Which free software could acquire 48 bits color depth pictures from a scanner ?

Hi all,

I need to scan some old films using a 48 bits color depth (in order to keep
the quality after some graphical process).
My Canon CS5200F does it well but none of my graphical softwares can handle
48 bits picture.

The GIMP 2.6.2 translated my pictures from 48 to 24 bits.
IrfanView does the same as the GIMP (48 => 24).
I also tried XnView which is supposed to handle 48 bits pictures but when
the picture is transfered from the scanner, I get a black screen (I tried
in 24 bits and got the correct picture so this is really a color depth
problem).

I heard that the GIMP 2.6.2 was using a module called GECL which handles 48
bits pictures but I did not find any to configure/activate it : my pictures
are always handled as 24 bits picture.

I do not want to buy any graphical software because many free ones exist.

=> Do you know any free software or plugin which could work with 48 bits
pictures acquired from a scanner ?

Thanks in advance for your help.

 

try the 30 day free trial of adobe photoshop cs4.

 

While not free, it's relatively inexpensive. Photoline www.photoline.com From
what I recall the free demo doesn't really expire nor cripple itself, you just
get a longer nag screen after 30 days.

If you save your scans in CMYK format then it will even properly handle 64-bit
color-depths. It's the only software that I know of that can do this. PhotoShop
still only uses 16-bit math for most of its tools and functions. Wholly
incapable of retaining all that extra data during any processing of these larger
bit-depths. This has been a thorn in the side of the "pro" world for the last 2
decades of using PhotoShop, but they all seem to ignore it and live with it.
Only recently has Adobe started to add in some 32-bit math routines to only some
of their tools and features, but by no means do all PhotoShop tools and filters
use 32-bit math. They're still working on it. Photoline has been a fully 32-bit
math platform for the last 15 years.

 

Sorry, wrong link.

Photoline is at www.pl32.net

While not free, it's relatively inexpensive. Photoline www.photoline.com From
what I recall the free demo doesn't really expire nor cripple itself, you just
get a longer nag screen after 30 days.

If you save your scans in CMYK format then it will even properly handle 64-bit
color-depths. It's the only software that I know of that can do this. PhotoShop
still only uses 16-bit math for most of its tools and functions. Wholly
incapable of retaining all that extra data during any processing of these larger
bit-depths. This has been a thorn in the side of the "pro" world for the last 2
decades of using PhotoShop, but they all seem to ignore it and live with it.
Only recently has Adobe started to add in some 32-bit math routines to only some
of their tools and features, but by no means do all PhotoShop tools and filters
use 32-bit math. They're still working on it. Photoline has been a fully 32-bit
math platform for the last 15 years.

 

actually they're raving about cs4 being *64 bit*.

 

it doesn't. photoshop uses 32 bit math internally (or 64 bit in cs4)
when making calculations on an 8 bit per channel image.

 

basically, speed.

 

Too many people with too little understanding.

32-bit pixels is different from being able to handle a 64-bit address
space. Whining that PS cn't do 32-bit pixels for all functions is
silly given that there's no output device that can handle even a
16-bit range.

 

16 bit printing is supported on cs4/mac.

 

It's not free but Photo Paint will handle 48 bit RGB.



Eric Stevens

 

While all operating systems can load and view 32 and 64 bit color-depths
(usually by averaging to lower bit-depths if your display and software can't
handle it), that is where it ends. The moment you use an editor with only 16-bit
math you are starting to truncate valuable data during each process due to
rounding errors. Most will never notice it due to the limitations of their
display, but this loss does exist. This is why they put up with it in PhotoShop
for so long, what you can't see won't hurt you. For those that paid dearly to
get every bit-depth in their images they would like to have all that information
retained.

Let's say for example that you only have a 4-bit depth math package. 4-bit
floating-point math means that only FOUR significant binary characters can be
used to do the math. Any operation done on any color values will be truncated by
averaging mathematically. A decimal (not binary) example: If you have an RGB
pixel's red value of 38756 on a 16-bit color depth (values of 0 to 65535), and
you want to reduce that by 33%, you end up with a value of 12789.48. In a 4-bit
math platform that is rounded to 12790.00 Only 4-significant digits may be used,
the 89.48 is rounded to a value of 90. (Keeping in mind that in a 4-bit math
depth which is all performed in binary, using values 0-7, so the significant
digits in decimal (values 0-9) as presented here for examples, becomes much less
than this, even greater rounding is done sooner. This is only provided as a
quick example of what happens.) As more editing operations are performed those
approximated color values will carry over their errors and be duplicated. Each
time an operation is performed on that data then more math errors will be
introduced, always being rounded-off (lost) in the math functions. This is why
it's a good rule-of-thumb to always use at least the same or higher
floating-point math depth as your image color-depth. Perform 2 or more
operations on any set of pixels with a lower bit-depth math platform and you may
have drastically changed your color values by the time you are done. This is
precisely why PhotoShop could never incorporate the more advanced Lanczos-8
resampling algorithms. Its math platform was/is just incapable of doing the
calculations necessary to retain the image details during rotations and
resizings. The best that PhotoShop could ever offer was (and is) simplistic
bicubic interpolations, always resulting in muddy images and soft edges due to
lost details every time those operations are performed.

32-bit math has been around since Windows 3.1 if you installed the System32 math
package, and more commonly found in the very first versions of Windows 95, the
very first version of Win95 happening in 1993 (if you were one of the alpha
testers for MS, as I was). Windows 3.1 was primarily 16-bit math but allowed you
to use 32-bit software if your CPU allowed for it and if you installed some
accessory files (the origin of the "system32" Windows folder, there used to be
just a "system" folder in Win3.1). Photoline, originally called Photoline32,
recently renamed to just Photoline, was named that just because it was the ONLY
graphic editor that fully supported the new 32-bit math platform that started
during the Windows 3.1 to Window 95 bridge years.

A slight error, checking online I see now that Photoline32 was released in 1995.
I only know I was using it on the very first versions of Windows 95 when Win95
was released to the public (as the Windows-95 beta version due to a marketing
lawsuit that Gates didn't want to deal with, in-house memos that I was privy
to). The 2 year discrepancy about Photoline due to my alpha-testing phase of
Windows 95 which started in 1993. I only recall that I latched onto Photoline as
soon as I discovered its existence. It's been the backbone of my graphic editing
platform all these years due to how much more it can do and how much more
accurately it can do it. If someone hands me a complimentary copy of Photoshop,
I merely thank them, then after they have left I throw it in the waste-basket,
where it's always belonged. I wouldn't dare even give it to a friend, I wouldn't
want them to have to put up with that Adobe nonsense.

 

32 bit math was available *long* before that.

so ebay it to a stranger.

 

I believe we are discussing desktop computers and home ran operating systems.
Not early mainframes that have nothing to do with the topic. "The topic" which
you so quickly try to avoid at every turn. Trolls are like that. That's all they
can bring to a discussion, to get that attention that they so desperately crave,
from anyone or anything possible.

I have more respect than that for someone I don't know. But to you? I'd sell it
to you in a heartbeat for $1 less than the going rate.

 

mainframes certainly did, but if you want to restrict it to desktop
computers, that's fine too. the macintosh was a 32 bit machine since
its introduction in january 1984 and photoshop debuted on the mac in
1990, appearing on windows a couple of years later with 32 bit math
internally on both platforms.

and cpu bus width isn't the determining factor either. even on an 8
bit computer, one can do higher precision math, it just takes more
instructions.

 

I wasn't aware that the 80386 (introduced 1985, produced in significant
numbers from 1986) )was used in mainframes instead of in desktop
computer.
Windows 3.1 came in 1992, which at least to me is 6 years _AFTER_ the
introduction of 32-bit math.

jue

 

Non sequitur. I referred to devices, not support for drivers.

 

And that is the point being made. Trying to use software which only has 16-bit
math as the majority of it's functions (i.e. Photoshop) on 48-bit or 64-bit
color-depth data, is like going back to 1984.

 

Except that PS has 8, 16, or 32-bit math PER CHANNEL on its images.
Understand the difference? Three channels times 16 bits per channel
is 48 bits. Of course, these programs support many more than just
three channels, which is why you seldom see "48-bit color".

 

that's actually the machine i was thinking of. was it a cyber 175? 60
bit words were fun.

 

no matter how often you say it, it's still wrong.