---
title: kCGImageSourceTypeIdentifierHint
framework: imageio
role: symbol
role_heading: Global Variable
path: imageio/kcgimagesourcetypeidentifierhint
---

# kCGImageSourceTypeIdentifierHint

The uniform type identifier that represents your best guess for the image’s type.

## Declaration

```swift
let kCGImageSourceTypeIdentifierHint: CFString
```

## Discussion

Discussion The value of this key is a CFString object. Add this key to the options dictionary when you create a CGImageSource object.

## See Also

### Specifying the Read Options

- [kCGImageSourceShouldAllowFloat](imageio/kcgimagesourceshouldallowfloat.md)
- [kCGImageSourceShouldCache](imageio/kcgimagesourceshouldcache.md)
- [kCGImageSourceShouldCacheImmediately](imageio/kcgimagesourceshouldcacheimmediately.md)
- [kCGImageSourceCreateThumbnailFromImageIfAbsent](imageio/kcgimagesourcecreatethumbnailfromimageifabsent.md)
- [kCGImageSourceCreateThumbnailFromImageAlways](imageio/kcgimagesourcecreatethumbnailfromimagealways.md)
- [kCGImageSourceThumbnailMaxPixelSize](imageio/kcgimagesourcethumbnailmaxpixelsize.md)
- [kCGImageSourceCreateThumbnailWithTransform](imageio/kcgimagesourcecreatethumbnailwithtransform.md)
- [kCGImageSourceSubsampleFactor](imageio/kcgimagesourcesubsamplefactor.md)