Enables detection of the OpenColorIO colorspace of an image file by looking at the filename itself. If set to 1, detection is enabled. The longest, rightmost string that matches a colorspace will be taken as the colorspace. If none are found, use Houdini’s heuristics for determining the colorspace (JPG is sRGB, EXR is linear, etc). If set to 2, detection occurs in the same way but when no colorspace is found, the “default” role defined by the OpenColorIO config.ocio file is used (OpenColorIO strict parsing). When set to 0, detection is not performed and Houdini’s native heuristics are used to determine the colorspace. When using OpenColorIO 2.0 and above, this uses the file_rules defined in the OpenColorIO config file.

When set to 3, color space detection will be done with a more strict detection algorithm. In this mode, color spaces embedded in filenames must be delimited by a period (.), underscore (_) , hyphen (-) or space. Using OpenColorIO parsing, “StrawHat.exr” would be interpreted as being in raw colorspace. With strict parsing, this is not the case.

When set to 4 (default), this uses the OpenColorIO file parsing, but when using file_rules, this will return an empty string rather than the “default” color space. This uses an efficient evaluator for the file_rules, but may not be 100% compatible with OCIO. Setting to 5will use the OCIO library file_rule parsing but have the same behavior as when set to 5.

This only has an effect if a valid OCIO environment variable is set.