Declarationproperty JPEG_DCTMethod: TIOJPEGDCTMethod;
Specifies the DCT method used for reading and writing JPEG images.
Generally, ioJPEG_ISLOW is used for better quality, though it is slightly slower than ioJPEG_IFAST. ioJPEG_FLOAT should theoretically provide the best quality, though the difference is minor and it is slower.
Default: ioJPEG_ISLOW (Specified by IOParamDefaults