<s>
The	O
Xiaomi	B-Application
Mi	I-Application
4	I-Application
(	O
Chinese	O
:	O
小米手机4	O
)	O
is	O
a	O
smartphone	B-Application
developed	O
by	O
the	O
Chinese	O
electronics	O
manufacturer	O
Xiaomi	O
for	O
its	O
high-end	O
smartphone	B-Application
line	O
,	O
and	O
was	O
released	O
in	O
August	O
2014	O
.	O
</s>
<s>
Xiaomi	O
held	O
an	O
event	O
to	O
formally	O
introduce	O
the	O
high-end	O
phone	B-Application
,	O
and	O
its	O
complementary	O
smart-accessory	O
,	O
the	O
Xiaomi	O
MiBand	B-Device
,	O
during	O
the	O
Xiaomi	O
New	O
Product	O
Launch	O
Event	O
2014	O
on	O
22	O
July	O
2014	O
.	O
</s>
<s>
Similar	O
to	O
the	O
principle	O
of	O
the	O
Xiaomi	B-Application
Mi2	I-Application
,	O
the	O
Mi	O
4	O
is	O
a	O
highly	O
revamped	O
version	O
of	O
its	O
predecessor	O
,	O
the	O
Xiaomi	B-Application
Mi3	I-Application
.	O
</s>
<s>
The	O
phone	B-Application
is	O
of	O
a	O
different	O
design	O
to	O
its	O
predecessor	O
.	O
</s>
<s>
It	O
was	O
also	O
released	O
slightly	O
before	O
the	O
new	O
MIUI	B-Protocol
6	O
,	O
which	O
was	O
introduced	O
in	O
August	O
2014	O
.	O
</s>
<s>
Reception	O
towards	O
the	O
device	O
was	O
generally	O
positive	O
,	O
though	O
there	O
were	O
still	O
a	O
high	O
amount	O
of	O
negative	O
feedback	O
from	O
users	O
of	O
Apple	O
's	O
iPhone	B-Device
due	O
to	O
its	O
similar	O
design	O
and	O
quality	O
.	O
</s>
<s>
Some	O
media	O
companies	O
hailed	O
it	O
to	O
be	O
one	O
of	O
the	O
best	O
smartphones	B-Application
available	O
in	O
the	O
market	O
due	O
to	O
its	O
high-end	O
hardware	O
which	O
is	O
sold	O
for	O
a	O
comparably	O
at	O
a	O
lower	O
price	O
compared	O
to	O
competitor	O
smartphones	B-Application
.	O
</s>
<s>
However	O
,	O
others	O
criticized	O
it	O
for	O
being	O
too	O
similar	O
to	O
Apple	O
's	O
iPhone	B-Operating_System
5S	I-Operating_System
.	O
</s>
<s>
Before	O
its	O
official	O
unveiling	O
,	O
media	O
speculation	O
primarily	O
focused	O
on	O
leaks	O
;	O
including	O
photos	O
of	O
the	O
early	O
prototypes	O
of	O
the	O
device	O
and	O
screenshots	O
of	O
MIUI	B-Protocol
6	O
,	O
these	O
leaks	O
were	O
later	O
proven	O
to	O
be	O
fake	O
.	O
</s>
<s>
Xiaomi	O
announced	O
the	O
Mi	O
4	O
and	O
MiBand	B-Device
during	O
a	O
media	O
event	O
at	O
the	O
CNCC	O
on	O
22	O
July	O
2014	O
.	O
</s>
<s>
While	O
the	O
device	O
was	O
announced	O
in	O
July	O
2014	O
,	O
it	O
did	O
n't	O
become	O
available	O
until	O
August	O
2014	O
,	O
shortly	O
before	O
unveiling	O
MIUI	B-Protocol
6	O
.	O
</s>
<s>
The	O
Xiaomi	B-Application
Mi	I-Application
4	I-Application
ships	O
with	O
MIUI	B-Protocol
V5	O
(	O
upgradable	O
to	O
MIUI	B-Protocol
V10	O
)	O
,	O
Xiaomi	O
's	O
variant	O
of	O
the	O
Android	B-Application
operating	I-Application
system	I-Application
.	O
</s>
<s>
The	O
user	B-Application
interface	I-Application
of	O
MIUI	B-Protocol
is	O
based	O
on	O
the	O
concept	O
of	O
direct	O
manipulation	O
,	O
using	O
multi-touch	B-Application
gestures	O
.	O
</s>
<s>
Interface	B-Application
control	O
elements	O
consist	O
of	O
sliders	O
,	O
switches	O
,	O
and	O
buttons	O
.	O
</s>
<s>
Interaction	O
with	O
the	O
OS	B-General_Concept
includes	O
gestures	O
such	O
as	O
swipe	O
,	O
tap	O
,	O
pinch	O
and	O
reverse	O
pinch	O
,	O
all	O
of	O
which	O
have	O
specific	O
definitions	O
within	O
the	O
context	O
of	O
the	O
Android	B-Application
operating	I-Application
system	I-Application
and	O
its	O
multi-touch	B-Application
interface	B-Application
.	O
</s>
<s>
The	O
device	O
includes	O
an	O
updater	O
application	O
that	O
allows	O
it	O
to	O
update	O
its	O
OS	B-General_Concept
to	O
the	O
latest	O
version	O
of	O
MIUI	B-Protocol
available	O
to	O
it	O
.	O
</s>
<s>
In	O
March	O
2015	O
,	O
it	O
was	O
announced	O
that	O
selected	O
registered	O
users	O
of	O
Mi	O
4	O
devices	O
in	O
China	O
would	O
receive	O
a	O
ROM	O
port	O
of	O
the	O
Windows	B-Operating_System
10	I-Operating_System
Mobile	I-Operating_System
operating	B-General_Concept
system	I-General_Concept
as	O
a	O
trial	O
partnership	O
between	O
Xiaomi	O
and	O
Microsoft	O
.	O
</s>
<s>
The	O
device	O
has	O
a	O
5-inch	O
(	O
12.7cm	O
)	O
Sharp/JDI	O
OGS	O
fully	O
laminated	O
touchscreen	B-Device
,	O
with	O
a	O
screen	O
resolution	O
of	O
1080x1920	O
at	O
a	O
pixel	B-Algorithm
density	I-Algorithm
of	O
441ppi	O
.	O
</s>
<s>
The	O
phone	B-Application
itself	O
weighs	O
149	O
grams	O
(	O
5.26oz	O
)	O
and	O
uses	O
a	O
stainless	O
steel	O
frame	O
.	O
</s>
<s>
The	O
Xiaomi	B-Application
Mi	I-Application
4	I-Application
is	O
powered	O
by	O
a	O
Qualcomm	B-Architecture
Snapdragon	I-Architecture
801	O
(	O
MSM8974-AC	O
)	O
chipset	O
,	O
which	O
,	O
at	O
one	O
point	O
made	O
it	O
the	O
fastest	O
Android	B-Application
smartphone	B-Application
to	O
date	O
according	O
to	O
the	O
AnTuTu	O
benchmark	O
application	O
.	O
</s>
<s>
Its	O
processor	O
is	O
a	O
quad-core	B-Architecture
2.5GHz	O
Krait	O
400	O
and	O
its	O
graphics	O
card	O
is	O
an	O
Adreno	O
330	O
.	O
</s>
<s>
The	O
phone	B-Application
includes	O
a	O
3080mAh	O
battery	O
,	O
which	O
provides	O
280	O
hours	O
of	O
standby	O
time	O
.	O
</s>
<s>
The	O
Xiaomi	B-Application
Mi	I-Application
4	I-Application
was	O
announced	O
with	O
a	O
complementary	O
US$12	O
smart	O
accessory	O
known	O
as	O
the	O
Xiaomi	B-Device
Mi	I-Device
Band	I-Device
which	O
is	O
a	O
waterproof	O
sleep-cycle	O
smart	O
alarm	O
,	O
fitness	O
monitor	O
,	O
sleep	O
tracker	O
and	O
remote	O
smartphone	B-Application
unlocker	O
.	O
</s>
<s>
The	O
phone	B-Application
is	O
compatible	O
with	O
CM13	B-Application
,	O
CM14.1	B-Application
and	O
supports	O
true	O
dual-boot	B-Operating_System
.	O
</s>
