[Dcmlib] Re: openjpeg and 16bits j2k image

[Antonin Descampe]

[Hervé, I cc you to let you know an initiative from the gdcm team  
integrating OpenJPEG in their project]

Hi,

What a nice (and fast) job ! Happy to know OpenJPEG integrated in your  
project. Thanks Mathieu for the patches, I will apply them asap but it  
would be indeed more convenient with one single "big" patch (as you  
proposed it in one of your mails).

> Where can we get *your* version of open jpeg?

Jean-Pierre, I assume you get the correct version now as Mathieu has  
uploaded OpenJPEG on your cvs. If not, just tell me and I will send you  
the files (I've still problems to commit changes on our cvs, I hope  
this will be fixed soon).

I would like to mention also an initiative from Hervé Drolon (FreeImage  
Team Project Leader, cc in this mail) working on OpenJPEG to make it  
multithread-safe. One of the big issue concerning the actual version  
(on the cvs) is indeed that it does not work with multi-threads.

Hervé, I received your OpenJPEG snapshot, thanks a lot for all your  
work, it's very impressive ! It will just take me some time to upload  
your contributions on the cvs as some changes have (unfortunately) been  
made in comparison with the version you used.

Best regards,

Antonin

> Merging done !
>
> Antonin, feel free to comment on
> http://www.creatis.insa-lyon.fr/viewcvs/viewcvs.cgi/gdcm/src/ 
> gdcmopenjpeg/
>
> I have added the BSD license, there is a reference to the online one  
> in the small README I added:
> http://www.creatis.insa-lyon.fr/viewcvs/viewcvs.cgi/gdcm/src/ 
> gdcmopenjpeg/README.gdcm.txt
>
>
> Mathieu
>
> Antonin Descampe wrote:
>> Hi Mathieu,
>> Well I'm happy having helped you a bit and also that you will  
>> integrate  openjpeg in gdcm. As we are only two people maintaining  
>> the library and  as it is certainly not our main occupation (still a  
>> thesis to  finish...), I cannot promise you to answer your potential  
>> future  requests very fast... But feel free to change the things you  
>> want in  the library and I will do my best to help you again if  
>> needed.
>> cheers,
>> antonin
>> Le 24-oct.-05, à 15:54, Mathieu Malaterre a écrit :
>>> Ride on, dude !
>>> This is an excellent job, I am very excited. So now that I know you   
>>> are very serious, I will definitely integrate openjpeg into gdcm.
>>>
>>> We'll keep in touch for the cmake'ification of the project.
>>> Mathieu
>>> Result is here:
>>> http://www.creatis.insa-lyon.fr/~malaterre/jpeg2000/  
>>> CT_Phillips_JPEG2K_Decompr_Problem-antonin.png
>>>
>>> Antonin Descampe wrote:
>>>
>>>> Salut Mathieu,
>>>> Voilà j'ai fait les modifications nécessaires pour décoder   
>>>> correctement tes images. Il y a encore une ou deux différences avec  
>>>>  kakadu, certains pixels sont noirs alors qu'ils devraient être   
>>>> blancs. Sans doute un problème d'overflow en logique signée... Je   
>>>> vais essayer de résoudre ce problème.
>>>> Je ne parviens pas à faire de commit ce matin sur le cvs donc je   
>>>> t'envoie les fichiers modifiés dans ce mail, en attendant de  
>>>> pouvoir  uploader les modifs sur le cvs.
>>>> A+,
>>>> Antonin
>>>> Le 18-oct.-05, à 15:28, Mathieu Malaterre a écrit :
>>>>
>>>>> Salut Antonin,
>>>>>
>>>>>     Pas de nouvelle sur mon probleme ?
>>>>>     Sinon est-ce qu'il y a un moyen d'avoir openjpeg CVS en ligne  
>>>>> de  commande ?
>>>>>
>>>>> Merci
>>>>> Mathieu
>>>>>
>>>>>>>
>>>>>>> Salut,
>>>>>>>
>>>>>>> J'ai répondu à ton post
>>>>>>> http://www.openjpeg.org/forum/viewtopic.php?t=18
>>>>>>>
>>>>>>> Il s'agit d'un problème de requantification. Lorsqu'on multiplie  
>>>>>>>  le coefficient par le pas de quantification juste avant l'IDWT,  
>>>>>>>  une perte de précision peut avoir lieu car on utilise que des   
>>>>>>> entiers (4 bytes). Cela devrait pouvoir se résoudre en utilisant  
>>>>>>>  des double pour cette opération-là puis en repassant en entiers  
>>>>>>>  juste après. Je tâche de m'en occuper assez vite.
>>>>>>>
>>>>>>> A+,
>>>>>>>
>>>>>>> Antonin
>>>>>>>
>>>>>>> Le 08-oct.-05, à 20:09, Mathieu Malaterre a écrit :
>>>>>>>
>>>>>>>> Salut,
>>>>>>>>
>>>>>>>>     Est-ce que quelqu'un lit le forum ? Je voulais savoir si le  
>>>>>>>>  probleme que je rapporte etait un probleme connu. Et si une   
>>>>>>>> solution existait.
>>>>>>>>
>>>>>>>> Merci
>>>>>>>> Mathieu
>>>>>>>>
>>>>>>>> [openjpeg and 16bits j2k image]
>>>>>>>> http://www.openjpeg.org/forum/viewtopic.php?t=18
>>



--
Antonin Descampe - PhD student

  descampe at tele.ucl.ac.be
  Communications and Remote Sensing Lab
  Université catholique de Louvain, Belgium
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