Hello Tom,

it is rather straightforward:

* in Encapsulated Syntaxes (compressed JPEG, for example), look at the
Syntax Description in Part 5 PS3.5-2008 (Hint: most is OB ) )

* in non encapsulated, non-compressed Syntaxes, look at the "Bits
Allocated" (0028,0100).

If you have 8 bit Image data, changing it to "OW" means, you read 2
Pixels at once - this will result in rather psychedelic display.

Hope this helps,


Peter


tom.marynowski@gmail.com wrote:
> Hello,
>
> i have read :
>
> The Pixel Data Element (7FE0,0010) has a VR of OW or OB, depending on
> the negotiated Transfer Syntax.
> The only difference between OW and OB being that OB, a string of
> bytes, shall be unaffected by Byte Ordering.
>
> i think information about ow ob are in PS 3.3 .. but i was be able to
> found informations about that.
>
> i would know when ow or ob must be used.
> i would know if during writing file received form remote pacs , an
> original file in OB is transformed into OW depending the writing
> transfert syntax. and if OW will stay in OW. the bit number is
> important or not (8 bit , 6 bit ) ?
> i would know if changing VR from OB to OW corrupt the pixeldata ??
>
> thanks