# withUnsafeBytes(as:_:) Encode a representation of this image in a given image format. ``` borrowing func withUnsafeBytes(as imageFormat: AttachableImageFormat, _ body: (UnsafeRawBufferPointer) throws -> R) throws -> R ``` ## Parameters `imageFormat` The image format to use when encoding this image. `body` A function to call. A temporary buffer containing a data representation of this instance is passed to it. ## Return Value Whatever is returned by `body`. ## Discussion> Throws: Whatever is thrown by `body`, or any error that prevented the > creation of the buffer. The testing library uses this function when saving an image as an attachment. The implementation should use `imageFormat` to determine what encoder to use. --- 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)