---
title: Filter Attribute Keys
framework: coreimage
role: collectionGroup
role_heading: API Collection
path: coreimage/filter-attribute-keys
---

# Filter Attribute Keys

Attributes for a filter and its parameters.

## Overview

Overview Attribute keys are used for the attribute dictionary of a filter.  Most entries in the attribute dictionary are optional. The attribute kCIAttributeFilterName is mandatory. For a parameter, the attribute kCIAttributeClass is mandatory because it specifies the class name of the filter. A parameter of type NSNumber does not necessarily need the attributes kCIAttributeMin and kCIAttributeMax. These attributes are not present when the parameter has no upper or lower bounds. For example, the Gaussian blur filter has a radius parameter with a minimum of 0 but no maximum value to indicate that all nonnegative values are valid.

## Topics

### Constants

- [kCIAttributeFilterName](coreimage/kciattributefiltername.md)
- [kCIAttributeFilterDisplayName](coreimage/kciattributefilterdisplayname.md)
- [kCIAttributeDescription](coreimage/kciattributedescription.md)
- [kCIAttributeFilterAvailable_Mac](coreimage/kciattributefilteravailable_mac.md)
- [kCIAttributeFilterAvailable_iOS](coreimage/kciattributefilteravailable_ios.md)
- [kCIAttributeReferenceDocumentation](coreimage/kciattributereferencedocumentation.md)
- [kCIAttributeFilterCategories](coreimage/kciattributefiltercategories.md)
- [kCIAttributeClass](coreimage/kciattributeclass.md)
- [kCIAttributeType](coreimage/kciattributetype.md)
- [kCIAttributeMin](coreimage/kciattributemin.md)
- [kCIAttributeMax](coreimage/kciattributemax.md)
- [kCIAttributeSliderMin](coreimage/kciattributeslidermin.md)
- [kCIAttributeSliderMax](coreimage/kciattributeslidermax.md)
- [kCIAttributeDefault](coreimage/kciattributedefault.md)
- [kCIAttributeIdentity](coreimage/kciattributeidentity.md)
- [kCIAttributeName](coreimage/kciattributename.md)
- [kCIAttributeDisplayName](coreimage/kciattributedisplayname.md)

## See Also

### Constants

- [Data Type Attributes](coreimage/data-type-attributes.md)
- [Vector Quantity Attributes](coreimage/vector-quantity-attributes.md)
- [Color Attribute Keys](coreimage/color-attribute-keys.md)
- [Image Attribute Keys](coreimage/image-attribute-keys.md)
- [Filter Category Keys](coreimage/filter-category-keys.md)
- [Options for Applying a Filter](coreimage/options-for-applying-a-filter.md)
- [User Interface Control Options](coreimage/user-interface-control-options.md)
- [User Interface Options](coreimage/user-interface-options.md)
- [Filter Parameter Keys](coreimage/filter-parameter-keys.md)
- [RAW Image Options](coreimage/raw-image-options.md)