What was wrong with film?

Recently, Gregory W Blank posted:
"Neil Gould" wrote:

The salient questions are, what comprises "enough data" and what
degree of probablity is acceptable? Without the ability to evaluate
the content of an image, no amount of analysis will be able to
reliably identify an original digital image from an altered digital
image.

As John stated above 50% more like 70% preferred

Sorry... 50% is all that is guaranteed! ;-)

If this really became a legal, issue I would guess the source of
the image generation could be analyzed to determine
if the origin was compromised.

Just how would this be accomplished?
Neil

My thought is the pixel alignment of an original scan or capture
will fall into a mathimatic sequence, according to the device used
to create the image, any deviance from the device signature would
imply manipulation. I could be wrong its really just idle speculation
from my stand point. I would also guess that even as a file is saved
that there is some root signature left by such changes as file
converstion and or manipulation, even if that signature is only to be
found on the hard drive it was created on.

I'm not sure what you mean by "pixel alignment" or "mathimatic (sic)
sequence", as pixels have only sequential loci in a matrix, and lack
physical properties such as dimension. All that exists is a locus and a
set of color values.

A device signature could be established, given the imperfections of any
physical device. However, to know whether the image was altered, you'd
have to have access to the original device *and* the original image. Not
only is that impractical, but it's still no guarantee. Even those without
access to the original device could emulate its imperfections without much
difficulty, and within enough accuracy that a positive determination that
the image was altered would be difficult, if not impossible. Those with
access to the original device could fake an image, complete with accurate
imperfections quite easily.

Neil

David J. Littleboy writes:

If that's what they want, how is that a problemg?

It's not, unless you are trying to use such people as an argument to
support the assertion that digital is taking over from film.

--
Transpose hotmail and mxsmanic in my e-mail address to reach me directly.

Gregory W Blank writes:

First one defines the expert. One realizes the possiblity
that computers can recognize the manipulation of pixels non native
in two composited or otherwise altered data files.

Not any more so than human beings.

--
Transpose hotmail and mxsmanic in my e-mail address to reach me directly.

Gregory W Blank writes:

So for discussions sake, you don't believe given enough data
a computer can give a probability assessment as to whether
the image is real or fake?

No more so than a human being; after all, the computer programs are
written by human beings.

If this really became a legal, issue I would guess the source of
the image generation could be analyzed to determine
if the origin was compromised.

In reality, there's a simpler way: You have the photographer testify in
court that the images shown in court were indeed the images he took.

--
Transpose hotmail and mxsmanic in my e-mail address to reach me directly.

Dennis O'Connor writes:

She 'was' young... All she had to do was have him watch a demo as she has
her photographer/buddy somewhere else in the country take a photo of
something, as directed over the phone by ye curmudgeon, then dump it onto
the phone line and load it into her laptop in front of ye curmudgeon, ready
to be sent to the composing desk, a minute from the taking... That he would
have instantly understood...

.... that it's extremely difficult to get a workflow like that to
actually work in the field.

--
Transpose hotmail and mxsmanic in my e-mail address to reach me directly.

Reciprocity Failure writes:

Anyone who has ever worked in a camera store can regale you with
tales of the questions they were asked about film and film cameras.

In another ten years, they'll have even wilder tales about digital
cameras and the questions people ask about them.

I actually don't recall seeing claims made that digital solves "all
problems" though I'm sure you could find someone who would say that.

Anyone who claims that digital will eliminate film is effectively saying
that.

--
Transpose hotmail and mxsmanic in my e-mail address to reach me directly.

"Mxsmanic" wrote in message
...
David J. Littleboy writes:

If that's what they want, how is that a problemg?

It's not, unless you are trying to use such people as an argument to
support the assertion that digital is taking over from film.

If that's what they needed, and film wasn't doing what they wanted, then
digital is taking over _that segment of the market_ from film.

David J. Littleboy
Tokyo, Japan

"Mxsmanic" wrote in message
...
Gregory W Blank writes:

If this really became a legal, issue I would guess the source of
the image generation could be analyzed to determine
if the origin was compromised.

In reality, there's a simpler way: You have the photographer testify in
court that the images shown in court were indeed the images he took.

Yes. My understanding is that this is exactly what happens, and the digital
is completely equivalent to film for legal purposes: film can be faked too,
so the checks were already in place.

David J. Littleboy
Tokyo, Japan

"Mxsmanic" wrote in message
...
MikeWhy writes:

... and also couldn't distinguish a good print from the crap the
mini-labs
now spew out.

The minilabs aren't doing that anymore. The new digital minilabs, such
as the Fuji Frontier, produce stunning prints even from poorly exposed
film. The days of really bad one-hour prints are largely history now.

"Largely history now" doesn't yet apply to minilabs in and around Chicago,
at least not as of two months ago. They have trouble with anything
approaching a contrasty scene; about five stops from full black to burnt
white. Their scans are just as bad as their prints. The negs were fine. I
scanned and printed them myself.

In article , "MikeWhy"
wrote:

"Largely history now" doesn't yet apply to minilabs in and around Chicago,

Chicago, eh? Where? I used to live near 53rd and Blackstone, then Broaday
and Buckingham... or are you in the suburbs? Do not even tell me if it is
a suburb.