Re: Photoshop Plugin importing as RGB/16 bit

Chris Cox <[email protected]> Fri, 5 Jun 2009 15:00:55 -0700
Newsgroups gmane.comp.video.openexr.user
Message-ID <C64EE3A7.802A0%[email protected]>
--===============1571738679==
Content-Language: en
Content-Type: multipart/alternative;
	boundary="_000_C64EE3A7802A0ccoxadobecom_"

--_000_C64EE3A7802A0ccoxadobecom_
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable

Again, Photoshop is a straight color application - there is no such thing a=
s color values when the opacity is zero.

PNG is also well defined in it's behavior - and behaves exactly as the file=
 format specification says it must.
TIFF can support alpha channels (which can contain anything) AND transparen=
cy/opacity channels.  It sounds like you have these confused.

Chris




On 6/5/09 10:14 AM, "[email protected]" <[email protected]> wrote:

Hi Chris,
  Maybe I didn't explain this well enough.  There really is a couple of iss=
ues here.  So to explain further, I have an EXR file rendered out of 3DStud=
io in a HDR scene.  The scene is a landscape with buildings, hills, and a s=
ky.  The hills and buildings have an alpha of 1.0, the sky has an alpha of =
0.0.  The RGB information is not limited to a 0.0 - 1.0 range...  there are=
 some color values that go up into the 5.0-8.0 range (for example bright re=
flections on the windows, and the color of the clouds in the sky).

  If I use the default EXR plugin in CS4 it creates an RGB/32 document, but=
 the sky comes in 100% transparent.  This is great if I don't need the sky,=
 but there is color data for the sky in the EXR file.  The sky is blue and =
there 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 Ph=
otoshop there are no options to do this.  The EXR plugin is not the only on=
e that does this.  The PNG plugin for example also discards all color data =
where the alpha is 0.0.  The TIFF plugin on the other hand puts the alpha i=
nformation into a sepperate channel.  I can then choose to use that alpha h=
owever I wish.  Sometimes it's nice to have the alpha pre-composited with t=
he RGB data the way the PNG/EXR plugin works, but it would also be nice to =
have an option somewhere that modifies how Photoshop deals with alpha in an=
 image.  I would love an option in the main program settings that globally =
modified how all image importers dealt with the Alpha.

  Now if I use the plugin on the OpenEXR website, it brings up a dialog whe=
re I can choose to Un-Premultiply, I can change the Gamma, and I can alter =
the Exposure.  It also places the alpha into a sepperate channel like the w=
ay the TIFF plugin works.  I can see my sky and I have my alpha in a sepper=
ate channel so that I can do with it what I please.  The two problems I hav=
e with this plugin is that; 1) It creates an RGB/16 document instead of a R=
GB/32 which clamps the RGB values and leaves me stuck with the gamma/exposu=
re settings I selected during import, and 2) There is no 64bit version of t=
he plugin.

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

I hope this posting is more clear.

-Ray

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

Re: [Openexr-user] Photoshop Plugin importing as RGB/16 bit 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_C64EE3A7802A0ccoxadobecom_
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'>Again, Photoshop i=
s a straight color application &#8211; there is no such thing as color valu=
es when the opacity is zero.<BR>
<BR>
PNG is also well defined in it&#8217;s behavior &#8211; and behaves exactly=
 as the file format specification says it must.<BR>
TIFF can support alpha channels (which can contain anything) AND transparen=
cy/opacity channels. &nbsp;It sounds like you have these confused.<BR>
<BR>
Chris<BR>
<BR>
&nbsp;<BR>
<BR>
<BR>
On 6/5/09 10:14 AM, &quot;<a href=3D"[email protected]">[email protected]</a>&quot; &=
lt;<a href=3D"[email protected]">[email protected]</a>&gt; wrote:<BR>
<BR>
</SPAN></FONT><BLOCKQUOTE><FONT SIZE=3D"4"><FONT FACE=3D"Times New Roman"><=
SPAN STYLE=3D'font-size:12pt'>Hi Chris,<BR>
&nbsp;&nbsp;Maybe I didn't explain this well enough. &nbsp;There really is =
a couple of issues here. &nbsp;So to explain further, I have an EXR file re=
ndered out of 3DStudio in a HDR scene. &nbsp;The scene is a landscape 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 not 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 c=
olor of the clouds in the sky).<BR>
<BR>
&nbsp;&nbsp;If I use the default EXR plugin in CS4 it creates an RGB/32 doc=
ument, but the sky comes in 100% transparent. &nbsp;This is great if I don'=
t need the sky, but there is color data for the sky in the EXR file. &nbsp;=
The sky is blue and there are white clouds. &nbsp;In After Effects I can al=
ter the way it deals with the alpha, and I have the choice to ignore the al=
pha 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 ex=
ample also discards all color data where the alpha is 0.0. &nbsp;The TIFF p=
lugin 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 P=
NG/EXR plugin works, but it would also be nice to have an option somewhere =
that modifies how Photoshop deals with alpha in an image. &nbsp;I would lov=
e an option in the main program settings that globally modified how all ima=
ge importers dealt with the Alpha.<BR>
<BR>
&nbsp;&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, and I =
can alter the Exposure. &nbsp;It also places the alpha into a sepperate cha=
nnel 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. &nb=
sp;The two problems I have with this plugin is that; 1) It creates an RGB/1=
6 document instead of a RGB/32 which clamps the RGB values and leaves me st=
uck with the gamma/exposure settings I selected during import, and 2) There=
 is no 64bit version of the plugin.<BR>
<BR>
&nbsp;&nbsp;To recap, the default EXR plugin needs a user control for how i=
t deals with the alpha, and the OpenEXR plugin needs to open the image as a=
 RGB/32 so that it does not clamp the color values.<BR>
<BR>
I hope this posting is more clear.<BR>
<BR>
-Ray<BR>
<BR>
----- Original Message -----<BR>
From: &quot;Chris Cox&quot; &lt;<a href=3D"[email protected]">[email protected]</=
a>&gt;<BR>
To: <a href=3D"[email protected]">[email protected]</a>, <a href=3D"openexr-user@nong=
nu.org">[email protected]</a><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>
Re: [Openexr-user] Photoshop Plugin importing as RGB/16 bit </SPAN></FONT><=
/FONT><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><FONT SIZE=3D"4"><FONT FACE=3D"Times New Roman">=
<SPAN STYLE=3D'font-size:12pt'><BR>
</SPAN></FONT></FONT><FONT FACE=3D"Myriad Pro"><SPAN STYLE=3D'font-size:10p=
t'><BR>
</SPAN></FONT></BLOCKQUOTE>
</BODY>
</HTML>


--_000_C64EE3A7802A0ccoxadobecom_--



--===============1571738679==
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

--===============1571738679==--