iOS Developer Library

Developer

CoreImage Framework Reference CIImage Class Reference

Options
Deployment Target:

On This Page
Language:

CIImage

The CIImage class represents an image. Core Image images are immutable. You use CIImage objects in conjunction with other Core Image classes—such as CIFilter, CIContext, CIVector, and CIColor—to take advantage of the built-in Core Image filters when processing images. You can create CIImage objects with data supplied from a variety of sources, including Quartz 2D images, Core Video image buffers (CVImageBufferRef), URL-based objects, and NSData objects.

Although a CIImage object has image data associated with it, it is not an image. You can think of a CIImage object as an image “recipe.” A CIImage object has all the information necessary to produce an image, but Core Image doesn’t actually render an image until it is told to do so. This “lazy evaluation” method allows Core Image to operate as efficiently as possible.

CIContext and CIImage objects are immutable, which means each can be shared safely among threads. Multiple threads can use the same GPU or CPU CIContext object to render CIImage objects. However, this is not the case for CIFilter objects, which are mutable. A CIFilter object cannot be shared safely among threads. If you app is multithreaded, each thread must create its own CIFilter objects. Otherwise, your app could behave unexpectedly.

Core Image also provides autoadjustment methods that analyze an image for common deficiencies and return a set of filters to correct those deficiencies. The filters are preset with values for improving image quality by altering values for skin tones, saturation, contrast, and shadows and for removing red-eye or other artifacts caused by flash. (See “Getting Autoadjustment Filters”.)

For a discussion of all the methods you can use to create CIImage objects on iOS and OS X, see Core Image Programming Guide.

Inheritance


Conforms To


Import Statement


Swift

import CoreImage

Objective-C

@import CoreImage;

Availability


Available in iOS 5.0 and later.
  • Creates and returns an empty image object.

    Declaration

    Swift

    class func emptyImage() -> CIImage!

    Objective-C

    + (CIImage *)emptyImage

    Return Value

    An image object.

    Import Statement

    Objective-C

    @import CoreImage;

    Swift

    import CoreImage

    Availability

    Available in iOS 5.0 and later.

  • Creates and returns an image of infinite extent that is initialized the specified color.

    Declaration

    Objective-C

    + (CIImage *)imageWithColor:(CIColor *)color

    Parameters

    color

    A color object.

    Return Value

    The image object initialized with the color represented by the CIColor object.

    Import Statement

    Objective-C

    @import CoreImage;

    Availability

    Available in iOS 5.0 and later.

  • Creates and returns an image object from bitmap data.

    Declaration

    Objective-C

    + (CIImage *)imageWithBitmapData:(NSData *)d bytesPerRow:(size_t)bpr size:(CGSize)size format:(CIFormat)f colorSpace:(CGColorSpaceRef)cs

    Parameters

    d

    The bitmap data for the image. This data must be premultiplied.

    bpr

    The number of bytes per row.

    size

    The dimensions of the image.

    f

    The format and size of each pixel. You must supply a pixel format constant. See “Pixel Formats”.

    cs

    The color space that the image is defined in. If this value is nil, the image is not color matched. Pass nil for images that don’t contain color data (such as elevation maps, normal vector maps, and sampled function tables).

    Return Value

    An image object.

    Import Statement

    Objective-C

    @import CoreImage;

    Availability

    Available in iOS 5.0 and later.

  • Creates and returns an image object from a Quartz 2D image.

    Declaration

    Objective-C

    + (CIImage *)imageWithCGImage:(CGImageRef)image

    Parameters

    image

    A Quartz 2D image (CGImageRef) object. For more information, see Quartz 2D Programming Guide and CGImage Reference.

    Return Value

    An image object initialized with the contents of the Quartz 2D image.

    Import Statement

    Objective-C

    @import CoreImage;

    Availability

    Available in iOS 5.0 and later.

  • Creates and returns an image object from a Quartz 2D image using the specified options.

    Declaration

    Objective-C

    + (CIImage *)imageWithCGImage:(CGImageRef)image options:(NSDictionary *)d

    Parameters

    image

    A Quartz 2D image (CGImageRef) object. For more information, see Quartz 2D Programming Guide and CGImage Reference.

    d

    A dictionary specifying image options. (See “Image Dictionary Keys”.)

    Return Value

    An image object initialized with the contents of the Quartz 2D image and the specified options.

    Import Statement

    Objective-C

    @import CoreImage;

    Availability

    Available in iOS 5.0 and later.

  • Creates and returns an image object from the contents of a file.

    Declaration

    Objective-C

    + (CIImage *)imageWithContentsOfURL:(NSURL *)url

    Parameters

    url

    The location of the file.

    Return Value

    An image object initialized with the contents of the file.

    Import Statement

    Objective-C

    @import CoreImage;

    Availability

    Available in iOS 5.0 and later.

  • Creates and returns an image object from the contents of a file, using the specified options.

    Declaration

    Objective-C

    + (CIImage *)imageWithContentsOfURL:(NSURL *)url options:(NSDictionary *)d

    Parameters

    url

    The location of the file.

    d

    A dictionary specifying image options. (See “Image Dictionary Keys”.)

    Return Value

    An image object initialized with the contents of the file and set up with the specified options.

    Import Statement

    Objective-C

    @import CoreImage;

    Availability

    Available in iOS 5.0 and later.

  • Creates and returns an image object from the contents of CVPixelBuffer object.

    Declaration

    Objective-C

    + (CIImage *)imageWithCVPixelBuffer:(CVPixelBufferRef)buffer

    Parameters

    buffer

    A CVPixelBuffer object.

    Return Value

    An image object initialized with the contents of the image buffer object.

    Import Statement

    Objective-C

    @import CoreImage;

    Availability

    Available in iOS 5.0 and later.

  • Creates and returns an image object from the contents of CVPixelBuffer object, using the specified options.

    Declaration

    Objective-C

    + (CIImage *)imageWithCVPixelBuffer:(CVPixelBufferRef)buffer options:(NSDictionary *)dict

    Parameters

    buffer

    A CVPixelBuffer object.

    dict

    A dictionary specifying image options. (See “Image Dictionary Keys”.)

    Return Value

    An image object initialized with the contents of the image buffer object and set up with the specified options.

    Import Statement

    Objective-C

    @import CoreImage;

    Availability

    Available in iOS 5.0 and later.

  • Creates and returns an image object initialized with the supplied image data.

    Declaration

    Objective-C

    + (CIImage *)imageWithData:(NSData *)data

    Parameters

    data

    The data object that holds the contents of an image file (such as TIFF, GIF, JPG, or whatever else the system supports). The image data must be premultiplied.

    Return Value

    An image object initialized with the supplied data, or nil if the method cannot create an image representation from the contents of the supplied data object.

    Import Statement

    Objective-C

    @import CoreImage;

    Availability

    Available in iOS 5.0 and later.

  • Creates and returns an image object initialized with the supplied image data, using the specified options.

    Declaration

    Objective-C

    + (CIImage *)imageWithData:(NSData *)data options:(NSDictionary *)d

    Parameters

    data

    A pointer to the image data. The data must be premultiplied

    d

    A dictionary specifying image options. (See “Image Dictionary Keys”.)

    Return Value

    An image object initialized with the supplied data and set up with the specified options.

    Import Statement

    Objective-C

    @import CoreImage;

    Availability

    Available in iOS 5.0 and later.

  • Creates and returns an image object initialized with data supplied by an OpenGL texture.

    Declaration

    Objective-C

    + (CIImage *)imageWithTexture:(unsigned int)name size:(CGSize)size flipped:(BOOL)flag colorSpace:(CGColorSpaceRef)cs

    Parameters

    name

    An OpenGL texture. Because CIImage objects are immutable, the texture must remain unchanged for the life of the image object. See the discussion for more information.

    size

    The dimensions of the texture.

    flag

    YEStrue to have Core Image flip the coordinates of the texture vertically to convert between OpenGL and Core Image coordinate systems.

    cs

    The color space that the image is defined in. If the colorSpace value is nil, the image is not color matched. Pass nil for images that don’t contain color data (such as elevation maps, normal vector maps, and sampled function tables).

    Return Value

    An image object initialized with the texture data.

    Discussion

    When using a texture to create a CIImage object, the texture must be valid in the Core Image context (CIContext) that you draw the CIImage object into. This means that one of the following must be true:

    • The texture must be created using the CGLContext object that the CIContext is based on.

    • The context that the texture was created in must be shared with the CGLContext that the CIContext is based on.

    Note that textures do not have a retain and release mechanism. This means that your application must make sure that the texture exists for the life cycle of the image. When you no longer need the image, you can delete the texture.

    Core Image ignores the texture filtering and wrap modes (GL_TEXTURE_FILTER and GL_TEXTURE_WRAP) that you set through OpenGL. The filter and wrap modes are overridden by what the CISampler object specifies when you apply a filter to the CIImage object.

    Import Statement

    Objective-C

    @import CoreImage;

    Availability

    Available in iOS 6.0 and later.

  • Returns a new image created by applying a filter to the original image with the specified name and parameters.

    Declaration

    Swift

    func imageByApplyingFilter(_ filterName: String!, withInputParameters params: [NSObject : AnyObject]!) -> CIImage!

    Objective-C

    - (CIImage *)imageByApplyingFilter:(NSString *)filterName withInputParameters:(NSDictionary *)params

    Parameters

    filterName

    The name of the filter to apply, as used when creating a CIFilter instance with the filterWithName: method.

    params

    A dictionary whose key-value pairs are set as input values to the filter. Each key is a constant that specifies the name of an input parameter for the filter, and the corresponding value is the value for that parameter. See Core Image Filter Reference for built-in filters and their allowed parameters.

    Return Value

    An image object representing the result of applying the filter.

    Discussion

    Calling this method is equivalent to the following sequence of steps:

    1. Creating a CIFilter instance

    2. Setting the original image as the filter’s inputImage parameter

    3. Setting the remaining filter parameters from the params dictionary

    4. Retrieving the outputImage object from the filter

    Import Statement

    Objective-C

    @import CoreImage;

    Swift

    import CoreImage

    Availability

    Available in iOS 8.0 and later.

  • Returns a new image that represents the original image after applying an affine transform.

    Declaration

    Swift

    func imageByApplyingTransform(_ matrix: CGAffineTransform) -> CIImage!

    Objective-C

    - (CIImage *)imageByApplyingTransform:(CGAffineTransform)matrix

    Parameters

    matrix

    An affine transform.

    Return Value

    The transformed image object.

    Import Statement

    Objective-C

    @import CoreImage;

    Swift

    import CoreImage

    Availability

    Available in iOS 5.0 and later.

  • Returns a new image that represents the original image after cropping to a rectangle.

    Declaration

    Swift

    func imageByCroppingToRect(_ r: CGRect) -> CIImage!

    Objective-C

    - (CIImage *)imageByCroppingToRect:(CGRect)r

    Return Value

    An image object cropped to the specified rectangle.

    Import Statement

    Objective-C

    @import CoreImage;

    Swift

    import CoreImage

    Availability

    Available in iOS 5.0 and later.

  • Returns a new image created by transforming the original image to the specified EXIF orientation.

    Declaration

    Swift

    func imageByApplyingOrientation(_ orientation: Int32) -> CIImage!

    Objective-C

    - (CIImage *)imageByApplyingOrientation:(int)orientation

    Parameters

    orientation

    An integer specifying an image orientation according to the EXIF specification. For details, see kCGImagePropertyOrientation.

    Return Value

    An image object representing the result of rotating or mirroring the image to the target orientation.

    Discussion

    This method determines and then applies the transformation needed to reorient the image to the specified orientation. If you plan to also apply other transformations, you can retrieve the transformation this method would use by calling the imageTransformForOrientation: method.

    Import Statement

    Objective-C

    @import CoreImage;

    Swift

    import CoreImage

    Availability

    Available in iOS 8.0 and later.

  • Returns a new image created by clamping the original image so that the pixel colors along its edges extend infinitely in all directions.

    Declaration

    Swift

    func imageByClampingToExtent() -> CIImage!

    Objective-C

    - (CIImage *)imageByClampingToExtent

    Return Value

    An image object representing the result of the clamp operation.

    Discussion

    Calling this method is equivalent to using the CIAffineClamp filter, which creates an image of infinite extent by repeating pixel colors from the edges of the original image.

    This operation can be useful when using the image as input to other filters. When an image has finite extent, Core Image treats the area outside the extent as if it were filled with empty (black, zero alpha) pixels. If you apply a filter that samples from outside the image’s extent, those empty pixels affect the result of the filter.

    For example, applying the CIGaussianBlur filter to an image softens the edges of the blurred image, because the opaque pixels at the edges of the image blur into the transparent pixels outside the image’s extent. Applying a clamp effect before the blur filter avoids edge softening by making the original image opaque in all directions. (However, the blurred image will also have infinite extent. Use the imageByCroppingToRect: method to return to the original image’s dimensions while retaining hard edges.)

    Import Statement

    Objective-C

    @import CoreImage;

    Swift

    import CoreImage

    Availability

    Available in iOS 8.0 and later.

  • Returns a new image created by compositing the original image over the specified destination image.

    Declaration

    Swift

    func imageByCompositingOverImage(_ dest: CIImage!) -> CIImage!

    Objective-C

    - (CIImage *)imageByCompositingOverImage:(CIImage *)dest

    Parameters

    dest

    An image to serve as the destination of the compositing operation.

    Return Value

    An image object representing the result of the compositing operation.

    Discussion

    Calling this method is equivalent to using the CISourceOverCompositing filter. To use other compositing operations and blending modes, create a CIFilter object using one of the built-in filters from the CICategoryCompositeOperation category. For details, see Core Image Filter Reference.

    Import Statement

    Objective-C

    @import CoreImage;

    Swift

    import CoreImage

    Availability

    Available in iOS 8.0 and later.

  • Initializes an image with the specified color.

    Declaration

    Swift

    init!(color color: CIColor!)

    Objective-C

    - (id)initWithColor:(CIColor *)color

    Parameters

    color

    A color object.

    Return Value

    The initialized image object or nil if the object could not be initialized.

    Import Statement

    Objective-C

    @import CoreImage;

    Swift

    import CoreImage

    Availability

    Available in iOS 5.0 and later.

  • Initializes an image object with bitmap data.

    Declaration

    Swift

    init!(bitmapData d: NSData!, bytesPerRow bpr: UInt, size size: CGSize, format f: CIFormat, colorSpace c: CGColorSpace!)

    Objective-C

    - (id)initWithBitmapData:(NSData *)d bytesPerRow:(size_t)bpr size:(CGSize)size format:(CIFormat)f colorSpace:(CGColorSpaceRef)c

    Parameters

    d

    The bitmap data to use for the image. The data you supply must be premultiplied.

    bpr

    The number of bytes per row.

    size

    The size of the image data.

    f

    A pixel format constant. See “Pixel Formats”.

    c

    The color space that the image is defined in and must be a Quartz 2D color space (CGColorSpaceRef). Pass nil for images that don’t contain color data (such as elevation maps, normal vector maps, and sampled function tables).

    Return Value

    The initialized image object or nil if the object could not be initialized.

    Import Statement

    Objective-C

    @import CoreImage;

    Swift

    import CoreImage

    Availability

    Available in iOS 5.0 and later.

  • Initializes an image object with a Quartz 2D image.

    Declaration

    Swift

    init!(CGImage image: CGImage!)

    Objective-C

    - (id)initWithCGImage:(CGImageRef)image

    Parameters

    image

    A Quartz 2D image (CGImageRef) object. For more information, see Quartz 2D Programming Guide and CGImage Reference.

    Return Value

    The initialized image object or nil if the object could not be initialized.

    Import Statement

    Objective-C

    @import CoreImage;

    Swift

    import CoreImage

    Availability

    Available in iOS 5.0 and later.

  • Initializes an image object with a Quartz 2D image, using the specified options.

    Declaration

    Swift

    init!(CGImage image: CGImage!, options d: [NSObject : AnyObject]!)

    Objective-C

    - (id)initWithCGImage:(CGImageRef)image options:(NSDictionary *)d

    Parameters

    image

    A Quartz 2D image (CGImageRef) object. For more information, see Quartz 2D Programming Guide and CGImage Reference.

    d

    A dictionary specifying image options. (See “Image Dictionary Keys”.)

    Return Value

    The initialized image object or nil if the object could not be initialized.

    Import Statement

    Objective-C

    @import CoreImage;

    Swift

    import CoreImage

    Availability

    Available in iOS 5.0 and later.

  • Initializes an image object with the specified UIKit image object.

    Declaration

    Swift

    init!(image image: UIImage!)

    Objective-C

    - (instancetype)initWithImage:(UIImage *)image

    Parameters

    image

    An image containing the source data.

    Return Value

    The initialized image object or nil if the object could not be initialized.

    Import Statement

    Objective-C

    @import UIKit;

    Swift

    import UIKit

    Availability

    Available in iOS 5.0 and later.

  • Initializes an image object with the specified UIKit image object, using the specified options.

    Declaration

    Swift

    init!(image image: UIImage!, options options: [NSObject : AnyObject]!)

    Objective-C

    - (instancetype)initWithImage:(UIImage *)image options:(NSDictionary *)options

    Parameters

    image

    An image containing the source data.

    options

    A dictionary that contains options for creating an image object. You can supply such options as a pixel format and a color space. See “Image Dictionary Keys”.

    Return Value

    The initialized image object or nil if the object could not be initialized.

    Import Statement

    Objective-C

    @import UIKit;

    Swift

    import UIKit

    Availability

    Available in iOS 5.0 and later.

  • Initializes an image object by reading an image from a URL.

    Declaration

    Swift

    init!(contentsOfURL url: NSURL!)

    Objective-C

    - (id)initWithContentsOfURL:(NSURL *)url

    Parameters

    url

    The location of the image file to read.

    Return Value

    The initialized image object or nil if the object could not be initialized.

    Import Statement

    Objective-C

    @import CoreImage;

    Swift

    import CoreImage

    Availability

    Available in iOS 5.0 and later.

  • Initializes an image object by reading an image from a URL, using the specified options.

    Declaration

    Swift

    init!(contentsOfURL url: NSURL!, options d: [NSObject : AnyObject]!)

    Objective-C

    - (id)initWithContentsOfURL:(NSURL *)url options:(NSDictionary *)d

    Parameters

    url

    The location of the image file to read.

    d

    A dictionary specifying image options. (See “Image Dictionary Keys”.)

    Return Value

    The initialized image object or nil if the object could not be initialized.

    Import Statement

    Objective-C

    @import CoreImage;

    Swift

    import CoreImage

    Availability

    Available in iOS 5.0 and later.

  • Initializes an image object from the contents of CVPixelBuffer object.

    Declaration

    Swift

    init!(CVPixelBuffer buffer: CVPixelBuffer!)

    Objective-C

    - (id)initWithCVPixelBuffer:(CVPixelBufferRef)buffer

    Parameters

    buffer

    A CVPixelBuffer object.

    Return Value

    The initialized image object or nil if the object could not be initialized.

    Import Statement

    Objective-C

    @import CoreImage;

    Swift

    import CoreImage

    Availability

    Available in iOS 5.0 and later.

  • Initializes an image object from the contents of CVPixelBuffer object using the specified options.

    Declaration

    Swift

    init!(CVPixelBuffer buffer: CVPixelBuffer!, options dict: [NSObject : AnyObject]!)

    Objective-C

    - (id)initWithCVPixelBuffer:(CVPixelBufferRef)buffer options:(NSDictionary *)dict

    Parameters

    buffer

    A CVPixelBuffer object.

    dict

    A dictionary that contains options for creating an image object. (See “Image Dictionary Keys”.) The pixel format is supplied by the CVPixelBuffer object.

    Return Value

    The initialized image object or nil if the object could not be initialized.

    Import Statement

    Objective-C

    @import CoreImage;

    Swift

    import CoreImage

    Availability

    Available in iOS 5.0 and later.

  • Initializes an image object with the supplied image data.

    Declaration

    Swift

    init!(data data: NSData!)

    Objective-C

    - (id)initWithData:(NSData *)data

    Parameters

    data

    The image data. The data you supply must be premultiplied.

    Return Value

    The initialized image object or nil if the object could not be initialized.

    Import Statement

    Objective-C

    @import CoreImage;

    Swift

    import CoreImage

    Availability

    Available in iOS 5.0 and later.

  • Initializes an image object with the supplied image data, using the specified options.

    Declaration

    Swift

    init!(data data: NSData!, options d: [NSObject : AnyObject]!)

    Objective-C

    - (id)initWithData:(NSData *)data options:(NSDictionary *)d

    Parameters

    data

    The image data. The data you supply must be premultiplied.

    d

    A dictionary specifying image options. (See “Image Dictionary Keys”.)

    Return Value

    The initialized image object or nil if the object could not be initialized.

    Import Statement

    Objective-C

    @import CoreImage;

    Swift

    import CoreImage

    Availability

    Available in iOS 5.0 and later.

  • Initializes an image object with data supplied by an OpenGL texture.

    Declaration

    Swift

    init!(texture name: UInt32, size size: CGSize, flipped flag: Bool, colorSpace cs: CGColorSpace!)

    Objective-C

    - (id)initWithTexture:(unsigned int)name size:(CGSize)size flipped:(BOOL)flag colorSpace:(CGColorSpaceRef)cs

    Parameters

    name

    An OpenGL texture. Because CIImage objects are immutable, the texture must remain unchanged for the life of the image object. See the discussion for more information.

    size

    The dimensions of the texture.

    flag

    YEStrue to have Core Image flip the coordinates of the texture vertically to convert between OpenGL and Core Image coordinate systems.

    cs

    The color space that the image is defined in. This must be a Quartz color space (CGColorSpaceRef). If the colorSpace value is nil, the image is not color matched. Pass nil for images that don’t contain color data (such as elevation maps, normal vector maps, and sampled function tables).

    Return Value

    The initialized image object or nil if the object could not be initialized.

    Discussion

    When using a texture to create a CIImage object, the texture must be valid in the Core Image context (CIContext) that you draw the CIImage object into. This means that one of the following must be true:

    • The texture must be created using the CGLContext object that the CIContext is based on.

    • The context that the texture was created in must be shared with the CGLContext that the CIContextis based on.

    Note that textures do not have a retain and release mechanism. This means that your application must make sure that the texture exists for the life cycle of the image. When you no longer need the image, you can delete the texture.

    Core Image ignores the texture filtering and wrap modes (GL_TEXTURE_FILTER and GL_TEXTURE_WRAP) that you set through OpenGL. The filter and wrap modes are overridden by what the CISampler object specifies when you apply a filter to the CIImage object.

    Import Statement

    Objective-C

    @import CoreImage;

    Swift

    import CoreImage

    Availability

    Available in iOS 6.0 and later.

  • Returns a rectangle that specifies the extent of the image.

    Declaration

    Swift

    func extent() -> CGRect

    Objective-C

    - (CGRect)extent

    Return Value

    A rectangle that specifies the extent of the image in working space coordinates.

    Import Statement

    Objective-C

    @import CoreImage;

    Swift

    import CoreImage

    Availability

    Available in iOS 5.0 and later.

  • Returns a dictionary containing image metadata.

    Declaration

    Swift

    func properties() -> [NSObject : AnyObject]!

    Objective-C

    - (NSDictionary *)properties

    Return Value

    An NSDictionary object containing image metadata.

    Discussion

    If the CIImage object is the output of a filter (or filter chain), this method returns the metadata from the filter’s original input image.

    Import Statement

    Objective-C

    @import CoreImage;

    Swift

    import CoreImage

    Availability

    Available in iOS 5.0 and later.

  • Returns the transformation needed to reorient the image to the specified orientation.

    Declaration

    Swift

    func imageTransformForOrientation(_ orientation: Int32) -> CGAffineTransform

    Objective-C

    - (CGAffineTransform)imageTransformForOrientation:(int)orientation

    Parameters

    orientation

    An integer specifying an image orientation according to the EXIF specification. For details, see kCGImagePropertyOrientation.

    Return Value

    An affine transform that will rotate or mirror the image to match the specified orientation when applied.

    Discussion

    This method determines the transformation needed to match the specified orientation, but does not apply that transformation to the image. To apply the transformation (possibly after concatenating it with other transformations), use the imageByApplyingTransform: method or the CIAffineTransform filter. To determine and apply the transformation in a single step, use the imageByApplyingOrientation: method.

    Import Statement

    Objective-C

    @import CoreImage;

    Swift

    import CoreImage

    Availability

    Available in iOS 8.0 and later.

  • Returns all possible automatically selected and configured filters for adjusting the image.

    Declaration

    Swift

    func autoAdjustmentFilters() -> [AnyObject]!

    Objective-C

    - (NSArray *)autoAdjustmentFilters

    Return Value

    An array of CIFilter instances preconfigured for correcting deficiencies in the supplied image.

    Import Statement

    Objective-C

    @import CoreImage;

    Swift

    import CoreImage

    Availability

    Available in iOS 5.0 and later.

  • Returns a subset of automatically selected and configured filters for adjusting the image.

    Declaration

    Swift

    func autoAdjustmentFiltersWithOptions(_ options: [NSObject : AnyObject]!) -> [AnyObject]!

    Objective-C

    - (NSArray *)autoAdjustmentFiltersWithOptions:(NSDictionary *)options

    Parameters

    options

    You can control which filters are returned by supplying one or more of the keys described in Autoadjustment Keys.

    The options dictionary can also contain a CIDetectorImageOrientation key. Because some autoadjustment filters rely on face detection, you should specify an image orientation if you want to enable these filters for an image containing face whose orientation does not match that of the image.

    Return Value

    An array of CIFilter instances preconfigured for correcting deficiencies in the supplied image.

    Import Statement

    Objective-C

    @import CoreImage;

    Swift

    import CoreImage

    Availability

    Available in iOS 5.0 and later.

  • Returns the region of interest for the filter chain that generates the image.

    Declaration

    Swift

    func regionOfInterestForImage(_ im: CIImage!, inRect r: CGRect) -> CGRect

    Objective-C

    - (CGRect)regionOfInterestForImage:(CIImage *)im inRect:(CGRect)r

    Parameters

    im

    Another image that is part of the filter chain that generates the image.

    r

    A rectangle in the image’s coordinate space.

    Return Value

    A rectangle in the coordinate space of the input image (the im parameter).

    Discussion

    The region of interest is the rectangle containing pixel data in a source image (the im parameter) necessary to produce a corresponding rectangle in the output image. If the image is not the output of a filter (or of a chain or graph of several CIFilter objects), or the image in the im parameter is not an input to that filter, the rectangle returned is the same as that in the r parameter.

    For example,

    • If the image is the output of a filter that doubles the size of its input image, the rectangle returned will be half the size of that in the r parameter. (Upscaling causes every pixel in the input image to correspond to multiple pixels in the output image.)

    • If the image is the output of a blur filter, the rectangle returned will be slightly larger than that in the r parameter. (In a blur filter, each pixel in the output image is produced using information from the corresponding pixel and those immediately surrounding it in the input image.)

    Import Statement

    Objective-C

    @import CoreImage;

    Swift

    import CoreImage

    Availability

    Available in iOS 6.0 and later.

Data Types

  • A data type used for specifying image pixel formats.

    Declaration

    Swift

    typealias CIFormat = Int32

    Objective-C

    typedef int CIFormat;

    Import Statement

    Objective-C

    @import CoreImage;

    Swift

    import CoreImage

    Availability

    Available in iOS 5.0 and later.

  • Image data pixel formats.

    Declaration

    Swift

    var kCIFormatARGB8: CIFormat var kCIFormatBGRA8: CIFormat var kCIFormatRGBA8: CIFormat

    Objective-C

    extern CIFormat kCIFormatARGB8; extern CIFormat kCIFormatBGRA8; extern CIFormat kCIFormatRGBA8;

    Constants

    • kCIFormatARGB8

      kCIFormatARGB8

      A 32 bit-per-pixel, fixed-point pixel format in which the alpha value precedes the red, green and blue color components.

      Available in iOS 6.0 and later.

    • kCIFormatBGRA8

      kCIFormatBGRA8

      A 32 bit-per-pixel, fixed-point pixel format in which the blue, green, and red color components precede the alpha value.

      Available in iOS 5.0 and later.

    • kCIFormatRGBA8

      kCIFormatRGBA8

      A 32 bit-per-pixel, fixed-point pixel format in which the red, green, and blue color components precede the alpha value.

      Available in iOS 5.0 and later.

  • Constants used as keys in the options dictionary when initializing an image.

    Declaration

    Swift

    var kCIImageColorSpace: NSString! var kCIImageProperties: NSString!

    Objective-C

    extern NSString *kCIImageColorSpace; extern NSString *kCIImageProperties;

    Constants

    • kCIImageColorSpace

      kCIImageColorSpace

      The key for a color space.

      For more information on this data type see CGColorSpace Reference. Typically you use this option when you need to load an elevation, mask, normal vector, or RAW sensor data directly from a file without color correcting it. This constant specifies to override Core Image, which, by default, assumes that data is in GenericRGB.

      To request that Core Image perform no color management, specify the NSNull object as the value for this key. Use this option for images that don’t contain color data (such as elevation maps, normal vector maps, and sampled function tables).

      Available in iOS 5.0 and later.

    • kCIImageProperties

      kCIImageProperties

      The key for image metadata properties.

      The value you supply for this dictionary key must be a CGColorSpaceRef data type. If a value for this key isn’t supplied, the image’s colorSpace dictionary are populated automatically by calling CGImageSourceCopyPropertiesAtIndex. To ensure that an image has no metadata properties, set the value of this key to [NSNull null].

      Available in iOS 5.0 and later.

  • Constants used as keys in the options dictionary for the autoAdjustmentFiltersWithOptions: method.

    Declaration

    Swift

    var kCIImageAutoAdjustEnhance: NSString! var kCIImageAutoAdjustRedEye: NSString! var kCIImageAutoAdjustFeatures: NSString! var kCIImageAutoAdjustCrop: NSString! var kCIImageAutoAdjustLevel: NSString!

    Objective-C

    NSString *kCIImageAutoAdjustEnhance; NSString *kCIImageAutoAdjustRedEye; NSString *kCIImageAutoAdjustFeatures; NSString *kCIImageAutoAdjustCrop; NSString *kCIImageAutoAdjustLevel;

    Constants

    • kCIImageAutoAdjustEnhance

      kCIImageAutoAdjustEnhance

      A key used to specify whether to return enhancement filters.

      The value associated with this key is a CFBoolean value. Supply false to indicate not to return enhancement filters. If you don’t specify this option, Core Image assumes its value is true.

      Available in iOS 5.0 and later.

    • kCIImageAutoAdjustRedEye

      kCIImageAutoAdjustRedEye

      A key used to specify whether to return a red eye filter.

      The value associated with this key is a CFBoolean value. Supply false to indicate not to return a red eye filter. If you don’t specify this option, Core Image assumes its value is true.

      Available in iOS 5.0 and later.

    • kCIImageAutoAdjustFeatures

      kCIImageAutoAdjustFeatures

      A key used to specify an array of features that you want to apply enhancement and red eye filters to.

      The associated value is an array of CIFeature objects. If you don’t supply an array, the Core Image searches for features using the CIDetector class.

      Available in iOS 5.0 and later.

    • kCIImageAutoAdjustCrop

      kCIImageAutoAdjustCrop

      A key used to specify whether to return a filter that crops the image to focus on detected features.

      The value associated with this key is a CFBoolean value. If true, the returned filters include an operation that crops the image around the features specified with the kCIImageAutoAdjustFeatures option (or any features detected in the image, if that option is not present). Supply false to indicate not to return a crop filter. If you don’t specify this option, Core Image assumes its value is false.

      Available in iOS 8.0 and later.

    • kCIImageAutoAdjustLevel

      kCIImageAutoAdjustLevel

      A key used to specify whether to return a filter that rotates the image to keep a level perspective.

      The value associated with this key is a CFBoolean value. If true, Core Image analyzes the image to determine whether it would benefit from rotation—for example, a landscape photo in which the horizon is not horizontal—and returns a filter to perform that rotation. Supply false to indicate not to return a rotation filter. If you don’t specify this option, Core Image assumes its value is false.

      Available in iOS 8.0 and later.