ocio2icc - Can I Create An ICC Profile From An Existing 3dl/csp LUT?

[Jordan Soles]

First off, major congrats and thanks for open-sourcing this as it's something I'm very interested in embedding in our studio.

That said, I was wondering if there was a way to create an ICC profile directly from 3DL or CSP lut? I think it's possible, but it appears to be somewhat constrained to the creation of a proper ocio config (which I'm still learning how to build).

Thanks,

Jordan

[Jeremy Selan]

> First off, major congrats and thanks for open-sourcing this as it's
> something I'm very interested in embedding in our studio.

Thanks!

> That said, I was wondering if there was a way to create an ICC profile
> directly from 3DL or CSP lut? I think it's possible, but it appears to be
> somewhat constrained to the creation of a proper ocio config (which I'm
> still learning how to build).

Currently, no.

Both ociobakelut and ocio2icc require an ocio profile. However, it
would be a pretty simple change to add the functionality to allow you
to specify a single lut (or luts) on the command-line instead.

I'll see if I can knock this feature off in the next few days.

-- Jeremy

[Gresham Lochner]

Hey all,

This exact issue has been on my to do list for a long time. Previously I
looked at spaceman icc (http://www.lightillusion.com/spaceman.htm) but
never had enough time to get it working properly. I'd love to see this
feature added to ocio. While we're on the issue, I'd love to get
people's opinion on their photoshop-nuke workflow. I believe I heard
Jeremy mention Sony brings their stuff in a neutral color space (in
photoshop) rather than trying to match what nuke see's with a cubic lut
applied. Is that true?
Ultimately I'm looking for a way to have a cubic lut that's being
applied in nuke, affect my matte paintings in photoshop and it look
identical.

Thanks,

- Gresham

[Jeremy Selan]

On Fri, Sep 9, 2011 at 3:20 PM, Gresham Lochner
<gresham...@gmail.com> wrote:
>  I believe I heard Jeremy mention Sony
> brings their stuff in a neutral color space (in photoshop) rather than
> trying to match what nuke see's with a cubic lut applied. Is that true?

Let me clarify. The colorspace we work in for texturing is partially
(but not totally) neutral.

Our rendering is in HDR linear, and the way our pixels get to the
scene is (approx):

(HDR scene-linear image) -> 1D Tonemapping to Display space (LDR
display pixels) -> 3D Filmic Color Warp (final film emulation preview)

In nuke/katana, as we're starting with hdr linear, both of these steps
(1d tone mapping + 3d color warp) happen in the viewer.

In photoshop, we paint directly in the LDR display pixel space, and we
apply only need to apply the 3D filmic component to preview the image
accurately.

It's nice to paint in this 'intermediate' colorspace because:
- the transformation back to scene-linear for rendering is only a 1d
transform (no inverse 3d luts)
- also, because the ldr painting space has a gamma very similar to the
monitor, things like color pickers / reference art work well.

For those who are not familiar with opencolorio.org, we've put
together a basic description of our color practices which is available
here. Of particular interest is the dt colorspace (diffuse-texture),
which corresponds to the intermediate space mentioned above.

http://opencolorio.org/workflow/spi_workflow.html
http://opencolorio.org/workflow/spi_vfx.html

-- Jeremy

[Jordan Soles]

Hi Jeremy,

Thanks very much for your response and it would be absolutely amazing if you could add that option into to specify a 3D lut path.

If that's a fairly substantial amount of work, is there a way to work-around it for now by just defining it in the ocio profile?

Thanks,

Jordan

[dbr/Ben]

With "mylut.csp", and the following saved as "example.yaml" (http://pastie.org/2523829 incase the formatting is screwed up):

ocio_profile_version: 1

# Look in current working dir for LUT

resource_path: "."

roles:

  scene_linear: ref

displays:

  blah:

    - !<View> {device: blahview, name: ref, colorspace: ref}

colorspaces:

  - !<ColorSpace>

    name: ref

    family: ref

    bitdepth: 32f

    isdata: false

  - !<ColorSpace>

     name: mylut

     family: mylut

     bitdepth: 32f

     isdata: false

     from_reference: !<FileTransform>{src: mylut.csp, interpolation: linear}

Then run:

ociobakelut --iconfig example.yaml --inputspace ref --outputspace mylut --format houdini out.lut

..or:

ocio2icc --iconfig example.yaml --inputspace ref --outputspace mylut out.icc

Not entirely straight forward, would be nice to specify a file as an argument to ociobakelut (or maybe a separate ocioconvertlut?)

[mich...@gmail.com]

Can you do one with it for me. I can pay

[Sean Cooper]

Assuming that you have OCIO compiled, the command line tool "ociobakelut" should fill that need.

ociobakelut --lut <your_lut.3dl> --format icc --description <description> <output_file.icc>

There is an additional optional parameter --whitepoint  which defaults to 6505KA

On Tue, Feb 21, 2017 at 9:48 AM, <mich...@gmail.com> wrote:

Can you do one with it for me. I can pay

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[mich...@gmail.com]

I don't have