Help with compression research (Need sample images)

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Sachin Garg - 26 Jan 2007 07:30 GMT

Hi,

I am a computer science researcher working on image compression
algorithms and need some large, high quality images to help with my
research.

Most of the images available online are JPEG'ed, but I need images
which were captured digitally and then saved without any loss, maybe as
RAW. (I checked the digital cameras with all my friends, but ouch! none
of them had raw saving options, only jpeg :-(

Data compression researchers have some famous (at least among us
researchers) image sets which were released by Kodak, Jpeg committee,
and some universities over the years but they are all very old to be
used for research now. For example, they are mostly 512x512 images
with 8-bit depth. Most modern cameras can capture *much* more detail
than this, and at 12 or even 16 bits per color.

I need around 50 RAW images taken from a wide-range of digital cameras,
saved as RAW with full quality, without any loss or editing. If some of
you can pool in a few images each, I will have the set ready :-)

I can't think of any way other than this to get around 50 full-quality
snaps from 10-20 'expensive' cameras.

(I guess most of you are professional or enthusiast photographers, and
each snap you have taken must be a piece of art for you. I don't need
any of your prized photographs, just about any good snaps will do.)

Thanks in anticipation.

Sachin Garg [India]
www.sachingarg.com | www.c10n.info

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Just D - 26 Jan 2007 07:41 GMT

You're happy because you're using gmail.com, it's 2-3 GBytes of email space
now, but anyway it's looking like committing a suicide if at least a few
people send you their images say 10 each one to your mail account then you
will be very happy downloading all them serialized into base64 (the mail
size will be increased say at ~30-50% because of attachment serialization)
or something...))) Although 50 RAW, 10 mpx each, times number of people
wanting to help you... pretty enough amount of info...)

Let me know if you get nothing in a few days to let me send my part if
pictures...) I guess content is not so important to avoid sending you some
unique shots? You just need a set of different pictures to play with them,
correct? And you can read RAW from your app. Btw, what about compressed RAW
producing by Nikon D80, can you read them? Have a source code? Can post it
to me? :)

Just D.

> Hi,
>
[quoted text clipped - 29 lines]
> Sachin Garg [India]
> www.sachingarg.com | www.c10n.info

Reply to this Message

Sachin Garg - 26 Jan 2007 08:03 GMT

> You're happy because you're using gmail.com, it's 2-3 GBytes of email space
> now, but anyway it's looking like committing a suicide if at least a few
[quoted text clipped - 3 lines]
> or something...))) Although 50 RAW, 10 mpx each, times number of people
> wanting to help you... pretty enough amount of info...)

I guess I will try to setup an upload facility at my homepage, till
then you guys can try emailing stuff. I hope gmail will handle it.

> Let me know if you get nothing in a few days to let me send my part if
> pictures...) I guess content is not so important to avoid sending you some
> unique shots? You just need a set of different pictures to play with them,
> correct?

Right, I don't need anything special. Just a bunch of images from
different cameras, saved without loss.

> And you can read RAW from your app. Btw, what about compressed RAW
> producing by Nikon D80, can you read them? Have a source code? Can post it
> to me? :)

For proprietary RAW formats, I can maybe use Adobe's RAW-to-DNG
converter. Then I can handle DNG using opensource libtiff or just open
it in Photoshop to save it in some other basic format, like maybe PPM.

But am not very experienced with camera raw formats so if I face any
trouble, I can always come back to this forum :-)

> Just D.
>
[quoted text clipped - 31 lines]
> > Sachin Garg [India]
> >www.sachingarg.com|www.c10n.info

Reply to this Message

Barry Pearson - 26 Jan 2007 08:49 GMT

[snip]

> I need around 50 RAW images taken from a wide-range of digital cameras,
> saved as RAW with full quality, without any loss or editing. If some of
> you can pool in a few images each, I will have the set ready :-)
>
> I can't think of any way other than this to get around 50 full-quality
> snaps from 10-20 'expensive' cameras.

[snip]

Here are some sources:
http://www.dimagemaker.com/specials/cameras/camtests.php
http://www.glasslantern.com/RAWpository/
http://digikam3rdparty.free.fr/TEST_IMAGES/RAW/HORIZONTAL/

Signature

Barry Pearson
http://www.barrypearson.co.uk/photography/

Reply to this Message

Sachin Garg - 26 Jan 2007 11:02 GMT

On Jan 26, 1:49 pm, "Barry Pearson" <n...@childsupportanalysis.co.uk>
wrote:

> [snip]
> I need around 50 RAW images taken from a wide-range of digital cameras,
[quoted text clipped - 14 lines]
> Barry Pearson
> http://www.barrypearson.co.uk/photography/

This looks like exactly what I was looking for. Thanks a lot :-)

While this solves my requirements, any more pointers/contributions are
still welcome.

Thanks again,

Sachin Garg [India]
www.sachingarg.com | www.c10n.info

Reply to this Message

Paul Repacholi - 29 Jan 2007 14:23 GMT

> While this solves my requirements, any more pointers/contributions are
> still welcome.

Go to the Space Telescope archive, and find the FOC images sets of SN1987A,
4044 I think, but check. Down load them and have fun. They are the most
compression hostile images I've ever come across!

Reply to this Message

Sachin Garg - 29 Jan 2007 17:39 GMT

> "SachinGarg" <schn...@gmail.com> writes:
> > While this solves my requirements, any more pointers/contributions are
[quoted text clipped - 3 lines]
> 4044 I think, but check. Down load them and have fun. They are the most
> compression hostile images I've ever come across!

Hmmm, that will be interesting. While my immediate interest was to
focus on usual photographs, it won't hurt to see if there is a
breakthrough waiting to happen there ;-)

Or it will atleast help as as worst-case analysis.

Thanks

Sachin Garg [India]
www.sachingarg.com | www.c10n.info

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Sachin Garg - 31 Jan 2007 09:48 GMT

I tried looking for this but lost my way big time :-)

Can you please guide me where exactly to go?

Sachin Garg [India]
www.sachingarg.com | www.c10n.info

Reply to this Message

Paul Repacholi - 31 Jan 2007 13:43 GMT

>> "SachinGarg" <schn...@gmail.com> writes:
>> > While this solves my requirements, any more pointers/contributions are
[quoted text clipped - 7 lines]
>
> Can you please guide me where exactly to go?

Not anymore! e-mail the help address for the archive. You want the
pre-costar set of SN1987A from the Faint Object Camera.

I think the data set ID is 4044, but don't bet on it.

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