Use ProgressiveDisplay to turn on or off the incremental display of an image when reading in files. For example, if the jpeg data source file is on the hard drive, progressively displaying it slows down the display time: in this case setting ProgressiveDisplay to false speeds up the displaying of the image. If the file must be downloaded, set ProgressiveDisplay to true if the downloading process will take as long as the progressive displaying of the image. 

ProgressiveDisplay is used only for decompression, but is affected by the manner in which the image was compressed. Images that were compressed with ProgressiveEncoding set to false cannot take advantage of ProgressiveDisplay. Setting ProgressiveDisplay to true for these images has no effect. 

ProgressiveEncoding 

Smoothing