ocioconvert: symbol lookup error: /usr/bin/../lib64/libOpenImageIO.so.2.2: undefined symbol: _ZN7Imf_3_16HeaderaSEOS0_

[tdbe]

I spent all day trying to get opencolorio to work. First I tried compiling it for windows which resulted in a roadblock dependency which is a tool that no longer exists on the internet, then I tried in wsl/ubuntu, then I finally installed a fedora virtualbox, installed opencolorio from yum and wanted to just do one simple ocioconvert CustomerImage.exr linear out.png srgb.

The result is this and I have absolutely no idea wtf ocioconvert: symbol lookup error: /usr/bin/../lib64/libOpenImageIO.so.2.2: undefined symbol: _ZN7Imf_3_16HeaderaSEOS0_

Does anyone have any idea wtf? Thanks. :)

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PS: there are absolutely no docs anywhere on the internet that explain the parameters that ocioconvert takes. Luckily I found the ocioconvert [input] [in colorspace] [output] [out color space] pattern while searching through the Issues on github :|

Looking at the docs here: https://opencolorio.readthedocs.io/en/latest/guides/using_ocio/using_ocio.html#overview-ocioconvert or here in the pdf: https://opencolorio.readthedocs.io/_/downloads/en/v2.0.0/pdf/ it is impossible to tell how the heck you actually run the ocioconvert command.

[carolalynn]

Hi @tdbe - first, apologies for all of the headache. Hopefully I can give a bit of context and background on the intent of the OCIO command line utilities, and also point you in the right direction.

First - the set of command line utilities that ship with OCIO were always meant just to be helper/tester tools to be used to verify functionality. ocioconvert is definitely not a tool I'd suggest for everyday image conversion in a production environment. For that, I would instead suggest oiiotool ( https://openimageio.readthedocs.io/en/latest/oiiotool.html) which is the command line utility for the image manipulation library OpenImageIO - it uses OCIO under the hood!

Second - your error. ocioconvert uses OpenImageIO to handle file format types/writing - so my first ask would be to make sure you have also installed OpenImageIO... though I bet you have, and actually your issue likely lies somewhere in....

A bit of a circular build dependency issue we've been battling for a bit now. OCIO depends on OIIO, but only for the command line utilities. However, OCIO is a required component to build core OIIO functionality. It's been a bit of a mess for awhile, more info in this issue: https://github.com/AcademySoftwareFoundation/OpenColorIO/issues/1233

Lastly, I very much hear you on the documentation issue. We are constantly working to make our documentation better, and we'll put this on the list. Quick question - does running ocioconvert -h yield any more information? It's been a long time since I used it last :)

[tdbe]

Ah thanks a lot for the explanation! Some context form me:

• I was actually only intending to use these command line utilities to understand / debug how ocio does color space transformations; as a comparison point. Not relying on it for production. I am actually trying to implement a certain linear to srgb color conversion according to an aces ocioconfig file, in an openGL shader. An artist obtained a 1d lut and a 3d lut that were supposed to do the job and match another software we use and want to emulate. But either we're not applying the luts right or ocio actually works differently from how we think it is.

Anyway, long story short, what I was really looking for was to apply an ocio profile in one of your tools, and then to somehow obtain / output the shader for that transformation, so I can see how it's done under the hood so I can replicate that transform in my glsl shader. ^__^ But I was probably not on the right track

I guess for now I will try oiio to at least see how the results are supposed to look; I also see I can actually find windows exes for it

PS: `[tdbe@fedora ~]$ ocioconvert -help

ocioconvert: symbol lookup error: /usr/bin/../lib64/libOpenImageIO.so.2.2: undefined symbol: _ZN7Imf_316HeaderaSEOS0

`

[remia]

Looks like there is some issue with OpenImageIO / OpenEXR from your load error, maybe ldd would give more clues.

The CI and Analysis workflows show some ways you can compile on Windows, though I agree sometimes it can be frustrating dealing with unexpected build issues and I also faced that.

To dump the shader code used by OCIO, you can use --gpu (or --gpulegacy if the software you want to emulate use OCIO v1) and --gpuinfo arguments for ocioconvert.

ocioconvert -- apply colorspace transform to an image

usage: ocioconvert [options]  inputimage inputcolorspace outputimage outputcolorspace
   or: ocioconvert [options] --lut lutfile inputimage outputimage
   or: ocioconvert [options] --view inputimage inputcolorspace outputimage displayname viewname

Options:
    --lut                  Convert using a LUT rather than a config file
    --view                 Convert to a (display,view) pair rather than to an output color space
    --gpu                  Use GPU color processing instead of CPU (CPU is the default)
    --gpulegacy            Use the legacy (i.e. baked) GPU color processing instead of the CPU one (--gpu is ignored)
    --gpuinfo              Output the OCIO shader program
    --help                 Print help message
    -v                     Display general information

OpenImageIO options:
    --float-attribute %L   "name=float" pair defining OIIO float attribute for outputimage
    --int-attribute %L     "name=int" pair defining OIIO int attribute for outputimage
    --string-attribute %L  "name=string" pair defining OIIO string attribute for outputimage
    --croptofull           Crop or pad to make pixel data region match the "full" region
    --ch %s                Select channels (e.g., "2,3,4")

It may be nice to add a simple way to check OCIO transforms, same as ociochecklut does but for arbitrary colorspace or display/view conversions. Maybe ociochecklut could be extended to support that.