<s>
OpenEXR	B-Application
is	O
a	O
high-dynamic	O
range	O
,	O
multi-channel	O
raster	B-Algorithm
file	O
format	O
,	O
released	O
as	O
an	O
open	O
standard	O
along	O
with	O
a	O
set	O
of	O
software	O
tools	O
created	O
by	O
Industrial	O
Light	O
&	O
Magic	O
(	O
ILM	O
)	O
,	O
under	O
a	O
free	B-License
software	I-License
license	I-License
similar	O
to	O
the	O
BSD	B-Operating_System
license	I-Operating_System
.	O
</s>
<s>
It	O
is	O
notable	O
for	O
supporting	O
multiple	O
channels	B-Algorithm
of	O
potentially	O
different	O
pixel	O
sizes	O
,	O
including	O
32-bit	O
unsigned	O
integer	O
,	O
32-bit	O
and	O
16-bit	O
floating	O
point	O
values	O
,	O
as	O
well	O
as	O
various	O
compression	O
techniques	O
which	O
include	O
lossless	B-Algorithm
and	O
lossy	B-Algorithm
compression	I-Algorithm
algorithms	O
.	O
</s>
<s>
It	O
also	O
has	O
arbitrary	O
channels	B-Algorithm
and	O
encodes	O
multiple	O
points	O
of	O
view	O
such	O
as	O
left	O
-	O
and	O
right-camera	O
images	O
.	O
</s>
<s>
A	O
full	O
technical	O
introduction	O
of	O
the	O
format	O
is	O
available	O
on	O
the	O
OpenEXR	B-Application
website	O
.	O
</s>
<s>
OpenEXR	B-Application
,	O
or	O
EXR	O
for	O
short	O
,	O
is	O
a	O
deep	B-Algorithm
raster	I-Algorithm
format	O
developed	O
by	O
ILM	O
and	O
broadly	O
used	O
in	O
the	O
computer-graphics	O
industry	O
,	O
both	O
visual	O
effects	O
and	O
animation	O
.	O
</s>
<s>
OpenEXR	B-Application
's	O
multi-resolution	O
and	O
arbitrary	O
channel	O
format	O
makes	O
it	O
appealing	O
for	O
compositing	O
,	O
as	O
it	O
alleviates	O
several	O
painful	O
elements	O
of	O
the	O
process	O
.	O
</s>
<s>
Since	O
it	O
can	O
store	O
arbitrary	O
channels	B-Algorithm
—	O
specular	O
,	O
diffuse	O
,	O
alpha	B-Algorithm
,	O
RGB	O
,	O
normals	O
,	O
and	O
various	O
other	O
types	O
—	O
in	O
one	O
file	O
,	O
it	O
takes	O
away	O
the	O
need	O
to	O
store	O
this	O
information	O
in	O
separate	O
files	O
.	O
</s>
<s>
OpenEXR	B-Application
's	O
API	B-Application
makes	O
tools	O
development	O
a	O
relative	O
ease	O
for	O
developers	O
.	O
</s>
<s>
OpenEXR	B-Application
's	O
library	O
allows	O
quick	O
and	O
easy	O
access	O
to	O
the	O
image	O
's	O
attributes	O
such	O
as	O
tiles	O
and	O
channels	B-Algorithm
.	O
</s>
<s>
The	O
OpenEXR	B-Application
library	O
is	O
developed	O
in	O
C++	B-Language
and	O
is	O
available	O
in	O
source	O
format	O
as	O
well	O
as	O
compiled	O
format	O
for	O
Microsoft	B-Application
Windows	I-Application
,	O
macOS	B-Application
and	O
Linux	B-Application
.	O
</s>
<s>
OpenEXR	B-Application
was	O
created	O
by	O
ILM	O
in	O
1999	O
and	O
released	O
to	O
the	O
public	O
in	O
2003	O
along	O
with	O
an	O
open	O
source	O
software	B-Library
library	I-Library
.	O
</s>
<s>
The	O
format	O
has	O
been	O
updated	O
several	O
times	O
,	O
adding	O
support	O
for	O
tiles	O
,	O
mipmaps	B-Data_Structure
,	O
new	O
compression	O
methods	O
,	O
and	O
other	O
features	O
.	O
</s>
<s>
In	O
2007	O
,	O
OpenEXR	B-Application
was	O
honored	O
with	O
an	O
Academy	O
Award	O
for	O
Technical	O
Achievement	O
.	O
</s>
<s>
OpenEXR	B-Application
2.0	O
was	O
released	O
in	O
April	O
2013	O
,	O
extending	O
the	O
format	O
with	O
support	O
for	O
deep	B-Algorithm
image	I-Algorithm
buffers	I-Algorithm
and	O
multiple	O
images	O
embedded	O
in	O
a	O
single	O
file	O
.	O
</s>
<s>
Version	O
2.2	O
,	O
released	O
August	O
2014	O
,	O
added	O
the	O
lossy	B-Algorithm
DWA	O
compression	O
format	O
.	O
</s>
<s>
The	O
OpenEXR	B-Application
software	O
distribution	O
includes	O
:	O
</s>
<s>
OpenEXR	B-Application
has	O
support	O
for	O
color	O
depth	O
using	O
:	O
</s>
<s>
There	O
are	O
three	O
general	O
types	O
of	O
lossless	B-Algorithm
compression	I-Algorithm
built	O
into	O
OpenEXR	B-Application
,	O
with	O
two	O
different	O
methods	O
of	O
Zip	B-General_Concept
compressing	O
.	O
</s>
<s>
For	O
most	O
images	O
without	O
a	O
lot	O
of	O
grain	O
,	O
the	O
two	O
Zip	B-General_Concept
compression	O
methods	O
seem	O
to	O
work	O
best	O
,	O
while	O
the	O
PIZ	O
compression	O
algorithm	O
is	O
better	O
suited	O
to	O
grainy	O
images	O
.	O
</s>
<s>
Run	B-Algorithm
Length	I-Algorithm
Encoding	I-Algorithm
(	O
RLE	O
)	O
This	O
is	O
a	O
basic	O
form	O
of	O
compression	O
that	O
is	O
comparable	O
to	O
that	O
used	O
by	O
standard	O
Targa	O
files	O
.	O
</s>
<s>
Zip	B-General_Concept
(	O
per	O
scanline	B-Algorithm
)	O
deflate	B-Algorithm
compression	O
with	O
zlib	O
wrapper	O
applied	O
to	O
individual	O
scanlines	B-Algorithm
(	O
not	O
based	O
on	O
the	O
ZIP	B-General_Concept
file	I-General_Concept
format	I-General_Concept
despite	O
its	O
name	O
)	O
.	O
</s>
<s>
Zip	B-General_Concept
(	O
16	O
scanline	B-Algorithm
blocks	O
)	O
deflate	B-Algorithm
compression	O
applied	O
to	O
blocks	O
of	O
16	O
scanlines	B-Algorithm
at	O
time	O
.	O
</s>
<s>
PIZ	O
(	O
wavelet	O
compression	O
)	O
This	O
lossless	B-Algorithm
method	O
uses	O
a	O
new	O
combined	O
wavelet	O
/	O
Huffman	B-General_Concept
compression	I-General_Concept
.	O
</s>
<s>
PXR24	O
(	O
24-bit	O
data	O
conversion	O
then	O
deflate	B-Algorithm
compression	O
)	O
This	O
form	O
of	O
compression	O
from	O
Pixar	O
Animation	O
Studios	O
converts	O
32-bit	O
floats	O
to	O
24	O
bits	O
then	O
uses	O
deflate	B-Algorithm
compression	O
.	O
</s>
<s>
It	O
is	O
lossless	B-Algorithm
for	O
half	O
and	O
32-bit	O
integer	O
data	O
and	O
slightly	O
lossy	B-Algorithm
for	O
32-bit	O
float	O
data	O
.	O
</s>
<s>
B44	O
This	O
form	O
of	O
compression	O
is	O
lossy	B-Algorithm
for	O
half	O
data	O
and	O
stores	O
32-bit	O
data	O
uncompressed	O
.	O
</s>
<s>
B44A	O
An	O
extension	O
to	O
B44	O
where	O
areas	O
of	O
flat	O
color	O
are	O
further	O
compressed	O
,	O
such	O
as	O
alpha	B-Algorithm
channels	I-Algorithm
.	O
</s>
<s>
DWAA	O
JPEG-like	O
lossy	B-Algorithm
compression	I-Algorithm
format	O
contributed	O
by	O
DreamWorks	O
Animation	O
.	O
</s>
<s>
Compresses	O
32	O
scanlines	B-Algorithm
together	O
.	O
</s>
<s>
DWAB	O
Same	O
as	O
DWAA	O
,	O
but	O
compresses	O
blocks	O
of	O
256	O
scanlines	B-Algorithm
.	O
</s>
<s>
From	O
org	O
's	O
Technical	O
Introduction	O
:	O
</s>
<s>
The	O
ILM	O
OpenEXR	B-Application
file	O
format	O
was	O
designed	O
and	O
implemented	O
by	O
Florian	O
Kainz	O
,	O
Wojciech	O
Jarosz	O
,	O
and	O
Rod	O
Bogart	O
.	O
</s>
<s>
Drew	O
Hess	O
packaged	O
and	O
adapted	O
ILM	O
's	O
internal	O
source	O
code	O
for	O
public	O
release	O
and	O
maintains	O
the	O
OpenEXR	B-Application
software	O
distribution	O
.	O
</s>
