Files
insightface/src/lfw.py
Jia Guo f16f3fadfa lfw
2017-11-14 22:27:51 +08:00

191 lines
7.9 KiB
Python

"""Helper for evaluation on the Labeled Faces in the Wild dataset
"""
# 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.
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
import os
import numpy as np
from scipy import misc
from sklearn.model_selection import KFold
from scipy import interpolate
import sklearn
from sklearn.decomposition import PCA
#import facenet
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 = KFold(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)
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 = KFold(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))
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 evaluation 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 get_paths(lfw_dir, pairs, file_ext):
nrof_skipped_pairs = 0
path_list = []
issame_list = []
for pair in pairs:
if len(pair) == 3:
path0 = os.path.join(lfw_dir, pair[0], pair[0] + '_' + '%04d' % int(pair[1])+'.'+file_ext)
path1 = os.path.join(lfw_dir, pair[0], pair[0] + '_' + '%04d' % int(pair[2])+'.'+file_ext)
issame = True
elif len(pair) == 4:
path0 = os.path.join(lfw_dir, pair[0], pair[0] + '_' + '%04d' % int(pair[1])+'.'+file_ext)
path1 = os.path.join(lfw_dir, pair[2], pair[2] + '_' + '%04d' % int(pair[3])+'.'+file_ext)
issame = False
if os.path.exists(path0) and os.path.exists(path1): # Only add the pair if both paths exist
path_list += (path0,path1)
issame_list.append(issame)
else:
nrof_skipped_pairs += 1
if nrof_skipped_pairs>0:
print('Skipped %d image pairs' % nrof_skipped_pairs)
return path_list, issame_list
def read_pairs(pairs_filename):
pairs = []
with open(pairs_filename, 'r') as f:
for line in f.readlines()[1:]:
pair = line.strip().split()
pairs.append(pair)
return np.array(pairs)