<s>
meta	O
search	O
(	O
or	O
image	O
search	B-Application
engine	I-Application
)	O
is	O
a	O
type	O
of	O
search	B-Application
engine	I-Application
specialised	O
on	O
finding	O
pictures	O
,	O
images	B-Algorithm
,	O
animations	O
etc	O
.	O
</s>
<s>
Like	O
the	O
text	O
search	O
,	O
image	O
search	O
is	O
an	O
information	B-Library
retrieval	I-Library
system	I-Library
designed	O
to	O
help	O
to	O
find	O
information	O
on	O
the	O
Internet	O
and	O
it	O
allows	O
the	O
user	O
to	O
look	O
for	O
images	B-Algorithm
etc	O
.	O
</s>
<s>
using	O
keywords	O
or	O
search	O
phrases	O
and	O
to	O
receive	O
a	O
set	O
of	O
thumbnail	O
images	B-Algorithm
,	O
sorted	O
by	O
relevancy	O
.	O
</s>
<s>
Specialised	O
search	B-Application
engines	I-Application
,	O
like	O
in	O
the	O
fields	O
of	O
image	O
search	O
,	O
are	O
among	O
the	O
fastest	O
growing	O
search	B-Application
services	I-Application
on	O
the	O
internet	O
.	O
</s>
<s>
The	O
most	O
common	O
search	B-Application
engines	I-Application
today	O
offer	O
image	O
search	O
such	O
as	O
Google	B-Application
,	O
Yahoo	B-Application
or	O
Bing	B-Application
!	I-Application
.	O
</s>
<s>
But	O
most	O
image	O
search	O
works	O
as	O
other	O
search	B-Application
engines	I-Application
.	O
</s>
<s>
The	O
metadata	O
of	O
the	O
image	O
is	O
indexed	O
and	O
stored	O
in	O
a	O
large	O
database	O
and	O
when	O
a	O
search	O
query	B-Library
is	O
performed	O
the	O
image	O
search	B-Application
engine	I-Application
looks	O
up	O
the	O
index	B-Algorithm
,	O
and	O
queries	B-Library
are	O
matched	O
with	O
the	O
stored	O
information	O
.	O
</s>
<s>
The	O
usefulness	O
of	O
an	O
image	O
search	B-Application
engine	I-Application
depends	O
on	O
the	O
relevance	O
of	O
the	O
results	O
it	O
returns	O
,	O
and	O
the	O
ranking	O
algorithms	O
are	O
one	O
of	O
the	O
keys	O
to	O
becoming	O
a	O
big	O
player	O
.	O
</s>
<s>
Some	O
search	B-Application
engines	I-Application
can	O
automatically	O
identify	O
a	O
limited	O
range	O
of	O
visual	O
content	O
,	O
e.g.	O
</s>
<s>
This	O
can	O
be	O
used	O
alone	O
,	O
as	O
in	O
content-based	B-Application
image	I-Application
retrieval	I-Application
,	O
or	O
to	O
augment	O
metadata	O
in	O
an	O
image	O
search	O
.	O
</s>
<s>
When	O
performing	O
a	O
search	O
the	O
user	O
receives	O
a	O
set	O
of	O
thumbnail	O
images	B-Algorithm
,	O
sorted	O
by	O
relevancy	O
.	O
</s>
<s>
Using	O
an	O
advanced	O
search	O
option	O
the	O
user	O
can	O
typically	O
adjust	O
the	O
search	B-Application
criteria	I-Application
to	O
fit	O
their	O
own	O
needs	O
,	O
choosing	O
to	O
search	O
only	O
images	B-Algorithm
or	O
animations	O
,	O
color	O
or	O
black	O
and	O
white	O
,	O
and	O
setting	O
preferences	O
on	O
image	O
size	O
.	O
</s>
