Is OpenJPEG support jpeg2000 with alpha?
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V.Abrutski
Sep 16, 2007, 2:03:29 PM9/16/07
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Is OpenJPEG support jpeg2000 with alpha?
V.Abrutski
Sep 27, 2007, 10:36:43 AM9/27/07
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Can somebody help me with this?
François-Olivier Devaux
Sep 27, 2007, 11:57:11 AM9/27/07
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Hi,
In short, the answer is no...
OpenJPEG does not read the content of the Channel Definition box (cdef box) inside the JP2 header, which specifies the meaning of the samples in each channel in the image.
However, you can always create a raw image with 4 components, and consider that the last component represents the transparency layer. After the decompression of this 4 component image, you should be able to reconstruct the image with the correct transparency information...
V.Abrutski a écrit :
In short, the answer is no...
OpenJPEG does not read the content of the Channel Definition box (cdef box) inside the JP2 header, which specifies the meaning of the samples in each channel in the image.
However, you can always create a raw image with 4 components, and consider that the last component represents the transparency layer. After the decompression of this 4 component image, you should be able to reconstruct the image with the correct transparency information...
V.Abrutski a écrit :
Callum Lerwick
Sep 27, 2007, 1:28:36 PM9/27/07
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On Thu, 2007-09-27 at 17:57 +0200, François-Olivier Devaux wrote:
> Hi,
>
> In short, the answer is no...
> OpenJPEG does not read the content of the Channel Definition box (cdef
> box) inside the JP2 header, which specifies the meaning of the samples
> in each channel in the image.
>
> However, you can always create a raw image with 4 components, and
> consider that the last component represents the transparency layer.
> After the decompression of this 4 component image, you should be able
> to reconstruct the image with the correct transparency information...
> Hi,
>
> In short, the answer is no...
> OpenJPEG does not read the content of the Channel Definition box (cdef
> box) inside the JP2 header, which specifies the meaning of the samples
> in each channel in the image.
>
> However, you can always create a raw image with 4 components, and
> consider that the last component represents the transparency layer.
> After the decompression of this 4 component image, you should be able
> to reconstruct the image with the correct transparency information...
Hmmm, Second Life is using alpha channels. And it is interoperating with
KDU. I presume the second thing must be what its doing. :)
Galfar
Nov 17, 2007, 9:00:55 AM11/17/07
to OpenJPEG
Hi,
I've been using the "create a raw image with 4 components, and
applications that use OpenJPEG and it works well but most other image
viewers/editors
(Photoshop, PSP, XnView, ...) refuse to load these 4 channel jp2
without the cdef box in them.
Are there any plans on adding cdef reading/writing to OpenJPEG in the
future?
On Sep 27, 4:57 pm, François-Olivier Devaux
I've been using the "create a raw image with 4 components, and
consider that the last component represents the transparency layer"
method in my
applications that use OpenJPEG and it works well but most other image
viewers/editors
(Photoshop, PSP, XnView, ...) refuse to load these 4 channel jp2
without the cdef box in them.
Are there any plans on adding cdef reading/writing to OpenJPEG in the
future?
On Sep 27, 4:57 pm, François-Olivier Devaux
François-Olivier Devaux
Dec 10, 2007, 8:17:04 AM12/10/07
to open...@googlegroups.com
Hi,
Unfortunately, this is not planned in the near future... but contributions are welcome !
François
Galfar a écrit :
Unfortunately, this is not planned in the near future... but contributions are welcome !
François
Galfar a écrit :
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