Contents

kCGImageSourceCreateThumbnailFromImageIfAbsent

A Boolean value that indicates whether to create a thumbnail image automatically if the data source doesn’t contain one.

Declaration

let kCGImageSourceCreateThumbnailFromImageIfAbsent: CFString

Discussion

The value of this key is a CFBoolean. The default value is kCFBooleanFalse.

If you set the value of this key to kCFBooleanTrue, the image source creates the thumbnail from the full image, subject to the limit specified by kCGImageSourceThumbnailMaxPixelSize. If you don’t specify a maximum pixel size, the image soucre creates the thumbnail using the image’s full size, which in most cases is not desirable.

Include this key in the options dictionary you pass to the function CGImageSourceCreateThumbnailAtIndex(_:_:_:).

See Also

Specifying the Read Options