1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
|
"""Modified Olivetti faces dataset.
The original database was available from
http://www.cl.cam.ac.uk/research/dtg/attarchive/facedatabase.html
The version retrieved here comes in MATLAB format from the personal
web page of Sam Roweis:
http://www.cs.nyu.edu/~roweis/
There are ten different images of each of 40 distinct subjects. For some
subjects, the images were taken at different times, varying the lighting,
facial expressions (open / closed eyes, smiling / not smiling) and facial
details (glasses / no glasses). All the images were taken against a dark
homogeneous background with the subjects in an upright, frontal position (with
tolerance for some side movement).
The original dataset consisted of 92 x 112, while the Roweis version
consists of 64x64 images.
"""
# Copyright (c) 2011 David Warde-Farley <wardefar at iro dot umontreal dot ca>
# License: BSD 3 clause
from io import BytesIO
from os.path import exists
from os import makedirs
try:
# Python 2
import urllib2
urlopen = urllib2.urlopen
except ImportError:
# Python 3
import urllib.request
urlopen = urllib.request.urlopen
import numpy as np
from scipy.io.matlab import loadmat
from .base import get_data_home, Bunch
from .base import _pkl_filepath
from ..utils import check_random_state
from ..externals import joblib
DATA_URL = "http://cs.nyu.edu/~roweis/data/olivettifaces.mat"
TARGET_FILENAME = "olivetti.pkz"
# Grab the module-level docstring to use as a description of the
# dataset
MODULE_DOCS = __doc__
def fetch_olivetti_faces(data_home=None, shuffle=False, random_state=0,
download_if_missing=True):
"""Loader for the Olivetti faces data-set from AT&T.
Read more in the :ref:`User Guide <olivetti_faces>`.
Parameters
----------
data_home : optional, default: None
Specify another download and cache folder for the datasets. By default
all scikit learn data is stored in '~/scikit_learn_data' subfolders.
shuffle : boolean, optional
If True the order of the dataset is shuffled to avoid having
images of the same person grouped.
download_if_missing: optional, True by default
If False, raise a IOError if the data is not locally available
instead of trying to download the data from the source site.
random_state : optional, integer or RandomState object
The seed or the random number generator used to shuffle the
data.
Returns
-------
An object with the following attributes:
data : numpy array of shape (400, 4096)
Each row corresponds to a ravelled face image of original size 64 x 64 pixels.
images : numpy array of shape (400, 64, 64)
Each row is a face image corresponding to one of the 40 subjects of the dataset.
target : numpy array of shape (400, )
Labels associated to each face image. Those labels are ranging from
0-39 and correspond to the Subject IDs.
DESCR : string
Description of the modified Olivetti Faces Dataset.
Notes
------
This dataset consists of 10 pictures each of 40 individuals. The original
database was available from (now defunct)
http://www.cl.cam.ac.uk/research/dtg/attarchive/facedatabase.html
The version retrieved here comes in MATLAB format from the personal
web page of Sam Roweis:
http://www.cs.nyu.edu/~roweis/
"""
data_home = get_data_home(data_home=data_home)
if not exists(data_home):
makedirs(data_home)
filepath = _pkl_filepath(data_home, TARGET_FILENAME)
if not exists(filepath):
print('downloading Olivetti faces from %s to %s'
% (DATA_URL, data_home))
fhandle = urlopen(DATA_URL)
buf = BytesIO(fhandle.read())
mfile = loadmat(buf)
faces = mfile['faces'].T.copy()
joblib.dump(faces, filepath, compress=6)
del mfile
else:
faces = joblib.load(filepath)
# We want floating point data, but float32 is enough (there is only
# one byte of precision in the original uint8s anyway)
faces = np.float32(faces)
faces = faces - faces.min()
faces /= faces.max()
faces = faces.reshape((400, 64, 64)).transpose(0, 2, 1)
# 10 images per class, 400 images total, each class is contiguous.
target = np.array([i // 10 for i in range(400)])
if shuffle:
random_state = check_random_state(random_state)
order = random_state.permutation(len(faces))
faces = faces[order]
target = target[order]
return Bunch(data=faces.reshape(len(faces), -1),
images=faces,
target=target,
DESCR=MODULE_DOCS)
|
