# vImagePermuteChannels_ARGB16U(_:_:_:_:) Permutes the channels of an unsigned 16-bit-per-channel, 4-channel interleaved buffer. ``` func vImagePermuteChannels_ARGB16U(_ src: UnsafePointer, _ dest: UnsafePointer, _ permuteMap: UnsafePointer, _ flags: vImage_Flags) -> vImage_Error ``` ## Parameters `src` The source vImage buffer. `dest` A pointer to the destination vImage buffer structure. You’re responsible for filling out the [`height`](/documentation/Accelerate/vImage_Buffer/height), [`width`](/documentation/Accelerate/vImage_Buffer/width), and [`rowBytes`](/documentation/Accelerate/vImage_Buffer/rowBytes) fields of this structure, and for allocating a data buffer of the appropriate size. On return, the data buffer this structure points to contains the destination image data. When you no longer need the data buffer, deallocate the memory to prevent memory leaks. `permuteMap` An array of four 8-bit integers with the values `0`, `1`, `2`, and 3, in some order. Each value specifies the channel from the source image that the function copies to the destination channel at the corresponding index. `flags` The options to use when performing the operation. If your code implements its own tiling or its own multithreading, pass [`kvImageDoNotTile`](/documentation/Accelerate/kvImageDoNotTile); otherwise, pass [`kvImageNoFlags`](/documentation/Accelerate/kvImageNoFlags). ## Return Value [`kvImageNoError`](/documentation/Accelerate/kvImageNoError); otherwise, one of the error codes in . ## Discussion The following code reverses the channel ordering of a pixel buffer: ```swift let pixelBuffer = vImage.PixelBuffer( pixelValues: [10, 20, 30, 40], size: .init(width: 1, height: 1)) pixelBuffer.withUnsafePointerToVImageBuffer { buf in _ = vImagePermuteChannels_ARGB16U(buf, buf, [3, 2, 1, 0], vImage_Flags(kvImageNoFlags)) } // Prints "[40, 30, 20, 10]". print(pixelBuffer.array) ``` --- 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)