pub unsafe static ICImageSourceThumbnailMaxPixelSize: &'static ICCameraItemThumbnailOptionICCameraItem only.Expand description
Use of this key will override any custom thumbnail size requested, ignoring the ICImageSourceThumbnailMaxPixelSize option entirely.
Use of this key will be ignored if ICImageSourceShouldCache has also been passed in. Custom thumbnail requests will never be cached.
Only the embedded EXIF thumbnail, or a created thumbnail of EXIF standard size (160x120) will be cached. Use of the ICImageSourceShouldCache flag is discouraged, as the framework shall not act as a backing store out of convienence.
If use of this flag is required, it is highly recommeded to only keep the image cached within the framework temporarily, using the method -[ICCameraItem flushThumbnailCache] to evict the thumbnail.
Multiple calls to both cache the EXIF thumbnail, and subsequently retrieve a larger thumbnail will work as defined.
See also Apple’s documentation