Re: Photoshop Plugin importing as RGB/16 bit

Chris Cox <[email protected]> Thu, 4 Jun 2009 18:37:24 -0700
Newsgroups gmane.comp.video.openexr.user
Message-ID <C64DC4E4.80221%[email protected]>
--===============1858384078==
Content-Language: en
Content-Type: multipart/alternative;
	boundary="_000_C64DC4E480221ccoxadobecom_"

--_000_C64DC4E480221ccoxadobecom_
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable

Ray;

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 app=
lication, there is no meaning to color values when the opacity is zero.  If=
 the opacity is non-zero, then the color values are there -  just un-multip=
lied so they will composite correctly.

Photoshop already handles the EXR "A" channel (defined in the spec as opaci=
ty/transparency data) correctly - it opens it as opacity/transparency.
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.

I'm sorry I don't have a solution for you, but your post sounded like you w=
ere confused about the terminology and what was happening to your data (eno=
ugh so that I still don't know what's not working for you with the Photosho=
p EXR plugin).

Chris



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

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 havin=
g is that I also need to composite some scenes in Photoshop CS4, and the de=
fault 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 a=
nd had hopes that it would do what I needed.  Thankfully it knows how to ha=
ndle the alpha channel properly, but unfortunately the plugin imports the i=
mage into a 16bit integer document and any value above 1.0 is clipped.  I c=
an't use the exposure adjustment to access the over bright details.  Becaus=
e of these import problems I have to run each image through After Effects a=
nd do the exposure processing there, then export an image to Photoshop.

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 6=
4bit version of the plugin for the 64bit version of Photoshop.

Thanks,
  Ray Collett

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


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


--_000_C64DC4E480221ccoxadobecom_
Content-Type: text/html; charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable

<HTML>
<HEAD>
<TITLE>Re: [Openexr-user] Photoshop Plugin importing as RGB/16 bit</TITLE>
</HEAD>
<BODY>
<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 &#8220;A&#8221; channel (defined in the s=
pec as opacity/transparency data) correctly &#8211; it opens it as opacity/=
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&#8217;m sorry I don&#8217;t have a solution for you, but your post sounde=
d like you were confused about the terminology and what was happening to yo=
ur data (enough so that I still don&#8217;t know what&#8217;s not working f=
or you with the Photoshop EXR plugin).<BR>
<BR>
Chris<BR>
<BR>
<BR>
<BR>
On 6/4/09 4:23 PM, &quot;<a href=3D"[email protected]">[email protected]</a>&quot; &l=
t;<a href=3D"[email protected]">[email protected]</a>&gt; wrote:<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 f=
iles out of 3DStudio. &nbsp;I'm then compiling these frames in After Effect=
s in a 32 bit floating point composite and it's all working fine. &nbsp;The=
 problem I'm having is that I also need to composite some scenes in Photosh=
op CS4, and the default Photoshop EXR plugin is tossing out any data from t=
he image that has a transparent alpha. &nbsp;I found the Photoshop plugin o=
n the OpenEXR website and had hopes that it would do what I needed. &nbsp;T=
hankfully it knows how to handle the alpha channel properly, but unfortunat=
ely the plugin imports the image into a 16bit integer document and any valu=
e above 1.0 is clipped. &nbsp;I can't use the exposure adjustment to access=
 the over bright details. &nbsp;Because of these import problems I have to =
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]">[email protected]</a><BR>
<a href=3D"http://lists.nongnu.org/mailman/listinfo/openexr-user">http://li=
sts.nongnu.org/mailman/listinfo/openexr-user</a><BR>
<BR>
</SPAN></FONT></BLOCKQUOTE>
</BODY>
</HTML>


--_000_C64DC4E480221ccoxadobecom_--



--===============1858384078==
Content-Type: text/plain; charset="us-ascii"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

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

--===============1858384078==--