A key for the scale factor. The associated value is a floating-point value packaged as an NSNumber object that specifies the desired scale factor at which the image will be drawn. Setting this value can greatly improve the drawing performance. A value of 1 is the identity. In some cases, if you change the scale factor and enable draft mode, performance can decrease. See kCIAllowDraftModeKey.
Available in Mac OS X v10.5 and later.
Declaration Syntax Version Information- Available in Monobjc Bridge: 10.6 (For Mac OS X 10.6 and later), 10.5 (For Mac OS X 10.5 and later)