Contents

kCGImagePropertyPNGCompressionFilter

The PNG filter to apply prior to compression.

Declaration

let kCGImagePropertyPNGCompressionFilter: CFString

Discussion

The value of this key is a CFNumber. The number contains a bitwise-OR of one or more filter constants, such as IMAGEIO_PNG_FILTER_AVG or IMAGEIO_PNG_FILTER_SUB. The value has no effect on formats other than PNG.

See Also

Pre-Compression Filters