# CIFilterConstructor A general interface for objects that produce filters. ``` protocol CIFilterConstructor ``` ## Overview Objects implementing this protocol are called *filter constructors*—they produce new instances of [`CIFilter`](/documentation/CoreImage/CIFilter-swift.class) subclasses when filters are requested by name. You can create a filter constructor to provide new, custom filters that other Core Image clients can discover using the `CIFilter` class. Normally, you create and register custom filters by packaging them as Image Units (see [Packaging and Loading Image Units](https://developer.apple.com/library/archive/documentation/GraphicsImaging/Conceptual/CoreImaging/ci_image_units/ci_image_units.html#//apple_ref/doc/uid/TP30001185-CH7)), but you can use this protocol to provide new filters within your app that are compositions of existing filters. To provide custom filters using this protocol, you must: 1. Create your custom filters as `CIFilter` subclasses. 2. Create a class that implements this protocol to vend instances of the appropriate `CIFilter` subclasses when requested. 3. Call the `CIFilter` class method [`registerName(_:constructor:classAttributes:)`](/documentation/CoreImage/CIFilter-swift.class/registerName(_:constructor:classAttributes:)) for each custom filter, providing the filter’s name, an instance of your filter constructor class, and information about the filter’s attributes. ## Topics ### Providing Filter Objects [`- filterWithName:`](/documentation/CoreImage/CIFilterConstructor/filter(withName:)) Returns a filter object specified by name. ## Relationships ### Conforming Types [`CIFilterGenerator`](/documentation/CoreImage/CIFilterGenerator) --- 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)