<s>
PNGOUT	B-Application
is	O
a	O
freeware	B-License
command	B-Application
line	I-Application
optimizer	O
for	O
PNG	O
images	O
written	O
by	O
Ken	O
Silverman	O
.	O
</s>
<s>
The	O
transformation	O
is	O
lossless	B-Algorithm
,	O
meaning	O
that	O
the	O
resulting	O
image	O
is	O
visually	O
identical	O
to	O
the	O
source	O
image	O
.	O
</s>
<s>
PNGOUT	B-Application
was	O
also	O
available	O
as	O
a	O
plug-in	B-Application
for	O
the	O
freeware	B-License
image	B-Application
viewer	I-Application
IrfanView	B-Protocol
and	O
can	O
be	O
enabled	O
as	O
an	O
option	O
when	O
saving	O
files	O
.	O
</s>
<s>
It	O
allows	O
editing	O
of	O
various	O
PNGOUT	B-Application
settings	O
via	O
a	O
dialog	O
box	O
.	O
</s>
<s>
PNGOUT	B-Application
integration	O
was	O
removed	O
in	O
IrfanView	B-Protocol
version	O
4.58	O
.	O
</s>
<s>
In	O
2006	O
,	O
a	O
commercial	O
version	O
of	O
PNGOUT	B-Application
with	O
a	O
graphical	B-Application
user	I-Application
interface	I-Application
,	O
known	O
as	O
PNGOUTWin	O
,	O
was	O
released	O
by	O
Ardfry	O
Imaging	O
,	O
a	O
small	O
company	O
Silverman	O
co-founded	O
in	O
2005	O
.	O
</s>
<s>
There	O
is	O
also	O
a	O
freeware	B-License
GUI	B-Application
frontend	O
to	O
PNGOUT	B-Application
available	O
,	O
known	O
as	O
PNGGauntlet	O
.	O
</s>
<s>
The	O
main	O
function	O
of	O
PNGOUT	B-Application
is	O
to	O
reduce	O
the	O
size	O
of	O
image	O
data	O
contained	O
in	O
the	O
IDAT	O
chunk	O
.	O
</s>
<s>
This	O
chunk	O
is	O
compressed	O
using	O
the	O
deflate	B-Algorithm
algorithm	I-Algorithm
.	O
</s>
<s>
Deflate	B-Algorithm
algorithms	O
can	O
vary	O
in	O
speed	O
and	O
compression	B-General_Concept
ratio	I-General_Concept
,	O
with	O
higher	O
compression	O
ratios	O
generally	O
implying	O
lower	O
speed	O
.	O
</s>
<s>
Ken	O
Silverman	O
wrote	O
a	O
deflate	B-Algorithm
compressor	O
for	O
PNGOUT	B-Application
that	O
is	O
slower	O
than	O
the	O
ones	O
used	O
in	O
most	O
graphics	O
software	O
,	O
but	O
produces	O
smaller	O
files	O
.	O
</s>
<s>
PNGOUT	B-Application
also	O
performs	O
automatic	O
bit	O
depth	O
,	O
color	O
,	O
and	O
palette	O
reduction	O
where	O
appropriate	O
.	O
</s>
