<s>
A	O
visual	B-General_Concept
search	I-General_Concept
engine	I-General_Concept
is	O
a	O
search	B-Application
engine	I-Application
designed	O
to	O
search	O
for	O
information	O
on	O
the	O
World	O
Wide	O
Web	O
through	O
the	O
input	O
of	O
an	O
image	O
or	O
a	O
search	B-Application
engine	I-Application
with	O
a	O
visual	O
display	O
of	O
the	O
search	B-Application
results	I-Application
.	O
</s>
<s>
This	O
type	O
of	O
search	B-Application
engines	I-Application
is	O
mostly	O
used	O
to	O
search	O
on	O
the	O
mobile	O
Internet	O
through	O
an	O
image	O
of	O
an	O
unknown	O
object	O
(	O
unknown	O
search	O
query	O
)	O
.	O
</s>
<s>
These	O
search	B-Application
engines	I-Application
often	O
use	O
techniques	O
for	O
Content	B-Application
Based	I-Application
Image	I-Application
Retrieval	I-Application
.	O
</s>
<s>
A	O
visual	B-General_Concept
search	I-General_Concept
engine	I-General_Concept
searches	O
images	O
,	O
patterns	O
based	O
on	O
an	O
algorithm	O
which	O
it	O
could	O
recognize	O
and	O
gives	O
relative	O
information	O
based	O
on	O
the	O
selective	O
or	O
apply	O
pattern	O
match	O
technique	O
.	O
</s>
<s>
Depending	O
on	O
the	O
nature	O
of	O
the	O
search	B-Application
engine	I-Application
there	O
are	O
two	O
main	O
groups	O
,	O
those	O
which	O
aim	O
to	O
find	O
visual	O
information	O
and	O
those	O
with	O
a	O
visual	O
display	O
of	O
results	O
.	O
</s>
<s>
An	O
image	B-General_Concept
search	I-General_Concept
engine	I-General_Concept
is	O
a	O
search	B-Application
engine	I-Application
that	O
is	O
designed	O
to	O
find	O
an	O
image	O
.	O
</s>
<s>
Two	O
techniques	O
currently	O
used	O
in	O
image	B-General_Concept
search	I-General_Concept
:	O
</s>
<s>
Search	O
by	O
metadata	O
:	O
Image	B-General_Concept
search	I-General_Concept
is	O
based	O
on	O
comparison	O
of	O
metadata	O
associated	O
with	O
the	O
image	O
as	O
keywords	O
,	O
text	O
,	O
etc	O
..	O
and	O
it	O
is	O
obtained	O
a	O
set	O
of	O
images	O
sorted	O
by	O
relevance	O
.	O
</s>
<s>
Search	O
by	O
example	O
:	O
In	O
this	O
technique	O
,	O
also	O
called	O
reverse	B-General_Concept
image	I-General_Concept
search	I-General_Concept
,	O
the	O
search	B-Application
results	I-Application
are	O
obtained	O
through	O
the	O
comparison	O
between	O
images	O
using	O
content-based	B-Application
image	I-Application
retrieval	I-Application
computer	O
vision	O
techniques	O
.	O
</s>
<s>
A	O
video	O
search	B-Application
engine	I-Application
is	O
a	O
search	B-Application
engine	I-Application
designed	O
to	O
search	O
video	O
on	O
the	O
net	O
.	O
</s>
<s>
An	O
example	O
of	O
this	O
type	O
of	O
search	O
is	O
YouTube	B-General_Concept
.	I-General_Concept
</s>
<s>
These	O
have	O
been	O
used	O
with	O
traditional	O
text-based	O
searchers	O
(	O
keywords	O
/	O
tags	O
)	O
,	O
where	O
the	O
authors	O
of	O
the	O
indexed	B-Application
material	O
,	O
or	O
Internet	O
users	O
,	O
have	O
contributed	O
these	O
tags	O
or	O
keywords	O
.	O
</s>
<s>
Because	O
it	O
is	O
not	O
always	O
effective	O
,	O
it	O
has	O
recently	O
been	O
investigated	O
in	O
the	O
implementation	O
of	O
search	B-Application
engines	I-Application
that	O
combine	O
the	O
search	O
using	O
text	O
with	O
the	O
search	O
compared	O
to	O
2D	O
drawings	O
,	O
3D	O
drawings	O
and	O
3D	O
models	O
.	O
</s>
<s>
Princeton	O
University	O
has	O
developed	O
a	O
search	B-Application
engine	I-Application
that	O
combines	O
all	O
these	O
parameters	O
to	O
perform	O
the	O
search	O
,	O
thus	O
increasing	O
the	O
efficiency	O
of	O
search	O
.	O
</s>
<s>
Also	O
,	O
3DfindIT.com	O
portal	O
provides	O
3D	O
models	O
search	B-Application
engine	I-Application
based	O
on	O
sketch	O
,	O
drawings	O
,	O
text	O
,	O
etc	O
.	O
</s>
<s>
A	O
mobile	O
image	O
searcher	O
is	O
a	O
type	O
of	O
search	B-Application
engine	I-Application
designed	O
exclusively	O
for	O
mobile	O
phones	O
,	O
through	O
which	O
you	O
can	O
find	O
any	O
information	O
on	O
Internet	O
,	O
through	O
an	O
image	O
made	O
with	O
the	O
own	O
mobile	O
phone	O
or	O
using	O
certain	O
words	O
(	O
keywords	O
)	O
.	O
</s>
<s>
Typically	O
,	O
this	O
type	O
of	O
search	B-Application
engine	I-Application
uses	O
techniques	O
of	O
query	B-Application
by	I-Application
example	I-Application
or	O
Image	B-Application
query	I-Application
by	I-Application
example	I-Application
,	O
which	O
use	O
the	O
content	O
,	O
shape	O
,	O
texture	O
and	O
color	O
of	O
the	O
image	O
to	O
compare	O
them	O
in	O
a	O
database	O
and	O
then	O
deliver	O
the	O
approximate	O
results	O
from	O
the	O
query	O
.	O
</s>
