Python API¶

Description¶

A color configuration (PyOpenColorIO.Config) defines all the color spaces to be available at runtime.

(PyOpenColorIO.Config) is the main object for interacting with this library. It encapsulates all the information necessary to use customized PyOpenColorIO.ColorSpaceTransform and PyOpenColorIO.DisplayTransform operations.

See the User Guide for more information on selecting, creating, and working with custom color configurations.

For applications interested in using only one color configuration at a time (this is the vast majority of apps), their API would traditionally get the global configuration and use that, as opposed to creating a new one. This simplifies the use case for plugins and bindings, as it alleviates the need to pass around configuration handles.

An example of an application where this would not be sufficient would be a multi-threaded image proxy server (daemon) that wants to handle multiple show configurations concurrently in a single process. This app would need to keep multiple configurations alive, and manage them appropriately.

Roughly speaking, a novice user should select a default configuration that most closely approximates the use case (animation, visual effects, etc.), and set the OCIO environment variable to point at the root of that configuration.

Note

Initialization using environment variables is typically preferable in a multi-app ecosystem, as it allows all applications to be consistently configured.

Note

Paths to LUTs can be relative. The search paths are defined in PyOpenColorIO.Config.

See Usage Examples

Examples of Use¶

import PyOpenColorIO as OCIO

# Load an existing configuration from the environment.
# The resulting configuration is read-only. If $OCIO is set, it will use that.
# Otherwise it will use an internal default.
config = OCIO.GetCurrentConfig()

# What color spaces exist?
colorSpaceNames = [ cs.getName() for cs in config.getColorSpaces() ]

# Given a string, can we parse a color space name from it?
inputString = 'myname_linear.exr'
colorSpaceName = config.parseColorSpaceFromString(inputString)
if colorSpaceName:
    print 'Found color space', colorSpaceName
else:
    print 'Could not get color space from string', inputString

# What is the name of scene-linear in the configuration?
colorSpace = config.getColorSpace(OCIO.Constants.ROLE_SCENE_LINEAR)
if colorSpace:
    print colorSpace.getName()
else:
    print 'The role of scene-linear is not defined in the configuration'

# For examples of how to actually perform the color transform math,
# see 'Python: Processor' docs.

# Create a new, empty, editable configuration
config = OCIO.Config()

# Create a new color space, and add it
cs = OCIO.ColorSpace(...)
# (See ColorSpace for details)
config.addColorSpace(cs)

# For additional examples of config manipulation, see
# https://github.com/imageworks/OpenColorIO-Configs/blob/master/nuke-default/make.py

Exceptions¶

class PyOpenColorIO.Exception¶: An exception class to throw for errors detected at runtime.

Warning

All functions in the Config class can potentially throw this exception.

class PyOpenColorIO.ExceptionMissingFile¶: An exception class for errors detected at runtime, thrown when OCIO cannot find a file that is expected to exist. This is provided as a custom type to distinguish cases where one wants to continue looking for missing files, but wants to properly fail for other error conditions.

Global¶

PyOpenColorIO.ClearAllCaches()¶

PyOpenColorIO.GetCurrentConfig()¶

PyOpenColorIO.GetLoggingLevel()¶

PyOpenColorIO.SetCurrentConfig()¶

PyOpenColorIO.SetLoggingLevel()¶

Config¶

class PyOpenColorIO.Config¶

Config

static CreateFromEnv()¶

Create a PyOpenColorIO.Config object using the environment variable.

Returns:	Config object

static CreateFromFile(filename)¶

Create a PyOpenColorIO.Config object using the information in a file.

Parameters:	filename (string) – name of file
Returns:	Config object

static CreateFromStream()¶

addColorSpace(pyColorSpace)¶

Add a specified color space to PyOpenColorIO.Config.

Parameters:	pyColorSpace (object) – color space

Note

If another color space is already registered with the same name, this will overwrite it.

addDisplay(display, view, colorSpaceName[, looks])¶

NEEDS WORK

Parameters:	display (string) – view (string) – colorSpaceName (string) – looks (string) – optional

addEnvironmentVar()¶

addLook(pylook)¶

Adds a look to PyOpenColorIO.Config.

Parameters:	pylook (look object) – look

clearColorSpaces()¶: Clear the color spaces in PyOpenColorIO.Config.

clearDisplays()¶

clearEnvironmentVars()¶

clearLook()¶

clearLooks()

Clear looks in PyOpenColorIO.Config.

clearLooks()¶: Clear looks in PyOpenColorIO.Config.

createEditableCopy()¶

Returns an editable copy of PyOpenColorIO.Config.

Returns:	editable copy of `PyOpenColorIO.Config`
Return type:	Config object

getActiveDisplays()¶

Returns the active displays in PyOpenColorIO.Config.

Returns:	active displays
Return type:	string

getActiveViews()¶

Returns the active views in PyOpenColorIO.Config.

Returns:	active views
Return type:	string

getCacheID([pycontext])¶

This will produce a hash of the all colorspace definitions, etc.

All external references, such as files used in FileTransforms, etc., will be incorporated into the cacheID. While the contents of the files are not read, the file system is queried for relavent information (mtime, inode) so that the PyOpenColorIO.Config‘s cacheID will change when the underlying luts are updated.

If a context is not provided, the current Context will be used. If a null context is provided, file references will not be taken into account (this is essentially a hash of PyOpenColorIO.Config.serialize()).

Parameters:	pycontext (object) – optional
Returns:	hash of `PyOpenColorIO.Config`
Return type:	string

getColorSpace(name)¶

Returns the data for the specified color space in PyOpenColorIO.Config.

This will return null if the specified name is not found.

Parameters:	name (string) – name of color space
Returns:	data for specified color space
Return type:	pyColorSpace object

getColorSpaceNameByIndex()¶

getColorSpaces()¶

Returns all the ColorSpaces defined in PyOpenColorIO.Config.

Returns:	ColorSpaces in `PyOpenColorIO.Config`
Return type:	tuple

getCurrentContext()¶

Return the current context, which is essentially a record of all the environment variables that are available for use in file path lookups.

Returns:	context
Return type:	pycontext

getDefaultDisplay()¶

Returns the default display set in PyOpenColorIO.Config.

Returns:	default display
Return type:	string

getDefaultLumaCoefs()¶

Returns the default luma coefficients in PyOpenColorIO.Config.

Returns:	luma coefficients
Return type:	list of floats

getDefaultView(display)¶

Returns the default view of PyOpenColorIO.Config.

Parameters:	display (string) – default view
Returns:	view
Return type:	string

getDescription()¶

Returns the stored description of PyOpenColorIO.Config.

Returns:	stored description of `PyOpenColorIO.Config`
Return type:	string

getDisplay()¶

getDisplayColorSpaceName(display, view)¶

Returns the ColorSpace name corresponding to the display and view combination in PyOpenColorIO.Config.

Parameters:	display (string) – display view (string) – view
Returns:	display color space name
Return type:	string

getDisplayLooks(display, view)¶

Returns the looks corresponding to the display and view combination in PyOpenColorIO.Config.

Parameters:	display (string) – display view (string) – view
Returns:	looks
Return type:	string

getDisplays()¶

Returns all the displays defined in PyOpenColorIO.Config.

Returns:	displays in `PyOpenColorIO.Config`
Return type:	list of strings

getEnvironmentVarDefault()¶

getEnvironmentVarDefaults()¶

getEnvironmentVarNameByIndex()¶

getIndexForColorSpace()¶

getLook(str)¶

Returns the information of a specified look in PyOpenColorIO.Config.

Parameters:	str (string) – look
Returns:	specified look
Return type:	look object

getLookNameByIndex()¶

getLooks()¶

Returns a list of all the looks defined in PyOpenColorIO.Config.

Returns:	looks
Return type:	tuple of look objects

getNumColorSpaces()¶

getNumDisplays()¶

getNumEnvironmentVars()¶

getNumLooks()¶

getNumRoles()¶

getNumViews()¶

getProcessor(arg1[, arg2[, direction[, context]])¶

Returns a processor for a specified transform.

Although this is not often needed, it allows for the reuse of atomic OCIO functionality, such as applying an individual LUT file.

There are two canonical ways of creating a PyOpenColorIO.Processor:

Pass a transform into arg1, in which case arg2 will be ignored.
Set arg1 as the source and arg2 as the destination. These can be ColorSpace names, objects, or roles.

Both arguments, direction (of transform) and context, are optional and respected for both methods of PyOpenColorIO.Processor creation.

This will fail if either the source or destination color space is null.

See Python: Processor for more details.

Note

This may provide higher fidelity than anticipated due to internal optimizations. For example, if inputColorSpace and outputColorSpace are members of the same family, no conversion will be applied, even though, strictly speaking, quantization should be added.

If you wish to test these calls for quantization characteristics, apply in two steps; the image must contain RGB triples (though arbitrary numbers of additional channels can be optionally supported using the pixelStrideBytes arg). ???

Parameters:	arg1 (object) – arg2 (object) – ignored if arg1 is a transform direction (string) – optional context (object) – optional

getRoleName()¶

getSearchPath()¶

Returns the search path.

Returns:	search path
Return type:	string

getView()¶

getViews(display)¶

Returns all the views defined in PyOpenColorIO.Config.

Parameters:	display (string) – views in `PyOpenColorIO.Config`
Returns:	views in `PyOpenColorIO.Config`.
Return type:	list of strings

getWorkingDir()¶

Returns the working directory.

Returns:	the working directory
Rtype path:	string

hasRole()¶

isEditable()¶

Returns whether Config is editable.

The configurations returned from PyOpenColorIO.GetCurrentConfig() are not editable, and if you want to edit them you can use PyOpenColorIO.Config.createEditableCopy().

If you attempt to call any of the set functions on a noneditable Config, an exception will be thrown.

Returns:	state of `PyOpenColorIO.Config`‘s editability
Return type:	bool

isStrictParsingEnabled()¶

parseColorSpaceFromString(str)¶

Parses out the color space from a string.

Given the specified string, gets the longest, right-most color space substring. * If strict parsing is enabled, and no color space is found, return an empty string. * If strict parsing is disabled, return the default role, if defined. * If the default role is not defined, return an empty string.

Parameters:	str (string) – ColorSpace data
Returns:	parsed data
Return type:	string

sanityCheck()¶: This will throw an exception if PyOpenColorIO.Config is malformed. The most common error occurs when references are made to colorspaces that do not exist.

serialize()¶

Returns the string representation of PyOpenColorIO.Config in YAML text form. This is typically stored on disk in a file with the .ocio extension.

Returns:	`PyOpenColorIO.Config` in YAML text form
Return type:	string

setActiveDisplays(displays)¶

Sets the active displays in PyOpenColorIO.Config.

Parameters:	displays (string) – active displays

setActiveViews(views)¶

Sets the active views in PyOpenColorIO.Config.

Parameters:	views (string) – active views

setDefaultLumaCoefs(pyCoef)¶

Sets the default luma coefficients in PyOpenColorIO.Config.

Parameters:	pyCoef (object) – luma coefficients

setDescription(desc)¶

Sets the description of PyOpenColorIO.Config.

Parameters:	desc (string) – description of `PyOpenColorIO.Config`

setRole(role, csname)¶

Set a role’s ColorSpace.

Setting the colorSpaceName name to a null string unsets it.

Parameters:	role (string) – role whose ColorSpace will be set csname (string) – name of ColorSpace

setSearchPath(path)¶

Sets the search path.

Parameters:	path (string) – the search path

setStrictParsingEnabled()¶

setWorkingDir(path)¶

Sets the working directory.

Parameters:	path (string) – the working directory

ColorSpace¶

class PyOpenColorIO.ColorSpace¶

A color space is the state of an image in terms of colorimetry and color encoding. I.e., it defines how an image’s color information needs to be interpreted.

Transforming images between different color spaces is the primary motivation for the OCIO library.

While a complete discussion of color spaces is beyond the scope of this documentation, traditional uses would be to have color spaces describing image capture devices, such as cameras and scanners, and internal ‘convenience’ spaces, such as scene-linear and logarithmic.

Color spaces are specific to a particular image precision (float32, uint8, etc.). The set of color spaces that provide equivalent mappings (at different precisions) are referred to as a ‘family’.

import PyOpenColorIO as OCIO
config = OCIO.Config()

createEditableCopy()¶

getAllocation()¶: If this colorspace needs to be transferred to a limited dynamic range coding space (such as during display with a GPU path), use this allocation to maximize bit efficiency.

getAllocationVars()¶

getBitDepth()¶

getDescription()¶

getEqualityGroup()¶

getFamily()¶

getName()¶

getTransform()¶

isData()¶

ColorSpaces that are data are treated a bit special. Basically, any colorspace transforms you try to apply to them are ignored. (Think of applying a gamut mapping transform to an ID pass). Also, the PyOpenColorIO.DisplayTransform process obeys special ‘data min’ and ‘data max’ args.

This is traditionally used for pixel data that represents non-color pixel data, such as normals, point positions, ID information, etc.

isEditable()¶

setAllocation()¶

setAllocationVars()¶

setBitDepth()¶

setDescription()¶

setEqualityGroup()¶

setFamily()¶

setIsData()¶

setName()¶

setTransform()¶

Look¶

class PyOpenColorIO.Look¶

The Look is an ‘artistic’ image modification, in a specified image state.

The processSpace defines the ColorSpace the image is required to be in, for the math to apply correctly.

createEditableCopy()¶

getDescription()¶

getInverseTransform()¶

getName()¶

getProcessSpace()¶

getTransform()¶

isEditable()¶

setDescription()¶

setInverseTransform()¶

setName()¶

setProcessSpace()¶

setTransform()¶

Processor¶

class PyOpenColorIO.Processor¶

Processor is the baked representation of a particular color transform. Once you have a process for a particular transform created, you can hang onto it to efficiently transform pixels.

Processors can only be created from the PyOpenColorIO.Config getProcessor(...) call.

applyRGB(pixeldata)¶

Apply the RGB part of the transform represented by PyOpenColorIO.Processor to an image.

Parameters:	pixeldata (object) – rgbrgb... array (length % 3 == 0)
Returns:	color converted pixeldata
Return type:	list

applyRGBA(pixeldata)¶

Apply the RGB and alpha part of the transform represented by PyOpenColorIO.Processor to an image.

Parameters:	pixeldata (object) – rgbargba... array (length % 4 == 0)
Returns:	color converted pixeldata
Return type:	list

getCpuCacheID()¶

Returns the cache ID of the CPU that PyOpenColorIO.Processor will run on.

Returns:	CPU cache ID
Return type:	string

getGpuLut3D(shaderDesc)¶

Returns the GPU LUT 3D.

Parameters:	shaderDesc (dict) – define ‘language’,’functionName’,’lut3DEdgeLen’
Returns:	GPU LUT 3D
Return type:	list

getGpuLut3DCacheID(shaderDesc)¶

Returns the GPU 3D LUT cache ID.

Parameters:	shaderDesc (dict) – two params
Returns:	GPU 3D LUT cache ID
Return type:	string

getGpuShaderText(shaderDesc)¶

Returns the GPU shader text.

Parameters:	shaderDesc (dict) – define ‘language’,’functionName’,’lut3DEdgeLen’
Returns:	GPU shader text
Return type:	string

getGpuShaderTextCacheID(shaderDesc)¶

Returns the GPU shader text cache ID.

Parameters:	shaderDesc (dict) – define ‘language’,’functionName’,’lut3DEdgeLen’
Returns:	GPU shader text cache ID
Return type:	string

getMetadata()¶

Returns information about the process that generated this processor.

Returns:	processor metadata
Return type:	PyOpenColorIO.ProcessorMetadata

hasChannelCrosstalk()¶

Returns whether the transformation of PyOpenColorIO.Processor introduces crosstalk between the image channels.

Returns:	whether there’s crosstalk between channels
Return type:	bool

isNoOp()¶

Returns whether the actual transformation represented by PyOpenColorIO.Processor is a no-op.

Returns:	whether transform is a no-op
Return type:	bool

Context¶

class PyOpenColorIO.Context¶

Context

clearStringVars()¶

createEditableCopy()¶

getCacheID()¶

getEnvironmentMode()¶

getNumStringVars()¶

getSearchPath()¶

getStringVar()¶

getStringVarNameByIndex()¶

getWorkingDir()¶

isEditable()¶

loadEnvironment()¶

resolveFileLocation()¶

resolveStringVar()¶

setEnvironmentMode()¶

setSearchPath()¶

setStringVar()¶

setWorkingDir()¶

OpenColorIO

Open Source Color Management

Quick search

Python API¶

Description¶

Examples of Use¶

Exceptions¶

Global¶

Config¶

ColorSpace¶

Look¶

Processor¶

Context¶