DICOM bytewise doubts

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pedro.duarte.pt
Posts: 2
Joined: Mon May 27, 2013 2:50 pm

DICOM bytewise doubts

Post by pedro.duarte.pt » Mon May 27, 2013 3:21 pm

Hello guys,

not sure if this is the right forum but based on the title "Discussion Forum for DICOM software" seems like it.
I was reading through tutorials and standards and I have to admit that I dont understand a few things regarding the basic element structure. Maybe you can help me.

1) Group 2. In group 2 it looks like the structure of the (0x02, 0x01) is not correct. This is a dump starting at "DICM" caracters:
44 49 43 4d 02 00 00 00 55 4c 04 00 c0 00 00 00 02 00 01 00 4f 42 00 00 02 00 00 00 00 01 02 00 02 00 55 49.

analysis:
44 49 43 4d - DICM
02 00 00 00 - Group 2, element 0
55 4c - VR = UL
04 00 - 4 bytes of length info
c0 00 00 00 - length of group 2 (C0 bytes)
02 00 01 00 - Group 2, element 1
4f 42 - VR = OB
00 00 - 0 bytes of length info (?!?!)
02 00 00 00 - Group 2, element 0 (again?!)
00 01 - VR = 01 (?!?!)
No length info (?!?!)
02 00 02 00 - Group 2, element 2 (it goes ok from now on)

So based on my analysis up there either I am not reading correctly group 2 element 1, or there is another problem that I dont understand.
Isn't the structure of all elements in group 2 GROUP -> ELEMENT -> VR -> LENGTH -> VALUE ? Do why the nonesense after ( 0002,0001)?

2) Group (2800,0000)

when I reach this point in most DICOM files:
17 00 5c 10 4f 57 00 00 00 28 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

I get a lot of 00000 that never end.. Also the VR, Length etc structure is not correctly represented.. that kind of field is this and when do I know that it ends?

3) And for last.. whenever I have a group,element of (0096,0000) or (0044,0000) or (0042,0000) I have to skip the next 8 bytes cos they make no sense. For instance the VR is "þÿ" [hexa fe ff]... For instance:
40 00 75 02 53 51 00 00 96 00 00 00 fe ff 00 e0 8e 00 00 00 40 00 07 00 4c 4f

If you can help in ANY of this I'd be extremely grateful! Thank you!!

pedro.duarte.pt
Posts: 2
Joined: Mon May 27, 2013 2:50 pm

Re: DICOM bytewise doubts

Post by pedro.duarte.pt » Wed May 29, 2013 8:43 pm

Hey guys, anyone has any idea on any of these?
Or atleast just point me in the right direction I'll do the rest of the digging.

Seems like a straightforward thing for ppl developing DICOM parsers, I must be missing something obvious...

Aliraza47
Posts: 1
Joined: Wed Apr 15, 2015 1:21 pm

Re: DICOM bytewise doubts

Post by Aliraza47 » Wed Apr 15, 2015 2:03 pm

I will save last used calibration settings in next version. It will be in the end of this week.???

www.solitaire-champ.com
Last edited by Aliraza47 on Thu Dec 03, 2015 7:14 am, edited 2 times in total.

simeon
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Posts: 226
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Location: Bulgaria
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Re: DICOM bytewise doubts

Post by simeon » Sun Apr 19, 2015 10:25 am

Ali can you explain in more details about calibration settings?

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