# withUnsafeVImageBuffer(_:) Calls the given closure with the underlying vImage buffer. ``` func withUnsafeVImageBuffer(_ body: (vImage_Buffer) throws -> R) rethrows -> R ``` ## Parameters `body` A closure with a [`vImage_Buffer`](/documentation/Accelerate/vImage_Buffer) parameter that points to the underlying vImage buffer of the pixel buffer. ## Return Value The return value, if any, of the body closure parameter. ## Discussion Use this function to incorporate pixel buffer based image processing code with existing vImage code. For example, the following code accesses a pixel buffer’s underlying vImage buffer’s `rowBytes` property: ```swift let src = try vImage.PixelBuffer(cgImage: cgImage, cgImageFormat: &cgImageFormat) src.withUnsafeVImageBuffer { vImageBuffer in print(vImageBuffer.rowBytes) } ``` --- 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)