---
title: Core Graphics interoperability
framework: accelerate
role: collectionGroup
role_heading: API Collection
path: accelerate/core-graphics-interoperability
---

# Core Graphics interoperability

Pass image data between the Core Graphics framework and the vImage library.

## Overview

Overview The vImage library uses the CGImage class as the main type to consume and produce still images. A CGImage instance may originate from NSImage or UIImage images, or from a CGContext drawing destination. A typical Core Graphics-based vImage workflow consists of: Selecting a source image, such as a Core Graphics-backed UIImage instance. Initializing a vImage buffer from the image’s bitmap data. Performing an operation on the vImage buffer, such as scaling or adjusting gamma. Creating a destination image from the operation result with the same image format as the source image. vImage provides the following functions that simplify interoperation with Core Graphics: vImageBuffer_InitWithCGImage(_:_:_:_:_:) initializes a vImage buffer with the contents of a Core Graphics image. vImageCreateCGImageFromBuffer(_:_:_:_:_:_:) creates a Core Graphics image from a vImage buffer. The following code shows a passthrough function that accepts a CGImage image, populates a vImage buffer from the image, and generates a CGImage image from the buffer. In this example, the call to vImageBuffer_InitWithCGImage(_:_:_:_:_:) populates the vImage_CGImageFormat and the vImage_Buffer variables with the properties of the source image: static func passThrough(sourceImage: CGImage) -> CGImage? {

var format = vImage_CGImageFormat()     var buffer = vImage_Buffer()          defer {         buffer.free()     }

vImageBuffer_InitWithCGImage(         &buffer,         &format,         nil,         sourceImage,         vImage_Flags(kvImageNoFlags))         // Perform image-processing operations on `buffer`.

let destinationCGImage = vImageCreateCGImageFromBuffer(         &buffer,         &format,         nil,         nil,         vImage_Flags(kvImageNoFlags),         nil)          return destinationCGImage?.takeRetainedValue() } Pass a fully initialized vImage_CGImageFormat to specify that vImageBuffer_InitWithCGImage(_:_:_:_:_:) converts the source CGImage image to the format that format describes. The following example converts the source image to a three-channel, 8-bit-per-channel RGB image: static func passThrough(sourceImage: CGImage) -> CGImage? {          var format = vImage_CGImageFormat(         bitsPerComponent: 8,         bitsPerPixel: 8 * 3,         colorSpace: CGColorSpaceCreateDeviceRGB(),         bitmapInfo: CGBitmapInfo(rawValue: CGImageAlphaInfo.none.rawValue),         renderingIntent: .defaultIntent)!

var buffer = vImage_Buffer()

defer {         buffer.free()     }          vImageBuffer_InitWithCGImage(         &buffer,         &format,         nil,         sourceImage,         vImage_Flags(kvImageNoFlags))          // Perform image-processing operations on RGB888 `buffer`.

let destinationCGImage = vImageCreateCGImageFromBuffer(         &buffer,         &format,         nil,         nil,         vImage_Flags(kvImageNoFlags),         nil)          return destinationCGImage?.takeRetainedValue() }

## Topics

### Initializing vImage buffers from Core Graphics images

- [vImageBuffer_InitWithCGImage(_:_:_:_:_:)](accelerate/vimagebuffer_initwithcgimage(_:_:_:_:_:).md)

### Creating Core Graphics images from vImage buffers

- [vImageCreateCGImageFromBuffer(_:_:_:_:_:_:)](accelerate/vimagecreatecgimagefrombuffer(_:_:_:_:_:_:).md)

### Creating Core Graphics image formats

- [vImage_CGImageFormat](accelerate/vimage_cgimageformat.md)

### Querying Core Graphics image format attributes

- [vImageCGImageFormat_IsEqual(_:_:)](accelerate/vimagecgimageformat_isequal(_:_:).md)
- [vImageCGImageFormat_GetComponentCount(_:)](accelerate/vimagecgimageformat_getcomponentcount(_:).md)

### Creating Core Graphics color spaces

- [vImageCreateRGBColorSpaceWithPrimariesAndTransferFunction(_:_:_:_:_:)](accelerate/vimagecreatergbcolorspacewithprimariesandtransferfunction(_:_:_:_:_:).md)
- [vImageRGBPrimaries](accelerate/vimagergbprimaries.md)
- [vImageTransferFunction](accelerate/vimagetransferfunction.md)
- [vImageCreateMonochromeColorSpaceWithWhitePointAndTransferFunction(_:_:_:_:_:)](accelerate/vimagecreatemonochromecolorspacewithwhitepointandtransferfunction(_:_:_:_:_:).md)
- [vImageWhitePoint](accelerate/vimagewhitepoint.md)