Old NEMA compression?

Bonjour to all,

I just run across images from Siemens, apparently in SPI, but that
have the following tags:

(0008,0010) (Retired) Recognition Code ACRNEMA 20
....
(0008,0040) (Retired) Data Set Type 0
(0008,0041) (Retired) Data Set Subtype IMA SPI
....
(0028,0050) (Retired) Manipulated Image (no data)
(0028,005f) (Retired) Compression Recognition Code ACR/NEMA 1.0
(0028,0060) (Retired) Compression Code DEF
(0028,0062) (Retired) Compression Label SIENET 1.0
(0028,0065) (Retired) Compression Sequence DPCM\CODE
(0028,0066) (Retired) Compression Step Pointers (0028,0080) /
(0028,0800)
(0028,0080) (Retired) Predictor Rows 2
(0028,0081) (Retired) Predictor Columns 3
(0028,0082) (Retired) Predictor Constants 65535 / 1 / 0 / 1
/ 0 / 0
....
(0028,0800) (Retired) Code Label LEMPEL_ZIV
(0028,0802) (Retired) Number of Table 0
(0028,0804) (Retired) Bits For Code Word 16

The data is (as expected) compressed and placed in groups 7F0x (as in
other SPI compressions) .

Now, since all these compression tags have be retired, one has to
assume that at some point they where documented?

Is there any information I can find on the compression used here, or
do I have to reverse engineer it? (a DPCM compression should be
doable, but if the information already exist, why re-invent the
wheel?)

If you have anything, thanks in advance.

Yves

Yves Martel wrote:
[color=blue]
> The data is (as expected) compressed and placed in groups 7F0x (as in
> other SPI compressions) .
> Now, since all these compression tags have be retired, one has to
> assume that at some point they where documented?[/color]

The ACR/NEMA compression supplement is available from
[url]ftp://medical.nema.org/MEDICAL/Dicom/1989/PS2_1989.pdf[/url]

Regards,
Marco Eichelberg

On Oct 23, 4:01*pm, Marco Eichelberg <eichelberg_nos...@offis.de>
wrote:[color=blue]
> Yves Martel wrote:[color=green]
> > The data is (as expected) compressed and placed in groups 7F0x (as in
> > other SPI compressions) .
> > Now, since all these compression tags have be retired, one has to
> > assume that at some point they where documented?[/color]
>
> The ACR/NEMA compression supplement is available fromftp://medical.nema.org/MEDICAL/Dicom/1989/PS2_1989.pdf
>
> Regards,
> Marco Eichelberg[/color]

Yves,

Don't forget to read this post too:

[url]http://groups.google.fr/group/comp.protocols.dicom/browse_thread/thread/2c46923a89fc0bdb[/url]

I think you'll find some help in D. Clunie tools (I admit I was not
able to get anything out of the files though)

2cts

On Thu, 23 Oct 2008 08:58:58 -0700 (PDT), Mathieu Malaterre
<mathieu.malaterre@gmail.com> wrote:
[color=blue]
>On Oct 23, 4:01*pm, Marco Eichelberg <eichelberg_nos...@offis.de>
>wrote:[color=green]
>> Yves Martel wrote:[color=darkred]
>> > The data is (as expected) compressed and placed in groups 7F0x (as in
>> > other SPI compressions) .
>> > Now, since all these compression tags have be retired, one has to
>> > assume that at some point they where documented?[/color]
>>
>> The ACR/NEMA compression supplement is available fromftp://medical.nema.org/MEDICAL/Dicom/1989/PS2_1989.pdf
>>
>> Regards,
>> Marco Eichelberg[/color]
>
>Yves,
>
> Don't forget to read this post too:
>
>[url]http://groups.google.fr/group/comp.protocols.dicom/browse_thread/thread/2c46923a89fc0bdb[/url]
>
> I think you'll find some help in D. Clunie tools (I admit I was not
>able to get anything out of the files though)
>
>2cts[/color]

Thanks Marco and Merci Mathieu :)

That was exactly what I needed!

Though you seem to mention that David's tool support the old NEMA
compression? I must admut I didn't find any referenec to that in his
code (but I didn't search that much...). Do you support it David?

Anyway, I have now added the support for the SIENET Lempel-Ziv images
to my programs.

However, I noticed from the doc that a LOT of compressions are
possible.

Up to now, I have seen "HUFFMAN" from Siemens CT, and "LEMPEL-ZIV"
from SIENET stations, but does anybody have sample images using the
old NEMA compression that is not one of these?

Yves

On Oct 27, 2:53 pm, Yves Martel <Martel(at)TomoVision.com> wrote:[color=blue]
> On Thu, 23 Oct 2008 08:58:58 -0700 (PDT), Mathieu Malaterre
>
>
>
> <mathieu.malate...@gmail.com> wrote:[color=green]
> >On Oct 23, 4:01 pm, Marco Eichelberg <eichelberg_nos...@offis.de>
> >wrote:[color=darkred]
> >> Yves Martel wrote:
> >> > The data is (as expected) compressed and placed in groups 7F0x (as in
> >> > other SPI compressions) .
> >> > Now, since all these compression tags have be retired, one has to
> >> > assume that at some point they where documented?[/color][/color]
>[color=green][color=darkred]
> >> The ACR/NEMA compression supplement is available fromftp://medical.nema.org/MEDICAL/Dicom/1989/PS2_1989.pdf[/color][/color]
>[color=green][color=darkred]
> >> Regards,
> >> Marco Eichelberg[/color][/color]
>[color=green]
> >Yves,[/color]
>[color=green]
> > Don't forget to read this post too:[/color]
>[color=green]
> >[url]http://groups.google.fr/group/comp.protocols.dicom/browse_thread/thre[/url]...[/color]
>[color=green]
> > I think you'll find some help in D. Clunie tools (I admit I was not
> >able to get anything out of the files though)[/color]
>[color=green]
> >2cts[/color]
>
> Thanks Marco and Merci Mathieu :)
>
> That was exactly what I needed!
>
> Though you seem to mention that David's tool support the old NEMA
> compression? I must admut I didn't find any referenec to that in his
> code (but I didn't search that much...). Do you support it David?[/color]

As said in my post, the only place referencing the Variable Pixel Date
was in:

../appsrc/dcfile/dcdecmpr.cc

I do not know more than that.
[color=blue]
> Anyway, I have now added the support for the SIENET Lempel-Ziv images
> to my programs.[/color]

Congrats !
BTW Your public dict is missing attribute "0020,31xx"

-Mathieu