CODEWITHSUNDEEP
dicom
ShrinivasD
ShrinivasD

Reputation: 63

Dicom VR OB and OW max value length

I would like to know what is the max size of the value length field for the VR OB and OW. I know that currently its 2^32(32 bit application).I want to know in 64 bit application it will be 64 bit? I referred dicom standard(DICOM PS3.5 2014c - Data Structures and Encoding). I did not get any clue. Since we want to store the huge non image data (more than 4gb) I would like to know if that is possible.

Thanks in advance.

Upvotes: 4

Views: 2396

Answers (2)

Marius Herzog
Marius Herzog

Reputation: 597

Although the maximum size of an attribute is 0xfffffffe, in the image data attribute (0x7fe0, 0x0010) larger data can be stored by using an encapsulated transfer syntax. This effectively lets you split up your image data into multiple "items" called fragments. Each fragment also has a maximum size of 0xfffffffe, but there is no limitation to the number of fragments in the image data attribute.

Refer to chapter 5, annex A.4 "Transfer Syntaxes For Encapsulation of Encoded Pixel Data" of the DICOM Standard for detailed explanation.

If you use a library also take a look at their documentation, lots of libraries, for example dcmtk, do support splitting an image into multiple frames. Just look for keywords like fragment or encapsulation.

Upvotes: 3

Paolo Brandoli
Paolo Brandoli

Reputation: 4750

The maximum size of the tag is dictated by the DICOM standard, not by the CPU architecture on which the DICOM library is compiled or used.

At the moment the maximum size (in bytes) of a OB or OW tag is represented by a 32-bit wide value (minus 1 or 2 because 0xFFFFFFFF is reserved).

Upvotes: 2

Related Questions