Re: Photoshop Plugin importing as RGB/16 bit

[email protected] Fri, 5 Jun 2009 12:14:14 -0500 (CDT)
Newsgroups gmane.comp.video.openexr.user
Message-ID <1798698712.2263501244222054785.JavaMail.root@mb1>
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Hi Chris,=20
Maybe I didn't explain this well enough. There really is a couple of issues=
 here. So to explain further, I have an EXR file rendered out of 3DStudio i=
n a HDR scene. The scene is a landscape with buildings, hills, and a sky. T=
he hills and buildings have an alpha of 1.0, the sky has an alpha of 0.0. T=
he RGB information is not limited to a 0.0 - 1.0 range... there are some co=
lor values that go up into the 5.0-8.0 range (for example bright reflection=
s on the windows, and the color of the clouds in the sky).=20

If I use the default EXR plugin in CS4 it creates an RGB/32 document, but t=
he sky comes in 100% transparent. This is great if I don't need the sky, bu=
t there is color data for the sky in the EXR file. The sky is blue and ther=
e are white clouds. In After Effects I can alter the way it deals with the =
alpha, and I have the choice to ignore the alpha if I so choose. In Photosh=
op there are no options to do this. The EXR plugin is not the only one that=
 does this. The PNG plugin for example also discards all color data where t=
he alpha is 0.0. The TIFF plugin on the other hand puts the alpha informati=
on into a sepperate channel. I can then choose to use that alpha however I =
wish. Sometimes it's nice to have the alpha pre-composited with the RGB dat=
a the way the PNG/EXR plugin works, but it would also be nice to have an op=
tion somewhere that modifies how Photoshop deals with alpha in an image. I =
would love an option in the main program settings that globally modified ho=
w all image importers dealt with the Alpha.=20

Now if I use the plugin on the OpenEXR website, it brings up a dialog where=
 I can choose to Un-Premultiply, I can change the Gamma, and I can alter th=
e Exposure. It also places the alpha into a sepperate channel like the way =
the TIFF plugin works. I can see my sky and I have my alpha in a sepperate =
channel so that I can do with it what I please. The two problems I have wit=
h this plugin is that; 1) It creates an RGB/16 document instead of a RGB/32=
 which clamps the RGB values and leaves me stuck with the gamma/exposure se=
ttings I selected during import, and 2) There is no 64bit version of the pl=
ugin.=20

To recap, the default EXR plugin needs a user control for how it deals with=
 the alpha, and the OpenEXR plugin needs to open the image as a RGB/32 so t=
hat it does not clamp the color values.=20

I hope this posting is more clear.=20

-Ray=20

----- Original Message -----=20
From: "Chris Cox" <[email protected]>=20
To: [email protected], [email protected]=20
Sent: Thursday, June 4, 2009 6:37:24 PM GMT -08:00 US/Canada Pacific=20
Subject: Re: [Openexr-user] Photoshop Plugin importing as RGB/16 bit=20

Re: [Openexr-user] Photoshop Plugin importing as RGB/16 bit Ray;=20

Photoshop is a straight color application, and OpenEXR is defined as being =
premultiplied. This means that OpenEXR data has to be un-multiplied by the =
transparency/opacity values to work in Photoshop. To a straight color appli=
cation, there is no meaning to color values when the opacity is zero. If th=
e opacity is non-zero, then the color values are there - just un-multiplied=
 so they will composite correctly.=20

Photoshop already handles the EXR =E2=80=9CA=E2=80=9D channel (defined in t=
he spec as opacity/transparency data) correctly =E2=80=93 it opens it as op=
acity/transparency.=20
What the Photoshop EXR plugin does not do is give you a way to open the tra=
nsparency channel as an arbitrary alpha channel, or to open channels other =
than RGBA.=20

I=E2=80=99m sorry I don=E2=80=99t have a solution for you, but your post so=
unded like you were confused about the terminology and what was happening t=
o your data (enough so that I still don=E2=80=99t know what=E2=80=99s not w=
orking for you with the Photoshop EXR plugin).=20

Chris=20



On 6/4/09 4:23 PM, " [email protected] " < [email protected] > wrote:=20



I'm working on a project that is rendering 32bit floating bit EXR files out=
 of 3DStudio. I'm then compiling these frames in After Effects in a 32 bit =
floating point composite and it's all working fine. The problem I'm having =
is that I also need to composite some scenes in Photoshop CS4, and the defa=
ult Photoshop EXR plugin is tossing out any data from the image that has a =
transparent alpha. I found the Photoshop plugin on the OpenEXR website and =
had hopes that it would do what I needed. Thankfully it knows how to handle=
 the alpha channel properly, but unfortunately the plugin imports the image=
 into a 16bit integer document and any value above 1.0 is clipped. I can't =
use the exposure adjustment to access the over bright details. Because of t=
hese import problems I have to run each image through After Effects and do =
the exposure processing there, then export an image to Photoshop.=20

Can the maintainer of the OpenEXR photoshop plugin please recompile a new v=
ersion that imports images into a 32bit document and maintain the full colo=
r range, or provide exposure controls in the plugin? Also, I could use a 64=
bit version of the plugin for the 64bit version of Photoshop.=20

Thanks,=20
Ray Collett=20

--=20
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=20
--=3D=3D-- Ray Collett --=3D=3D--=20
Technical Director; Newlands & Company Inc. www.nc3d.com=20
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=20


_______________________________________________=20
Openexr-user mailing list=20
[email protected]=20
http://lists.nongnu.org/mailman/listinfo/openexr-user=20



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<html><head><style type=3D'text/css'>p { margin: 0; }</style></head><body><=
div style=3D'font-family: Times New Roman; font-size: 12pt; color: #000000'=
>Hi Chris,<br>&nbsp; Maybe I didn't explain this well enough.&nbsp; There r=
eally is a couple of issues here.&nbsp; So to explain further, I have an EX=
R file rendered out of 3DStudio in a HDR scene.&nbsp; The scene is a landsc=
ape with buildings, hills, and a sky.&nbsp; The hills and buildings have an=
 alpha of 1.0, the sky has an alpha of 0.0.&nbsp; The RGB information is no=
t limited to a 0.0 - 1.0 range...&nbsp; there are some color values that go=
 up into the 5.0-8.0 range (for example bright reflections on the windows, =
and the color of the clouds in the sky).<br><br>&nbsp; If I use the default=
 EXR plugin in CS4 it creates an RGB/32 document, but the sky comes in 100%=
 transparent.&nbsp; This is great if I don't need the sky, but there is col=
or data for the sky in the EXR file.&nbsp; The sky is blue and there are wh=
ite clouds.&nbsp; In After Effects I can alter the way it deals with the al=
pha, and I have the choice to ignore the alpha if I so choose. In Photoshop=
 there are no options to do this.&nbsp; The EXR plugin is not the only one =
that does this.&nbsp; The PNG plugin for example also discards all color da=
ta where the alpha is 0.0.&nbsp; The TIFF plugin on the other hand puts the=
 alpha information into a sepperate channel.&nbsp; I can then choose to use=
 that alpha however I wish.&nbsp; Sometimes it's nice to have the alpha pre=
-composited with the RGB data the way the PNG/EXR plugin works, but it woul=
d also be nice to have an option somewhere that modifies how Photoshop deal=
s with alpha in an image.&nbsp; I would love an option in the main program =
settings that globally modified how all image importers dealt with the Alph=
a.<br><br>&nbsp; Now if I use the plugin on the OpenEXR website, it brings =
up a dialog where I can choose to Un-Premultiply, I can change the Gamma, a=
nd I can alter the Exposure.&nbsp; It also places the alpha into a sepperat=
e channel like the way the TIFF plugin works.&nbsp; I can see my sky and I =
have my alpha in a sepperate channel so that I can do with it what I please=
.&nbsp; The two problems I have with this plugin is that; 1) It creates an =
RGB/16 document instead of a RGB/32 which clamps the RGB values and leaves =
me stuck with the gamma/exposure settings I selected during import, and 2) =
There is no 64bit version of the plugin.<br><br>&nbsp; To recap, the defaul=
t EXR plugin needs a user control for how it deals with the alpha, and the =
OpenEXR plugin needs to open the image as a RGB/32 so that it does not clam=
p the color values.<br><br>I hope this posting is more clear.<br><br>-Ray<b=
r><br>----- Original Message -----<br>From: "Chris Cox" &lt;[email protected]&=
gt;<br>To: [email protected], [email protected]<br>Sent: Thursday, June 4,=
 2009 6:37:24 PM GMT -08:00 US/Canada Pacific<br>Subject: Re: [Openexr-user=
] Photoshop Plugin importing as RGB/16 bit<br><br>

<title>Re: [Openexr-user] Photoshop Plugin importing as RGB/16 bit</title>

<font face=3D"Myriad Pro"><span style=3D"font-size: 10pt;">Ray;<br>
<br>
Photoshop is a straight color application, and OpenEXR is defined as being =
premultiplied. &nbsp;This means that OpenEXR data has to be un-multiplied b=
y the transparency/opacity values to work in Photoshop. &nbsp;To a straight=
 color application, there is no meaning to color values when the opacity is=
 zero. &nbsp;If the opacity is non-zero, then the color values are there - =
&nbsp;just un-multiplied so they will composite correctly.<br>
<br>
Photoshop already handles the EXR =E2=80=9CA=E2=80=9D channel (defined in t=
he spec as opacity/transparency data) correctly =E2=80=93 it opens it as op=
acity/transparency.<br>
What the Photoshop EXR plugin does not do is give you a way to open the tra=
nsparency channel as an arbitrary alpha channel, or to open channels other =
than RGBA.<br>
<br>
I=E2=80=99m sorry I don=E2=80=99t have a solution for you, but your post so=
unded like you were confused about the terminology and what was happening t=
o your data (enough so that I still don=E2=80=99t know what=E2=80=99s not w=
orking for you with the Photoshop EXR plugin).<br>
<br>
Chris<br>
<br>
<br>
<br>
On 6/4/09 4:23 PM, "<a href=3D"[email protected]" target=3D"_blank">[email protected]=
</a>" &lt;<a href=3D"[email protected]" target=3D"_blank">[email protected]</a>&gt; w=
rote:<br>
<br>
</span></font><blockquote><font face=3D"Myriad Pro"><span style=3D"font-siz=
e: 10pt;">I'm working on a project that is rendering 32bit floating bit EXR=
 files out of 3DStudio. &nbsp;I'm then compiling these frames in After Effe=
cts in a 32 bit floating point composite and it's all working fine. &nbsp;T=
he problem I'm having is that I also need to composite some scenes in Photo=
shop CS4, and the default Photoshop EXR plugin is tossing out any data from=
 the image that has a transparent alpha. &nbsp;I found the Photoshop plugin=
 on the OpenEXR website and had hopes that it would do what I needed. &nbsp=
;Thankfully it knows how to handle the alpha channel properly, but unfortun=
ately the plugin imports the image into a 16bit integer document and any va=
lue above 1.0 is clipped. &nbsp;I can't use the exposure adjustment to acce=
ss the over bright details. &nbsp;Because of these import problems I have t=
o run each image through After Effects and do the exposure processing there=
, then export an image to Photoshop.<br>
<br>
Can the maintainer of the OpenEXR photoshop plugin please recompile a new v=
ersion that imports images into a 32bit document and maintain the full colo=
r range, or provide exposure controls in the plugin? &nbsp;Also, I could us=
e a 64bit version of the plugin for the 64bit version of Photoshop.<br>
<br>
Thanks,<br>
&nbsp;&nbsp;Ray Collett<br>
<br>
--<br>
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D<br>
--=3D=3D-- &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbs=
p;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Ray Collett &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&=
nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;--=3D=3D--<br>
Technical Director; Newlands &amp; Company Inc. www.nc3d.com<br>
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D<br>
<br>
<br>
_______________________________________________<br>
Openexr-user mailing list<br>
<a href=3D"[email protected]" target=3D"_blank">[email protected]=
rg</a><br>
<a href=3D"http://lists.nongnu.org/mailman/listinfo/openexr-user" target=3D=
"_blank">http://lists.nongnu.org/mailman/listinfo/openexr-user</a><br>
<br>
</span></font></blockquote>
<br></div></body></html>
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