function DoPreviews(pp: TPreviewParams = [ppAll]): boolean;
Description
Executes the Previews dialog allowing the user to review and modify the parameters of image file formats (for example, JPEG quality, TIFF compression, etc).
pp is the set of image formats parameters to show in the dialog.
The style of the dialog is affected by SimplifiedParamsDialogs
The Parameters dialog for TIFF, using SimplifiedParamsDialogs = True;
The Parameters dialog for TIFF, using SimplifiedParamsDialogs = False;