# init(data:width:height:byteCountPerRow:pixelFormat:) Returns a new buffer that references existing data. ``` init(data: UnsafeMutableRawPointer, width: Int, height: Int, byteCountPerRow: Int, pixelFormat: Format.Type) ``` ## Parameters `data` A pointer to the top-left pixel of the buffer. `width` The width, in pixels, of the pixel buffer. `height` The height, in pixels, of the pixel buffer. `byteCountPerRow` The number of bytes in a pixel row. `pixelFormat` The pixel format of the initialized buffer. ## Discussion You can use this function to simplify interoperation with other libraries and frameworks. For example, the following code shows a function that permutes the channels of a instance. The function creates a pixel buffer that uses the storage a instance’s property provides. The property is a copy of the image data, therefore, the code returns a new instance that it generates from the permuted pixel buffer. ```swift static func permute(image: CGImage, to permuteMap: (UInt8, UInt8, UInt8, UInt8)) -> CGImage? { let bitsPerPixel = image.bitsPerPixel let bitsPerComponent = image.bitsPerComponent guard bitsPerPixel == 32 && bitsPerComponent == 8, let format = vImage_CGImageFormat(cgImage: image), let pixelData = image.dataProvider?.data else { return nil } return withExtendedLifetime(pixelData) { let pixelBuffer = vImage.PixelBuffer( data: UnsafeMutableRawPointer(mutating: CFDataGetBytePtr($0)), width: image.width, height: image.height, byteCountPerRow: image.bytesPerRow, pixelFormat: vImage.Interleaved8x4.self) pixelBuffer.permuteChannels(to: permuteMap, destination: pixelBuffer) return pixelBuffer.makeCGImage(cgImageFormat: format) } } ``` > Important: > The pixel buffer is valid only for the lifetime of `data`. --- 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)