qlmanage as preview generation mechanism

mavericks-mini:Desktop admin$ qlmanage -z -t -s 1024x1024 -o /Users/Shared 5N2A0401.CR2
.
Thumbnails produced: 1
Duration: 0.357198 seconds (average 0.357198 seconds per file)

mavericks-mini:Desktop admin$ mdls /Users/Shared/5N2A0401.CR2.png
kMDItemBitsPerSample           = 40
kMDItemColorSpace              = "RGB"
kMDItemContentCreationDate     = 2014-02-17 09:49:26 +0000
kMDItemContentModificationDate = 2014-02-17 09:49:26 +0000
kMDItemContentType             = "public.png"
kMDItemContentTypeTree         = (
    "public.png",
    "public.image",
    "public.data",
    "public.item",
    "public.content"
)
kMDItemDateAdded               = 2014-02-17 09:49:26 +0000
kMDItemDisplayName             = "5N2A0401.CR2.png"
kMDItemFSContentChangeDate     = 2014-02-17 09:49:26 +0000
kMDItemFSCreationDate          = 2014-02-17 09:49:26 +0000
kMDItemFSCreatorCode           = ""
kMDItemFSFinderFlags           = 0
kMDItemFSHasCustomIcon         = (null)
kMDItemFSInvisible             = 0
kMDItemFSIsExtensionHidden     = 0
kMDItemFSIsStationery          = (null)
kMDItemFSLabel                 = 0
kMDItemFSName                  = "5N2A0401.CR2.png"
kMDItemFSNodeCount             = (null)
kMDItemFSOwnerGroupID          = 0
kMDItemFSOwnerUserID           = 501
kMDItemFSSize                  = 1758463
kMDItemFSTypeCode              = ""
kMDItemHasAlphaChannel         = 1
kMDItemKind                    = "PNG-Bild (Portable Network Graphics)"
kMDItemLogicalSize             = 1758463
kMDItemOrientation             = 0
kMDItemPhysicalSize            = 1761280
kMDItemPixelCount              = 698368
kMDItemPixelHeight             = 682
kMDItemPixelWidth              = 1024
kMDItemProfileName             = "Allgemeines RGB-Profil"
kMDItemResolutionHeightDPI     = 0
kMDItemResolutionWidthDPI      = 0