Compression level when
saving the image.
type TCompressionLevel = 0..9;
property CompressionLevel: TCompressionLevel;
Description
To save images, currently Portable Network Graphics uses a
compression technique called ZLIB. ZLIB allows setting the compression
level when compressing images, this allows smaller data but with some
speed lost. Set this property to a higher value to compress better and to
a low value to compress fastest.