Scanners and 48 bit data

Most scanners claim to provide 48 bit data. What application software
can use 48 bit data? PS, PSP, ??

Does the Twain standard import 48 bit data from scanner to application?

If I want to save the image before I am finished editing it, what file
formats retain 48 bit color depth?

Both Photoshop and Photoshop Elements 3 will work in 48 bit mode and
yes you can get the file through the twain interface.

For saving the file in 48 bit more I use the native file for Photoshop,
psd files, you can also save in a number of other formats including jpg
2000 and tiff.

Scott

Don Stauffer in Minneapolis wrote:
Most scanners claim to provide 48 bit data. What application software
can use 48 bit data? PS, PSP, ??

Does the Twain standard import 48 bit data from scanner to application?

If I want to save the image before I am finished editing it, what file
formats retain 48 bit color depth?


Photoshop certainly can use and manipulate 48 bit
image files. ACDSee can usually view them (but
sometimes chokes on very big ones.)

..PSD and .TIF formats can be used to save these files.

I don't know much about TWAIN anymore. In Windoze
it's been superceded by WIA, but in any case I find
myself using standalone apps, both for my scanners
and my digicams.


rafe b.
http://www.terrapinphoto.com

Scott W commented courteously ...

Both Photoshop and Photoshop Elements 3 will work in
48 bit mode and yes you can get the file through the
twain interface.

For saving the file in 48 bit more I use the native
file for Photoshop, psd files, you can also save in
a number of other formats including jpg 2000 and tiff.

Scott, being a PSP 9 user with no knowledge of PS at all,
does PS and PSE really do everything in 48 bit?

48-bit color comes up fairly often these days in a variety
of NGs. Again, being ignorant of 48-bit color, I always
ask people "can you tell the difference vs. 24-bit?" and
"on what do you display it or print it?".

Not to mention, I have to ask "what original could
possibly be scanned with a 48-bit scanner that actually
has that many colors?"

Last I looked, Windoze was 32-bit, and the extra 8 bits
are for transparency, rather than additional colors.

--
ATM, aka Jerry

All Things Mopar wrote:
Scott W commented courteously ...

Both Photoshop and Photoshop Elements 3 will work in
48 bit mode and yes you can get the file through the
twain interface.

For saving the file in 48 bit more I use the native
file for Photoshop, psd files, you can also save in
a number of other formats including jpg 2000 and tiff.

Scott, being a PSP 9 user with no knowledge of PS at all,
does PS and PSE really do everything in 48 bit?

48-bit color comes up fairly often these days in a variety
of NGs. Again, being ignorant of 48-bit color, I always
ask people "can you tell the difference vs. 24-bit?" and
"on what do you display it or print it?".

Not to mention, I have to ask "what original could
possibly be scanned with a 48-bit scanner that actually
has that many colors?"

Last I looked, Windoze was 32-bit, and the extra 8 bits
are for transparency, rather than additional colors.

--
ATM, aka Jerry
I don't know about PS but PSE 3 will do a lot in 48 bit mode but not
all. It is handy to work in 48 bit mode as you have more dynamic range
and you can do repeaded adjustments to the levels with out degreading
the image, once you convert to a 24 bit bitmap you can't tell the
differnace.

Scott

In article ,
All Things Mopar wrote:

48-bit color comes up fairly often these days in a variety
of NGs. Again, being ignorant of 48-bit color, I always
ask people "can you tell the difference vs. 24-bit?" and
"on what do you display it or print it?".

I think, you may be asking the wrong question. The real use for 48 bit
colour is to avoid quantisation problems (clipping and rounding) which occur
due to image processing and the use of wide-gamut colourspaces (e.g.
Adobe-RGB). For final presentation, 24bpp is perfectly adequate, but 48bpp
is useful as a working format to avoid image degredation.

"What application softwre can use 48 bit data?" The ones I know about are

PhotoShop CS

PhotoShop Elements 3 (limited)

Picture Window Pro

Corel PhotoPaint

CinePaint (customized version of "The GIMP" ...
but it's pretty much a "rolling alpha release" at this point)

"If I want to save the image before I am finished editing it, what file
formats retain 48 bit color depth?" The ones I know about are


PhotoShop (PSD)

TIFF

*Probably* Corel PhotoPaint's proprietary format




"Don Stauffer in Minneapolis" wrote in message
...
Most scanners claim to provide 48 bit data. What application software
can use 48 bit data? PS, PSP, ??

Does the Twain standard import 48 bit data from scanner to application?

If I want to save the image before I am finished editing it, what file
formats retain 48 bit color depth?

Scott W commented courteously ...

I don't know about PS but PSE 3 will do a lot in 48
bit mode but not all. It is handy to work in 48 bit
mode as you have more dynamic range and you can do
repeaded adjustments to the levels with out degreading
the image, once you convert to a 24 bit bitmap you
can't tell the differnace.

Thanks, Scott.

So, you're working on the histogram and other aspects of
the image that can benefit from the additional bit width?

I hang out on a couple PSP news groups, where 48-bit color
comes up often. Natually, the Corel crowd pooh-poohs this,
but I'm sure they are working on it.

However, some of the very creative photographers and
digital artists always ask "where's the beef?". One or 2
steadfastly maintain that nearly all of the extra 48 bits
is just noise at each end of the histogram.

Natually, I don't know, since I don't have a camera or a
scanner which will go beyond 24-bit. And, if you've seen
any of my posts, my requirements as well as my PSP 9
expertise, is a long ways below where I'd see any
advantage to 48-bit. But, I'm trying to stay on top of the
growing trend in the industry so I am ready for it when it
becomes of interest to me.


Scott





--
ATM, aka Jerry

Chris Brown commented courteously ...

I think, you may be asking the wrong question.

I probably am asking the wrong question, Chris, as I don't
understand enough about this nor have any hardware that I
can use to test my "theories".

The real use for 48 bit colour is to avoid
quantisation problems (clipping and rounding)
which occur due to image processing and the use of
wide-gamut colourspaces (e.g. Adobe-RGB).

I understand Adobe RGB vs. the "standard" sRGB color
space, but not very well. Are you doing your image
processing on RAW images, I assume?

For final presentation, 24bpp is perfectly adequate,
but 48bpp is useful as a working format to avoid image
degredation.

I'm aware from talking to friends in Chrysler's Photo
Imaging department that there *are* things you can "see
with 32-bit or 48-bit color, I've been shown examples of
banding and posterization in 24-bit that go away with high
width. But, these guys have hundreds of thousands of
dollars invested in computer hardware, cameras, printers,
and color calibration software/hardware.

With that bloviating preface, could you continue my
education and explain briefly what you mean by "avoiding
image degradation"?

Thanks, Chris.

--
ATM, aka Jerry

All Things Mopar wrote:
[]
Natually, I don't know, since I don't have a camera or a
scanner which will go beyond 24-bit. And, if you've seen
any of my posts, my requirements as well as my PSP 9
expertise, is a long ways below where I'd see any
advantage to 48-bit. But, I'm trying to stay on top of the
growing trend in the industry so I am ready for it when it
becomes of interest to me.

Actually, you have a Nikon 5700 which shoots in RAW mode if you wish. I
understand that in that mode you get 12 bits per colour, so you can
already generate 36-bit images. The 12-bit data is a linear value, the
8-bit JPEG data nearer a log or gamma-corrected value, so the available
dynamic range is similar in each, but the accuracy of representation in
the 8-bit data isn't as high as in the 12-bit data. {But does that
matter?]

Broadly speaking, it's one of those awkward choices - 8 bits per colour is
fine if everything is 100% exposed correctly and the dynamic range of the
scene isn't too large. Having the 12-bit data gives you a little more
margin. But computers work better with either 8-bit or 16-bit colours
rather than 12-bit, so your choice is between 24-bit RGB and 48-bit RGB.
By the way, there are those who argue that PhotoShop only works with
15-bit colour data, not 16-bit data. Whatever, the lower few bits are
just noise.

Cheers,
David