A key whose value indicates whether the result image is a low-quality substitute for the requested image.
- iOS 8.0+
- macOS 10.13+
- tvOS 10.0+
This key provides information about an image loading result in the
result block for methods listed in Requesting Images. The corresponding value is an
NSNumber object containing a Boolean value.If
result parameter of your
result block contains a low-quality image because Photos could not yet provide a higher-quality image. Depending on your settings in the
PHImage object that you provided with the request, Photos may call your result handler block again to provide a higher-quality image.