/Export-Image {/SourceImageFile: | /SWMFile: ]} {/SourceIndex: | /SourceName: } /DestinationImageFile: /DestinationName: ...

/Export-Image {/SourceImageFile: | [/SWMFile:]}
  {/SourceIndex: | /SourceName:} 
  /DestinationImageFile: [/DestinationName:] 
  [/Compress:{fast|max|none|recovery}] [/Bootable] [/CheckIntegrity] 

  Exports a copy of the specified image to another file. The source and 
  destination files must use the same compression type. 
  Use /SWMFile to reference split WIM files (SWMs).  is the naming 
  pattern and location of split files. 
  Use /Compress to specify the type of compression used for the capture 
  operation when exporting an image to a new WIM file. 
  Use /Bootable to mark a Windows PE volume image as able to be booted. 
  Use /CheckIntegrity to detect and track WIM file corruption. 

      DISM.exe /Export-Image /SourceImageFile:install.wim /SourceIndex:1