# Applying channel operations Extract, flatten, permute, and overwrite the individual color channels of a pixel buffer. ## Topics ### Extracting Channels [`func extractChannel(at: Int, destination: vImage.PixelBuffer)`](/documentation/Accelerate/vImage/PixelBuffer/extractChannel(at:destination:)-ageg) Extracts a single channel from an 8-bit-per-channel, 4-channel interleaved pixel buffer. [`func extractChannel(at: Int, destination: vImage.PixelBuffer)`](/documentation/Accelerate/vImage/PixelBuffer/extractChannel(at:destination:)-i1zm) Extracts a single channel from an unsigned 16-bit-per-channel, 4-channel interleaved pixel buffer. [`func extractChannel(at: Int, destination: vImage.PixelBuffer)`](/documentation/Accelerate/vImage/PixelBuffer/extractChannel(at:destination:)-8xrq1) Extracts a single channel from an 32-bit-per-channel, 4-channel interleaved pixel buffer. ### Flattening Channels [`func flatten(channelOrdering: vImage.ChannelOrdering, backgroundColor: Pixel_8888, isPremultiplied: Bool, destination: vImage.PixelBuffer)`](/documentation/Accelerate/vImage/PixelBuffer/flatten(channelOrdering:backgroundColor:isPremultiplied:destination:)-97nx) Transforms an 8-bit-per-channel RGBA or ARGB buffer to an RGB buffer against an opaque background color. [`func flatten(channelOrdering: vImage.ChannelOrdering, backgroundColor: Pixel_FFFF, isPremultiplied: Bool, destination: vImage.PixelBuffer)`](/documentation/Accelerate/vImage/PixelBuffer/flatten(channelOrdering:backgroundColor:isPremultiplied:destination:)-5g0c2) Transforms an 32-bit-per-channel RGBA or ARGB buffer to an RGB buffer against an opaque background color. [`enum ChannelOrdering`](/documentation/Accelerate/vImage/ChannelOrdering) Constants that specify the channel ordering of a pixel buffer. ### Permuting Channels [`func permuteChannels(to: (UInt8, UInt8, UInt8), destination: vImage.PixelBuffer)`](/documentation/Accelerate/vImage/PixelBuffer/permuteChannels(to:destination:)-4y4rh) Permutes the channels of an 8-bit-per-channel, 3-channel interleaved pixel buffer. [`func permuteChannels(to: (UInt8, UInt8, UInt8, UInt8), destination: vImage.PixelBuffer)`](/documentation/Accelerate/vImage/PixelBuffer/permuteChannels(to:destination:)-tr2h) Permutes the channels of an 8-bit-per-channel, 4-channel interleaved pixel buffer. [`func permuteChannels(to: (UInt8, UInt8, UInt8, UInt8), destination: vImage.PixelBuffer)`](/documentation/Accelerate/vImage/PixelBuffer/permuteChannels(to:destination:)-8y213) Permutes the channels of an unsigned 16-bit-per-channel, 4-channel interleaved pixel buffer. [`func permuteChannels(to: (UInt8, UInt8, UInt8, UInt8), destination: vImage.PixelBuffer)`](/documentation/Accelerate/vImage/PixelBuffer/permuteChannels(to:destination:)-74dmh) Permutes the channels of a floating-point 16-bit-per-channel, 4-channel interleaved pixel buffer. [`func permuteChannels(to: (UInt8, UInt8, UInt8, UInt8), destination: vImage.PixelBuffer)`](/documentation/Accelerate/vImage/PixelBuffer/permuteChannels(to:destination:)-6n6yi) Permutes the channels of an 32-bit-per-channel, 4-channel interleaved pixel buffer. ### Overwriting Channels [`func overwriteChannels(withScalar: Pixel_8)`](/documentation/Accelerate/vImage/PixelBuffer/overwriteChannels(withScalar:)-3zb93) Overwrites the pixels of the pixel buffer with the provided 8-bit scalar value. [`func overwriteChannels(withScalar: Pixel_16F)`](/documentation/Accelerate/vImage/PixelBuffer/overwriteChannels(withScalar:)-1hrrg) Overwrites the pixels of the pixel buffer with the provided floating-point 16-bit scalar value. [`func overwriteChannels(withScalar: Pixel_F)`](/documentation/Accelerate/vImage/PixelBuffer/overwriteChannels(withScalar:)-1wm1o) Overwrites the pixels of the pixel buffer with the provided 32-bit scalar value. [`func overwriteChannels([UInt8], withScalar: Pixel_8, destination: vImage.PixelBuffer)`](/documentation/Accelerate/vImage/PixelBuffer/overwriteChannels(_:withScalar:destination:)-57ov2) Overwrites the pixels of one or more channels of the pixel buffer with the provided 8-bit scalar value. [`func overwriteChannels([UInt8], withScalar: Pixel_F, destination: vImage.PixelBuffer)`](/documentation/Accelerate/vImage/PixelBuffer/overwriteChannels(_:withScalar:destination:)-ev8q) Overwrites the pixels of one or more channels of the pixel buffer with the provided 32-bit scalar value. [`func overwriteChannels([UInt8], withPixel: Pixel_8888, destination: vImage.PixelBuffer)`](/documentation/Accelerate/vImage/PixelBuffer/overwriteChannels(_:withPixel:destination:)-6fab6) Overwrites the pixels of one or more channels of the pixel buffer with the provided 8-bit, 4-channel pixel value. [`func overwriteChannels([UInt8], withPixel: Pixel_ARGB_16U, destination: vImage.PixelBuffer)`](/documentation/Accelerate/vImage/PixelBuffer/overwriteChannels(_:withPixel:destination:)-6zw3o) Overwrites the pixels of one or more channels of the pixel buffer with the provided unsigned 16-bit, 4-channel pixel value. [`func overwriteChannels([UInt8], withPixel: Pixel_FFFF, destination: vImage.PixelBuffer)`](/documentation/Accelerate/vImage/PixelBuffer/overwriteChannels(_:withPixel:destination:)-6pbz8) Overwrites the pixels of one or more channels of the pixel buffer with the provided 32-bit, 4-channel pixel value. [`func overwriteChannels([UInt8], withPlanarBuffer: vImage.PixelBuffer, destination: vImage.PixelBuffer)`](/documentation/Accelerate/vImage/PixelBuffer/overwriteChannels(_:withPlanarBuffer:destination:)-9jbky) Overwrites the pixels of one or more channels of the pixel buffer with the provided 8-bit planar pixel buffer. [`func overwriteChannels([UInt8], withPlanarBuffer: vImage.PixelBuffer, destination: vImage.PixelBuffer)`](/documentation/Accelerate/vImage/PixelBuffer/overwriteChannels(_:withPlanarBuffer:destination:)-hiw0) Overwrites the pixels of one or more channels of the pixel buffer with the provided 32-bit planar pixel buffer. [`func overwriteChannels([UInt8], withInterleavedBuffer: vImage.PixelBuffer, destination: vImage.PixelBuffer)`](/documentation/Accelerate/vImage/PixelBuffer/overwriteChannels(_:withInterleavedBuffer:destination:)-74hah) Overwrites the pixels of one or more channels of the pixel buffer with the provided 8-bit interleaved pixel buffer. [`func overwriteChannels([UInt8], withInterleavedBuffer: vImage.PixelBuffer, destination: vImage.PixelBuffer)`](/documentation/Accelerate/vImage/PixelBuffer/overwriteChannels(_:withInterleavedBuffer:destination:)-8xkd1) Overwrites the pixels of one or more channels of the pixel buffer with the provided 32-bit interleaved pixel buffer. --- 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)