# Color transforms Convert color from one profile’s color space to another. ## Overview A [`ColorSyncTransform`](/documentation/ColorSync/ColorSyncTransform) precomputes the conversion between a sequence of profiles. Color conversion requires significant computation, so the way you apply a transform affects performance. To convert pixels directly, call [`ColorSyncTransformConvert(_:_:_:_:_:_:_:_:_:_:_:_:)`](/documentation/ColorSync/ColorSyncTransformConvert(_:_:_:_:_:_:_:_:_:_:_:_:)). For production code or large buffers, get better performance by extracting a ColorSync *code fragment* with [`ColorSyncCreateCodeFragment(_:_:)`](/documentation/ColorSync/ColorSyncCreateCodeFragment(_:_:)) and running it through . Describe the layout of your pixel buffers with the pixel-format constants in [Pixel format and data layout](/documentation/ColorSync/pixel-format). ## Topics ### Representing transforms [`ColorSyncTransform`](/documentation/ColorSync/ColorSyncTransform) A reference to a color transform that converts color data between profiles. ### Creating and applying a transform [`ColorSyncTransformCreate`](/documentation/ColorSync/ColorSyncTransformCreate(_:_:)) Creates a color transform from a sequence of profiles. [`ColorSyncTransformConvert`](/documentation/ColorSync/ColorSyncTransformConvert(_:_:_:_:_:_:_:_:_:_:_:_:)) Converts color data from a source layout to a destination layout using a color transform. [`ColorSyncTransformGetProfileSequence`](/documentation/ColorSync/ColorSyncTransformGetProfileSequence(_:)) Returns the profile sequence used to create a color transform. [`ColorSyncTransformCopyProperty`](/documentation/ColorSync/ColorSyncTransformCopyProperty(_:_:_:)) Copies a property from a color transform. [`ColorSyncTransformSetProperty`](/documentation/ColorSync/ColorSyncTransformSetProperty(_:_:_:)) Sets a property on a color transform. [`ColorSyncTransformGetTypeID`](/documentation/ColorSync/ColorSyncTransformGetTypeID()) Returns the type identifier for the `ColorSyncTransform` opaque type. ### Choosing rendering intents [`kColorSyncRenderingIntent`](/documentation/ColorSync/kColorSyncRenderingIntent) A key for the rendering intent to use for the profile in a profile-sequence dictionary. [`kColorSyncRenderingIntentPerceptual`](/documentation/ColorSync/kColorSyncRenderingIntentPerceptual) A [`kColorSyncRenderingIntent`](/documentation/ColorSync/kColorSyncRenderingIntent) value selecting the perceptual rendering intent. [`kColorSyncRenderingIntentRelative`](/documentation/ColorSync/kColorSyncRenderingIntentRelative) A [`kColorSyncRenderingIntent`](/documentation/ColorSync/kColorSyncRenderingIntent) value selecting the media-relative colorimetric rendering intent. [`kColorSyncRenderingIntentSaturation`](/documentation/ColorSync/kColorSyncRenderingIntentSaturation) A [`kColorSyncRenderingIntent`](/documentation/ColorSync/kColorSyncRenderingIntent) value selecting the saturation rendering intent. [`kColorSyncRenderingIntentAbsolute`](/documentation/ColorSync/kColorSyncRenderingIntentAbsolute) A [`kColorSyncRenderingIntent`](/documentation/ColorSync/kColorSyncRenderingIntent) value selecting the ICC-absolute colorimetric rendering intent. [`kColorSyncRenderingIntentUseProfileHeader`](/documentation/ColorSync/kColorSyncRenderingIntentUseProfileHeader) A [`kColorSyncRenderingIntent`](/documentation/ColorSync/kColorSyncRenderingIntent) value selecting the rendering intent stored in the profile header. ### Proofing and gamut checking [`ColorSyncProfileCreateLink`](/documentation/ColorSync/ColorSyncProfileCreateLink(_:_:)) Creates a device link profile from an array of profiles. [`kColorSyncTransformDeviceToDevice`](/documentation/ColorSync/kColorSyncTransformDeviceToDevice) A [`kColorSyncTransformTag`](/documentation/ColorSync/kColorSyncTransformTag) value selecting the device-to-device conversion direction. [`kColorSyncTransformGamutCheck`](/documentation/ColorSync/kColorSyncTransformGamutCheck) A [`kColorSyncTransformTag`](/documentation/ColorSync/kColorSyncTransformTag) value that checks whether colors fall outside the destination gamut. ### Accessing transform properties [`kColorSyncProfile`](/documentation/ColorSync/kColorSyncProfile) A key for the profile object in a profile-sequence dictionary passed to [`ColorSyncTransformCreate(_:_:)`](/documentation/ColorSync/ColorSyncTransformCreate(_:_:)). [`kColorSyncTransformCreator`](/documentation/ColorSync/kColorSyncTransformCreator) A key for the name of the CMM that created the transform. [`kColorSyncTransformDeviceToPCS`](/documentation/ColorSync/kColorSyncTransformDeviceToPCS) A [`kColorSyncTransformTag`](/documentation/ColorSync/kColorSyncTransformTag) value selecting the device-to-PCS conversion direction. [`kColorSyncTransformDstSpace`](/documentation/ColorSync/kColorSyncTransformDstSpace) A key for the transform’s destination color space. [`kColorSyncTransformInfo`](/documentation/ColorSync/kColorSyncTransformInfo) A key for a dictionary of information about the transform. [`kColorSyncTransformPCSToDevice`](/documentation/ColorSync/kColorSyncTransformPCSToDevice) A [`kColorSyncTransformTag`](/documentation/ColorSync/kColorSyncTransformTag) value selecting the PCS-to-device conversion direction. [`kColorSyncTransformPCSToPCS`](/documentation/ColorSync/kColorSyncTransformPCSToPCS) A [`kColorSyncTransformTag`](/documentation/ColorSync/kColorSyncTransformTag) value selecting the PCS-to-PCS conversion direction. [`kColorSyncTransformProfileSequnce`](/documentation/ColorSync/kColorSyncTransformProfileSequnce) A key for the profile sequence used to create the transform. [`kColorSyncTransformSrcSpace`](/documentation/ColorSync/kColorSyncTransformSrcSpace) A key for the transform’s source color space. [`kColorSyncTransformTag`](/documentation/ColorSync/kColorSyncTransformTag) A key for the tag identifying which tags of the profile to use in a profile-sequence dictionary. ### Extracting a conversion for vImage [`ColorSyncCreateCodeFragment`](/documentation/ColorSync/ColorSyncCreateCodeFragment(_:_:)) Creates a code fragment from a sequence of profiles. [`kColorSyncTransformCodeFragmentType`](/documentation/ColorSync/kColorSyncTransformCodeFragmentType) A key for the type of code fragment to create, or that the framework created. [`kColorSyncTransformCodeFragmentMD5`](/documentation/ColorSync/kColorSyncTransformCodeFragmentMD5) A key for the MD5 checksum of the code fragment. ### Reading conversion data sets [`kColorSyncTransformFullConversionData`](/documentation/ColorSync/kColorSyncTransformFullConversionData) A key for the full-conversion code fragment, containing all non-`NULL` components from the profile sequence. [`kColorSyncTransformParametricConversionData`](/documentation/ColorSync/kColorSyncTransformParametricConversionData) A key for the parametric code fragment, consisting only of parametric curves, matrices, and BPC components. [`kColorSyncTransformSimplifiedConversionData`](/documentation/ColorSync/kColorSyncTransformSimplifiedConversionData) A key for the simplified code fragment, collapsing the full conversion into one multi-dimensional table. [`kColorSyncConversionBPC`](/documentation/ColorSync/kColorSyncConversionBPC) A key for a black point compensation component, represented as a `CFArray` of `Float32` `CFNumber`s. [`kColorSyncFixedPointRange`](/documentation/ColorSync/kColorSyncFixedPointRange) A key for the fixed-point range of the conversion data. ### Reading curves and matrices [`kColorSyncConversionParamCurve0`](/documentation/ColorSync/kColorSyncConversionParamCurve0) A key for a parametric tone rendering curve of type 0, represented as a `CFArray` of seven `Float32` `CFNumber`s. [`kColorSyncConversionParamCurve1`](/documentation/ColorSync/kColorSyncConversionParamCurve1) A key for a parametric tone rendering curve of type 1, represented as a `CFArray` of seven `Float32` `CFNumber`s. [`kColorSyncConversionParamCurve2`](/documentation/ColorSync/kColorSyncConversionParamCurve2) A key for a parametric tone rendering curve of type 2, represented as a `CFArray` of seven `Float32` `CFNumber`s. [`kColorSyncConversionParamCurve3`](/documentation/ColorSync/kColorSyncConversionParamCurve3) A key for a parametric tone rendering curve of type 3, represented as a `CFArray` of seven `Float32` `CFNumber`s. [`kColorSyncConversionParamCurve4`](/documentation/ColorSync/kColorSyncConversionParamCurve4) A key for a parametric tone rendering curve of type 4, represented as a `CFArray` of seven `Float32` `CFNumber`s. [`kColorSyncConversionMatrix`](/documentation/ColorSync/kColorSyncConversionMatrix) A key for a conversion matrix component, represented as a `CFArray` of three `CFArray`s of four `Float32` `CFNumber`s. ### Reading lookup tables [`kColorSyncConversion1DLut`](/documentation/ColorSync/kColorSyncConversion1DLut) A key for a one-dimensional lookup table with interpolation, represented as `CFData` containing a `Float32` table. [`kColorSyncConversion3DLut`](/documentation/ColorSync/kColorSyncConversion3DLut) A key for a three-dimensional lookup table with interpolation, represented as `CFData`. [`kColorSyncConversionNDLut`](/documentation/ColorSync/kColorSyncConversionNDLut) A key for a multi-dimensional lookup table with interpolation, represented as `CFData` for N inputs and M outputs. [`kColorSyncConversionGridPoints`](/documentation/ColorSync/kColorSyncConversionGridPoints) A key for the number of grid points in a lookup table. [`kColorSyncConversionChannelID`](/documentation/ColorSync/kColorSyncConversionChannelID) A key for the identifier of the channel a conversion component applies to. [`kColorSyncConversionInpChan`](/documentation/ColorSync/kColorSyncConversionInpChan) A key for the number of input channels of a lookup table. [`kColorSyncConversionOutChan`](/documentation/ColorSync/kColorSyncConversionOutChan) A key for the number of output channels of a lookup table. ### Setting conversion quality [`kColorSyncBestQuality`](/documentation/ColorSync/kColorSyncBestQuality) A [`kColorSyncConvertQuality`](/documentation/ColorSync/kColorSyncConvertQuality) value that does not coalesce profile transforms; the default. [`kColorSyncBlackPointCompensation`](/documentation/ColorSync/kColorSyncBlackPointCompensation) A key whose `CFBooleanRef` value enables or disables black point compensation. [`kColorSyncConvertQuality`](/documentation/ColorSync/kColorSyncConvertQuality) A key for the quality of the conversion performed by the transform. [`kColorSyncDraftQuality`](/documentation/ColorSync/kColorSyncDraftQuality) A [`kColorSyncConvertQuality`](/documentation/ColorSync/kColorSyncConvertQuality) value that coalesces all transforms and does not interpolate. [`kColorSyncNormalQuality`](/documentation/ColorSync/kColorSyncNormalQuality) A [`kColorSyncConvertQuality`](/documentation/ColorSync/kColorSyncConvertQuality) value that coalesces all transforms. ### Handling HDR and extended range [`kColorSyncExtendedRange`](/documentation/ColorSync/kColorSyncExtendedRange) A key whose `CFBooleanRef` value enables or disables extended range. [`kColorSyncConvertUseExtendedRange`](/documentation/ColorSync/kColorSyncConvertUseExtendedRange) A key whose `CFBooleanRef` value allows float data to exceed the `[0.0, 1.0]` range. [`kColorSyncTransformUseITU709OETF`](/documentation/ColorSync/kColorSyncTransformUseITU709OETF) A key whose `CFBooleanRef` value uses the ITU-R BT.709 opto-electronic transfer function. [`kColorSyncHDRDerivative`](/documentation/ColorSync/kColorSyncHDRDerivative) A key for the HDR derivative to apply to the profile in a profile-sequence dictionary. [`kColorSyncPQDerivative`](/documentation/ColorSync/kColorSyncPQDerivative) A [`kColorSyncHDRDerivative`](/documentation/ColorSync/kColorSyncHDRDerivative) value selecting the PQ HDR derivative. [`kColorSyncHLGDerivative`](/documentation/ColorSync/kColorSyncHLGDerivative) A [`kColorSyncHDRDerivative`](/documentation/ColorSync/kColorSyncHDRDerivative) value selecting the HLG HDR derivative. ### Choosing a color management module [`kColorSyncPreferredCMM`](/documentation/ColorSync/kColorSyncPreferredCMM) A key whose value is the [`ColorSyncCMM`](/documentation/ColorSync/ColorSyncCMM) of the preferred CMM. ### Iterating asynchronously [`COLORSYNC_ITERATE_ASYNC`](/documentation/ColorSync/COLORSYNC_ITERATE_ASYNC) --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)