cMove with implicit format conversions or not !

[tom]

Hello !

what is exactly the "implicit format convertion". I can see the case with one the dicom format will be converted. ??

The "format convertion" include transfert syntaxe or just compression data or some think else??

What is the differante between :

("--bit-preserving", "+B", "write data exactly as read");
and
("--write-xfer-same", "+t=", "write with same TS as input (default)");????


if i use cmove fonction to download study, and i want send this same study ( using cstore scu ) i would know if i must change the study/serie UID ? I suppose if the format is changed i need ..


Thanks

[Michael Onken]

Hi Tom,

("--bit-preserving", "+B", "write data exactly as read");
and
("--write-xfer-same", "+t=", "write with same TS as input (default)");????

The first option writes the dataset received bit for bit onto the harddisk. That means that some stuff like padding of attribute values (e. g. trailing spaces in attribut Patients Name) are not changed (and even not corrected if wrongly encoded) before writing to disk. Note that also with changing the padding or e. g. changing the sequence encoding (with or without explicit length) the semantic of the object stays the same! Padding etc. is not negotiated in a DICOM network connection but can differ from object to object and also within one object. So each application has to support all encoding options when reading DICOM objects.

The second option is about the transfer syntax the file should be written onto the disk. The transfer syntax also only reflects a syntactical encoding of the object and has nothing to do with the semantic of the file. You can convert between transfer syntaxes without changing the meaning of the object (Exception: you convert to a transfer syntax with lossy image compression). Because the transfer syntax is negotiated with the DICOM network connection, an application not understanding a specific transfer syntax can reject a connnection offering only unsupported transfer syntaxes.

if i use cmove fonction to download study, and i want send this same study ( using cstore scu ) i would know if i must change the study/serie UID ? I suppose if the format is changed i need ..

No, you don't need to change them. DICOM states that new UIDs must be generated if the medical interpretation of the image changes. When changing the transfer syntax (at least when changing between the uncompressed ones), this is not the case.

Regards,
Michael