[i]
_norm = np.linalg.norm(_em)
# print(_em.shape, _norm)
_xnorm += _norm
_xnorm_cnt += 1
_xnorm /= _xnorm_cnt
# Evaluate on embeddings
embeddings = embeddings_list[0] + embeddings_list[1]
embeddings = sklearn.preprocessing.normalize(embeddings)
_, _, accuracy, val, val_std, far = evaluate(
embeddings, issame_list, nrof_folds=nrof_folds
)
acc2, std2 = np.mean(accuracy), np.std(accuracy)
print("XNorm: %f" % (_xnorm))
print("Accuracy-Flip: %1.5f+-%1.5f" % (acc2, std2))