# getCompression(_:factor:) Returns by indirection the bitmap image representation’s compression type and compression factor. ``` func getCompression(_ compression: UnsafeMutablePointer?, factor: UnsafeMutablePointer?) ``` ## Parameters `compression` On return, an `enum` constant that represents the compression type used on the data; it corresponds to one of the values returned by the class method [`getTIFFCompressionTypes(_:count:)`](/documentation/AppKit/NSBitmapImageRep/getTIFFCompressionTypes(_:count:)). `factor` A float value that is specific to the compression type. Many types of compression don’t support varying degrees of compression and thus ignore `factor`. JPEG compression allows a compression factor ranging from 0.0 to 1.0, with 0.0 being the lowest and 1.0 being the highest. ## Discussion Use this method to get information on the compression type for the source image 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)