2014-02-26

both empirical (easy way) and mechanistic (hard way) are supported

mathematically by the ICC, but you could do your own system

http:/www.color.org

empirical characterization entails printing an equipment code value

target to the "calibrated" equipment and relating it mathematically as a

profile to the color of the profile connection space, usually cubic, a

three dimensional profile for 3 colorant mediums, I know there are at

least or there once was 4 colorant mediums from Fuji, I'll allow you to

derive this from my post yourself, it is not hard if you know it

even B&W colorants like silver halides have a hue that must be either

maintained or translated in the ICC profile like a three colorant

system, the eye is a three colorant system, I will allow you to derive

B&W yourself, it is not hard if you know it

with the advent of RIMM, ERIMM, and ROMM in ICC you can use digital

manipulation for hybrid systems (you can search for these on the ICC

site and they are from ProPhoto RGB according to wikipedia)

so why would you want to do it the hard way, mechanistically?

1) want to retain analog manipulation methods

2) want to have analog manipulation algorithms within digital

3) want to an analog capture of scene colorimetry

4) multi-stage analog/hybrid systems do not calibrate

(steady-state calibration is a prerequisite for profile characterization)

5) want to design new analog equipment or manipulation

6) want to design new sensitized media for a hybrid system

( a film program was around 5 million at Kodak 17 years ago)

7) want to design a better analog RIMM, ERIMM or ROMM

so how to do it the hard way?

first, you will need a lot of information, the preferred way of getting

this method is from analog media, equipment and software companies, as

opposed to the investment yourself, some analog technology really

requires single layer coatings to resolve crosstalk from spectral

sensitivity and chemical processing, chemical processing can be just the

way it is, process variability across or inside labs, or by design with

things like DIR or DIAR couplers intended to reduce or optimize chemical

crosstalk
http://en.wikipedia.org/wiki/Color_motion_picture_film

Kodak has licensed some hybrid or analog technology to IMAX, the analog

industry may be willing to deal at this point, additionally some analog

and hybrid information may be patented, when I was at Kodak R&D many

things were not patented due to other nations not respecting

intellectual property, PhotoCD was patented as a last ditch effort to

leverage capture film into digital systems

so what type of information will you need?

spectral sensitivity of capture mediums

(for some systems digital capture sensitivity needs resolved to sensor

and filtration)

spectrophotometry of print (subtractive) output mediums

(spectral data might have to be resolved to light source and filtration)

spectroradiometry of display (additive) output mediums

spectroradiometry of analog and hybrid printers

(for some systems such radiometry of equipment needs resolved to light

source and filtration)

chemical colorant response to light of medium (DlogE)

interimage, overall crosstalk of medium

single layer coatings of mediums to resolve chemical versus sensitivity

crosstalk

what are the use cases?

1) captures (digital, hybrid or analog)(scene or like printing density)

2) manipulations (digital, hybrid or analog)

3) outputs (digital, hybrid or analog)

spectral information is a one dimensional look-up table without crosstalk

crosstalks are at least a linear matrix

DlogE is best represented with a rational quadratic, higher math effects

the central linearity, complete linearity effects toe and shoulder,

highlight and shadow detail where dynamic range is low, this is still a

one dimensional look-up table

digital contrast is linear, gamma

hybrid input/output contrast is calibrated for gamma in most cases

multi-stage systems typically use some standard assumptions, mostly what

equipment/software/measurement the systems engineer is working with

any mathematician can take it from here to get all use cases

if you want me to do a use case, just reply, I have a lot of time on my

hands

by the way, there is a book about "making" Kodak film, but not

"designing" it, maybe the author might want to add a understandable

compilation of this to his book
http://www.makingkodakfilm.com/

--

Dale

Show more