[Elphel-support] jp4 compression software?

[Andrey Filippov]

You may also want to look at the JPEG header generation code -
http://elphel.cvs.sourceforge.net/viewvc/elphel/elphel353-8.0/os/linux-2.6-tag--devboard-R2_10-4/arch/cris/arch-v32/drivers/elphel/jpeghead.c?view=markup.
A small hack that uses color component numbers to communicate
additional
info (jp4 mode) to libjpeg.

Andrey

On Tue, Nov 17, 2009 at 7:24 AM, Andrey Filippov <elphel at gmail.com> wrote:

> There is also a small PHP demo linked from the LinuxDevices article (
> http://www.linuxfordevices.com/c/a/Linux-For-Devices-Articles/Elphel-camera-under-the-hood-from-Verilog-to-PHP/) -
> http://community.elphel.com/jp4/jp4demo.php . It explains JP4 and there is
> source code there too.
>
> Andrey
>
> On Tue, Nov 17, 2009 at 1:41 AM, Sebastian Pichelhofer <
> sebastian.pichelhofer at gmail.com> wrote:
>
>> JP4 rearranges same color pixels from the bayer pattern in 8x8 pixel
>> blocks to reduce high image frequencies that a pure bayer pattern would have
>> (better for JPEG compressor as JPEG basically reduces the most detailed
>> information = highest image frequency first).
>>
>> I am afraid there is no other code than the FPGA that shows how to create
>> JP4.
>>
>> Are you building a camera and want to compress the images in the camera?
>>
>> Regards Sebastian
>>
>> Jay Thompson wrote:
>>
>>> Hello,
>>>
>>> I've recently come across the Elphel project as I have been working on
>>> raw digital imagery / video workflows. I have a sequence of raw frames from
>>> a KAI-2093 that I would like to attempt to process with the Elphel's jp4 /
>>> avisynth workflow as well as experiment with a number of 'on the fly'
>>> demosaicers. I am wondering if there is a general implementation of the jp4
>>> compressor? I have seen the FPGA code but I cannot do anything with it.
>>>
>>> Thank you,
>>> jt
>>>
>>> _______________________________________________
>>> Support-list mailing list
>>> Support-list at support.elphel.com
>>>
>>> http://support.elphel.com/mailman/listinfo/support-list_support.elphel.com
>>>
>>
>>
>> _______________________________________________
>> Support-list mailing list
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>>
>
>
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