The Mostly Color Channel

Assessing color reproduction tolerances in commercial print workflow

2012-01-28T17:21:00.000-08:00

The presentation of this paper was somewhat hasty, because I forgot to finish the slides. I only realized this while I was setting up my laptop and quickly thumbed through the slides. I only had the short time during the break to quickly assemble the presentation by copying chunks from the paper, while also trying to help Dr. Tastl who was having a problem getting PowerPoint to recognize the projector. I guess this is what happens when we are burnt out…

Anyway, I made it. The slides are not great, but the presentation was OK and I believe the paper contains every detail. Here are the hasty slides:

Assessing color reproduction tolerances in commercial print workflow

View more presentations from Giordano Beretta

Unfortunately SlideShare had some problems parsing the uploaded PDF file. The original PDF can be downloaded from here.

The paper is available with Open Access through this link: http://dx.doi.org/10.1117/12.911899

The citation is:

Giordano B. Beretta, Eric Hoarau, Sunil Kothari, I-Jong Lin and Jun Zeng, "Assessing color reproduction tolerances in commercial print workflow", Proc. SPIE 8292, 82920U (2012); doi:10.1117/12.911899

Finally, here is the abstract:

Except for linear devices like CRTs, color transformations from colorimetric specifications to device coordinates are mostly obtained by measuring a set of samples, inverting the table, and looking up values in the table (including interpolation), and mapping the gamut from input to output device.

The accuracy of a transformation is determined by reproducing a second set of samples and measuring the reproduction errors. Accuracy as the average predicted perceptual error is then used as a metric for quality. Accuracy and precision are important metrics in commercial print because a print service provider can charge a higher price for more accurate color, or can widen his tolerances when customers prefer cheap prints.

The disadvantage of determining tolerances through averaging perceptual errors is that the colors in the sample sets are independent and this is not necessarily a good correlate of print quality as determined through psychophysics studies. Indeed, images consist of color palettes and the main quality factor is not color fidelity but color integrity. For example, if the divergence of the field of error vectors is zero, color constancy is likely to take over and humans will perceive the color reproduction as being of good quality, even if the average error is relatively large. However, if the errors are small but in random directions, the perceived image quality is poor because the relation among colors is altered.

We propose a standard practice to determine tolerance based on the Farnsworth-Munsell 100-hue test (FM-100) for the second set and to evaluate the color transpositions—a metric for color integrity—instead of the color differences. The quality metric is then the FM-100 score. There are industry standards for the tolerances of color judges, and the same tolerances and classification can be use for print workflows or its components (e.g., presses, proofers, displays). We generalize this practice to arbitrary perceptually uniform scales tailored to specific applications and present an implementation.

In essence, we propose to extend the color discrimination test procedures used to evaluate human observers, to mechanical and electronic color reproduction devices.

Harmonious colors: from alchemy to science

2012-01-28T17:03:00.000-08:00

Last weekend three storms swept through the Bay Area and it was a good thing, because it cleaned up the very dirty air. The attendees of Electronic Imaging enjoyed a perfect weather.

At the session on the Dark Side of Color, I gave a presentation on my thoughts about the discussion in the color language workgroup meeting at the last AIC conference, which was held in Zurich. I would like to thank Dr. Michael H. Brill for asking a particularly good and relevant question.

Harmonious colors: from alchemy to science

View more presentations from Giordano Beretta

Unfortunately SlideShare had some problems parsing the uploaded PDF file. The original PDF can be downloaded from here.

The paper is available with Open Access through this link: http://dx.doi.org/10.1117/12.915839

The citation is: Giordano B. Beretta and Nathan M. Moroney, "Harmonious colors: from alchemy to science", Proc. SPIE 8292, 82920I (2012); doi:10.1117/12.915839

Finally, here is the abstract:

There is a very long tradition in designing color palettes for various applications. Although color palettes have been influenced by the available colorants, starting with the advent of aniline dyes there have been few physical limits on the choice of individual colors. This abundance of choices exacerbates the problem of limiting the number of colors in a palette.

The traditional solution is that of "color forecasting." Color consultants assess the sentiment or affective state of a target customer class and compare it with new colorants offered by the industry. They assemble a limited color palette, name the colors according to the sentiment, and publish their result.

The color forecasting business is very labor intensive and difficult, thus for years computer engineers have tried to come up with algorithms to design harmonious color palettes, alas with little commercial success. Contrary to the auditory sense, there is no known physiological mechanism sustaining harmony and the term "harmonious" just has the informal meaning of "going well together."

We argue that the intellectual flaw resides in the belief that a masterful individual can devise a "perfect methodology" that the engineer can then reduce to practice in a computer program. We suggest that the correct approach is to consider color forecasting as an act of distillation, where a palette is digested from the sentiment of a very large number of people. We describe how this approach can be reduced to an algorithm by replacing the subjective process with a data analytic process.

The First Time Ever I Heard Your Face

2012-01-24T12:33:00.000-08:00

Neil Harbisson is a color-blind (achromatopsia) artist from Spain who has a cybernetic "third eye" attached to his head that enables him to hear color. This also makes him a genuine cyborg. Since 2005, Harbisson has used his sonochromatic retina to design sound portraits of famous people. The first person he experimented on was the immediate heir to the British throne, HRH The Prince of Wales.

He scans the eyes, hair and skin color of his subjects and works the individual notes into a musical chord. Harbisson explained, “Prince Charles noticed my electronic eye so, I politely asked him if I could listen to his face.” Apparently Prince Charles' lips sounded like a high E [a blue blood? --njg]. But his hair was almost inaudible—musically thin due to male-pattern baldness.

Some notable quotes from a recent BBC Outlook interview:

Color as words are "really, really, really, impossible to understand"
"Color has a frequency that we can't hear"
"Red is between F and F^#" [? I would've thought it was A/A^#. --njg]
"I hear the color through my bones, not through my ears"
The BBC interviewer's voice is "between orange and red"
Neil's fave "color" is Aubergine, which has a high pitched tone
"White is silent" [? I would've thought that was black. --njg]

And finally, here is Neil with his Eyeborg on daily maneuvers (video).

Related post: The Colorful Blind Painter

R&D not sufficient for success

2012-01-20T11:36:00.000-08:00

As a follow-up on our previous post, the Economist has an interesting blog post Gone in a flash, which delves in the problem that for a technology company research is necessary but not sufficient for success, as I had pointed out in an earlier analysis of the fruits of R&D investment over a long time period.

An interesting comment in the Economist's blog post is that mergers and acquisitions are not necessarily useful. As Geoffrey A. Moore wrote in his latest book, the acquisition of a company is only fruitful if the buyer already has knowledge of that company's technology, so it can digest it.

If R&D is necessary, is it sufficient that a company must be able to digest research to feed its business? Digesting research is very difficult; maybe this is why companies fail over time: they are unable to find the leaders with this skill.

Why is Kodak near death while Fujifilm is thriving?

2012-01-17T19:23:00.000-08:00

Fascinating perspective in The Economist. Here are some quotes:

Fujifilm, too, saw omens of digital doom as early as the 1980s. It developed a three-pronged strategy: to squeeze as much money out of the film business as possible, to prepare for the switch to digital and to develop new business lines.

Kodak had become a complacent monopolist. Fujifilm exposed this weakness by bagging the sponsorship of the 1984 Olympics in Los Angeles while Kodak dithered. The publicity helped Fujifilm’s far cheaper film invade Kodak’s home market.

Another reason why Kodak was slow to change was that its executives “suffered from a mentality of perfect products, rather than the high-tech mindset of make it, launch it, fix it,” says Rosabeth Moss Kanter of Harvard Business School, who has advised the firm.

Hindsight is always 20/20 but that last quote is reminiscent of the difference in business philosophy between Microsoft and Apple. One wonders what Steve Jobs might have said about that. We do know what Bob Lutz (former Vice Chairman of General Motors) thinks about Ivy League business schools and MBA spreadsheet-based business strategies.

Postscript: See the Comments below for additional perspective.

Crows Remember Colors For A Year

2012-01-13T18:06:00.000-08:00

Researchers have recently found that crows possess a long-term memory that allows them to remember colors for at least a year, a talent they use to successfully select containers containing food in experiments based on color cues after extended intervals. "It is not easy even for human beings to remember visual color information for a year. Crows may be even better than human beings in a certain aspect of memory," said Shoei Sugita, a professor of animal morphology at Utsunomiya University who led the joint research with Chubu Electric Power Co. The finding came as part of a study that Chubu Electric, troubled by problems presented by crows' nests on power line towers, commissioned in 2008.

Source: Science & Technology News from Japan, December 2011 • Dr. Felix Moesner

Colored Time

2012-01-04T11:11:00.000-08:00

"I have a meeting at purple o'clock." Say what!?

Meet the TimeHue® clock that represents time in HSL color space.

Frankly, I don't get it. Looks to me like a huge impedance mismatch for cognition. I'd have to keep checking my watch to decode it.

Finding structure in large data sets

2012-01-03T19:53:00.000-08:00

In color science we do not have sufficient knowledge about the visual system to formulate analytical models. However, in the past two centuries we have accumulated sufficient knowledge, that we do not have to resort to machine learning approaches like hidden Markov methods either. We are able to come up with equations that correlate well with what is perceived.

One would then assume, that color scientists excel in the mathematical statistics branch of correlations. Alas, the practice is less glorious and we tend to rely on Pearson's correlation to gauge the strength of association between pairs of stochastic variables. The caveat is that Pearson's correlation captures only linear correlation.

Based on Shannon's information theory and entropy, in 1957 Linfoot developed the concept of mutual information MI. However, after 50 years of research it is still too intractable to fish in large data sets like those we get in crowdsourcing to discover the structure of the data. Unless we know what to look for, there is little hope for serendipity.

Fortunately, Reshov et al. have now come up with a new exploratory data analysis tool they call maximal information coefficient (MIC). MIC is general, in the sense it does not assume a linear association, nor any other function type. MIC is also equitable, in that it is robust with respect to noise. In the special case of linear associations, it gives the same results as Pearson's correlation.

Returning now to our large data sets, Reshov et al. have gone two steps further, developing a larger family of statistics they call MINE, for maximal information-based nonparametric exploration. In mathematical statistics, nonparametric means that no assumption is made on the random variable's distribution. They make available their software in the form of a Java program (this is the second step).

Their paper Detecting Novel Associations in Large Data Sets is in Science magazine Vol. 334, pp. 1518–1524.

Mechanical Turk

2011-12-31T14:47:00.000-08:00

For our studies in color naming we have used two kind of experiments to elicit color terms: traditional tightly controlled psychophysics experiments in our laboratory, and crowdsourcing. There is a third kind of experiments, which does not rely neither on our acquaintances nor on our fans on the Internet: paid subjects.

The concern with paid subjects is that they are self-selected people willing to sell their time at a rather low price, so we assume they are not the best representatives of the population at large. However, the same applies for psychophysics experiments, where the subjects tend to have a Ph.D. and to live a sophisticated life.

A cheap and convenient way to recruit paid subjects is Amazon's Mechanical Turk, which has been used by others for research in color naming and color palette design. John Bohannon recently wrote a short review on MTurk for social science studies in Science (link).

Turkers make only $1.80 to $6.00 an hour, so quite a few do not understand the task or are spammers who skim through the jobs and and give random responses wherever possible to accelerate the process. Gabriel Lenz, a political scientist at the University of California, Berkeley had to reject about 20% of his American and 50% of his Indian Turkers for those reasons.

Gabriel Lenz and Adam Berinsky, a political scientist at the Massachusetts Institute of Technology in Cambridge have teamed up with Gregory Huber, a political scientist at Yale University, to study the Turker population. And of course, they are using MTurk to do so. They recently replicated two classic survey experiments and a political science experiment. In each case, the data obtained with MTurk were consistent with published studies that tested people in laboratories.

Where did they end up?

2011-12-20T13:34:00.000-08:00

Sometimes people are in the news so relentlessly, that we almost think of them as close acquaintances. The American media system is so hyperactive, that except for people who are famous for being famous, these people disappear from the media's radar screen and go back to their normal lives after a short while. However, sometimes they make a career change and end up in unexpected places. I am always surprised by high tech people ending up in epicurean posts.

For example, Lew Platt, an HP CEO who in 1999 was pushed out because he was growing his company only at 15% instead of the over 100% of .com companies of the time (most of whom are no longer around), ended up becoming the CEO of Kendall-Jackson Wine Estates, a vineyard and winery in Santa Rosa.

One of the HP BoD members with the most heat in the media was Walter Hewlett, during the battle for the merger with Compaq. So what became of him?

Together with his sister Eleanor, who is the widow of Jean-Paul Gimon, also a former member of HP's BoD, he planted olive trees on his sunny ranch southeast of Merced and started the olive oil company Owens Creek.

This year's olive crop in California is down 65% due to cool weather and little sun last summer in Napa and along the California coast. Walter Hewlett's ranch got lots of sun and thus he got a very good crop of olives.

The flavor profile of his Quartetto Classico blend this year is the best he has ever gotten. His Sicilian blend has always been excellent. The fall 2011 Sicilian blend is just now being bottled and will be available from his web site and at local stores very soon.

The current Owens Creek bottle labels were designed several years ago by graphic arts designer Jessica Taich and are printed using an HP Indigo press down at Landmark printing in San Jose. Web site and marketing are run by Robert Boehm.

Need an extra eye?

2011-12-19T15:17:00.000-08:00

A natural bioelectrical current jumpstarts normal eye development in frogs, researchers have discovered—suggesting a new route toward repairing damaged or diseased eyes.

Almost all cell membranes have "ion channels" that let charged particles move in and out—the essence of an electrical current. But the first clue that bioelectricity might be critical to eyes came a decade ago when Michael Levin at Tufts University in Medford, Massachusetts, and his colleagues altered the number of ion channels in cells in different parts of a frog embryo and found that lens and retinal tissue formed outside the head. Later work by others showed that cells destined to become eyes had an excessive negative charge.

Levin's team has now verified that these pre-eye cells were hyperpolarized, produced DNA regulatory proteins important for eye formation, and did become a lens and retina. Modifying the function of ion channels in four-cell frog embryos led to eyes in the tail and on the gut, but only where cells experienced a particular voltage range, the researchers reported this week in Development. "Bioelectrical information is both necessary and sufficient for inducing development of the vertebrate eye," comments James Coffman, a developmental biologist at the Mount Desert Island Biological Laboratory in Salisbury Cove, Maine.

Read the full article My, Your Eyes Are So Electric.

color vision challenges in electronic imaging

2011-11-18T11:36:00.000-08:00

It has been a long summer and autumn with all interrupts disabled. Now that the product is finished and transferred, we can resurface and catch up with life, which is made easier by doing 脱藩 (dappan).

The SPIE just released a new video explaining how teaching cameras how to "see" as humans do is both an art and a science, and Edwin Land spent his career pursuing that goal. Here is the link: http://spie.org/x83130.xml?ArticleID=x83130

Given the recent events here in Palo Alto, the op-ed linked at the bottom of that page is also a good read.

The Colorful Blind Painter

2011-10-26T09:51:00.000-07:00

Turkish painter, Esref Armagan (shown seated in the upper left panel), has been completely blind from the time he was born in 1953. Nonetheless, he has been drawing and painting since childhood. Not only is he able to produce images with the correct shape and perspective—more importantly for readers of this blog—he is able to produce correct colors that he has never seen . The astonishing accuracy of his work is shown here in the other three panels and, as a result, he has held exhibitions in Turkey, Holland and the Czech Republic.

This being the 21st century, naturally his brain has been probed using fMRI and written up in Harvard Medicine:

"As expected, as Armagan drew, the frontal–parietal region of his cortex became active—this area is known to transform perception into two-dimensional imagery and to coordinate sensory–motor information in sighted and nonsighted artists alike. What surprised the researchers was the robust activity in Armagan’s occipital cortex, a region devoted to visual processing."

Glad that's all sorted.

Colorful Language

2011-08-29T17:44:00.000-07:00

Eleanor Maclure graduated from BA (Hons) Graphic Design at Nottingham Trent University in 2006 and worked as a graphic designer for a large international architectural practice until the start of 2010. She has studied part time for an MA in graphic design at London College of Communication.

Currently she is a postgraduate design student and is doing research about how we communicate color to each other, looking at some of the issues with understanding color names.

Her interest in how people talk about color stems from a range of sources; discussions about re-branding at her previous employer, the way colors are described in fashion trend reporting, and the fact that people have endless disagreements over the color of some objects due to our subjective experiences of color.

Eleanor has a survey that she doing for her research and you can help her by taking part at her survey at this link: https://www.surveymonkey.com/s/T2PCTBK.

Macallan RPS awards

2011-08-04T14:50:00.000-07:00

The Royal Photographic Society in London has announced the Macallan Royal Photographic Society Awards for 2011.

The Progress Medal and Honorary Fellowship, in recognition of an invention, research, publication or other contribution which has resulted in an important advance in the scientific or technological development of photography or imaging in their widest sense, goes to Rodney Shaw, President and cofounder of White Rose Digital, which provides user-friendly imaging-methodologies for digital photographers.

Phil Green, will receive the Davies Medal, which is awarded for a significant contribution in the digital field of imaging science. Instituted in 1998 and sponsored by Kodak European Research and Development, the medal is in memory of Dr. E.R. Davies, a former Research Director of their Harrow Laboratories.

Shaw and Green will receive their awards at the ceremony which will take place on 8 September 2011 at the Royal Society, Carlton House Terrace, London.

Color My Mother Chartreuse

2011-07-26T00:13:00.000-07:00

When I was a graduate student in physics, a friend of mine (who was more into art and poetry) invited me over to dinner at his place. While his wife was busy in the kitchen, we were chatting near a window in the late afternoon sunlight. Suddenly, he pointed at a bowl of fruit on a table near the window and asked me why the shadow it cast was colored purple and not black. Looking back on it, I think it was a test—that art vs. science thing. Nonetheless, I was in a profoundly philosophical mood and immediately rejoined: "It's an optical illusion. What's for dinner?" It would be another decade before I would even begin to realize how much I did not understand about color. I had no inkling then that vision and color perception are computational processes, that the brain is a differential analyzer and computed differences carry relative errors (perceptual illusions).

More recently, in a faint reprise of that illuminating but ancient episode, I was amazed to learn from Nathan and Giordano that the naming of colors is a similarly profound process, and since they are both experts, I could not be as dismissive with them as I was with my arty friend. On the contrary, I was forced to reflect on how I personally came to learn certain color names. In that landscape, my mother cuts a dominant figure.

My mother emigrated with her family from Glasgow, Scotland to Melbourne, Australia after her father was laid off from the Clydeside shipyards during the Great Depression of the 1930s. Naturally, they met the same economic depression in Australia. As a consequence, the older of the five children were forced to find work in Melbourne to support the family. Thus, my mother had to leave school at age 15 (legal, but a minor tragedy) and was apprenticed to a milliner. There, she learned about dyed fabrics, like felt, and how to match it with a variety of other colored fabrics; not to mention learning how to mechanically fashion an actual hat out of those colored fabrics.

Decades later, by the time I was midway through primary school, my mother re-entered the workforce to supplement our family income. Since my mother only wanted a part-time job, one of my aunts offered her a sales position in the successful dress shop that she owned. This meant my mother had to be up to speed with the latest fashion and color trends of the season, be able to mix and match different colored fabrics and, perhaps more importantly for clinching a sale, be able to match fabric combinations with the customer's coloring (hair, eyes, skin tone, etc.). None of this would have presented a problem because of the knowledge she had already acquired in her previous life as a milliner. She was a good match.

The reason I remember these events is because it was around this time that I started hearing strange words at the dinner table. Such words as: vermilion, maroon, turquoise, lavender, puce and chartreuse. It was those last two that really stuck with me because I could never seem to get their meaning straight in my head. The other names I was able to register fairly easily. Lavender was the same name as the plant we had growing in our garden, so I could literally see (and smell) that color. Vermillion and maroon turned out to be shades of red, which is my favorite color, so they got resolved swiftly. But puce and chartreuse I could never register no matter how many times I heard them. Unlike the other color names, there never seemed to be any convenient reference examples. My mother would sporadically utter those color names, I would hear them, I would recall that I had heard those words before, but they would just sit there in my mind: familiar but unresolved.

It's worth noting that, as a child, there's a tendency to live with some words and phrases having jumbled associations. For example, I had a great-aunt named May and her husband was named Bob. My father would say to me, "Time to get ready. We're going over to May and Bob's" (place). I heard this as may-and-bobs (a single word), which sounded to me like may-and-aise (mayonnaise). For the longest time, these two "words" were strongly associated in my mind. Similarly, the color term puce sounded very much like puke and therefore I registered it as a rather disgusting color without ever seeing it (not what I think today).

Asking my mother to explain by example seems like the obvious thing to do, and God knows I asked my father to explain things, about a million times a day. But that course of action would have been unwise in this case. For one thing, it would prove that I was snooping on the conversation and that might have meant my mother would become more cautious about what she said in the future. Keeping quiet at the dinner table meant I could potentially overhear any juicy bits—and believe me—there were quite a few of those. So, that price would have seemed too high.

For sure I looked those words up in a dictionary then, as well as many times since, but it really doesn't help with color names because it merely replaces one abstract word with another (for me, anyway) and I cannot recall the definition when I need it—which is next to never. It seems vital to make the visual association (probably more than once) to get it to stick, but I only heard those particular color names from my mother when she was talking to my father. Although I attended A-grade schools, I surely never learnt these more exotic color names in the classroom, and I most definitely never heard them used in the schoolyard. Even our standard issue coloring pencils came as a box set of 72 shades that we always referred to by number, not by name. Moreover, I should stress that I was mostly not paying attention to the adult conversation going on at the dinner table. In this casual verbal fog, if the word association occurred easily, I got it. If not, too bad because there was no necessity to resolve such weird words. I was certainly not going to throw the word chartreuse around at school, for fear of being beaten to within an inch of my life due to showing off. So, thanks to my mother, the color name chartreuse lodged in my memory but remained dormant and fuzzy for lack of reference and usage.

Indeed, it was only a few years ago, while I was teaching in Grenoble, that I was introduced to Chartreuse the liqueur and the local abbey where it originated. In this way, the word chartreuse finally became resolved for me. Well, almost. There is green and yellow chartreuse—no wonder I was confused! So, my mental reference for chartreuse has finally become the liqueur (although I prefer Liqueur de Chataigne as an digestif). I continue to suffer from puce deficit. But it's clear that it was not like that for my mother, in particular, or women in general. Their associations for color names come from a wide variety of experienced colors that include colored fabrics. How else could my mother have successfully sold dresses to other women in my aunt's shop? And this dynamic is supported by recent research that suggests an extended color vocabulary enables women to perceive the world more richly than men. Listen to this April 2011 BBC interview with Prof. Galina Paramei starting at 8:08 minutes. I can attest to my mother completely outclassing both my father and me when it came to the business of colors.

I'm certain that my mother probably sold hundreds of chartreuse dresses without ever knowing the true origin of that color name. And she would've been green with envy at my having visited the French monastery. Conversely, I never sold a dress in my life (and I don't intend to start now) but, thanks to my illustrious HP colleagues, I know more about the science of color naming than either my mother or I could ever have visualized.

Atlantis Descends

2011-07-22T18:23:00.000-07:00

STS-135 re-entry as seen from the ISS [Source:NASA]

The Pauli Effect

2011-07-21T09:55:00.000-07:00

Spin down

My favorite Pauli-effect story has to do with Walter Heitler defending his thesis topic or giving some kind of lecture. After the lecture, Wolfgang Pauli (in typical form) got up on the rostrum and launched into an expansive critique whilst pacing up and down. At some point he was headed towards Heitler, who was by now sitting in a chair at the end of the podium. As Pauli came closer and closer, Heitler leaned further and further back in the chair until he suddenly fell off the end of the stage: at which point some bright spark (possibly George Gamow) called out "Pauli effect!"

We Call it Brown. They Call It 'Weekend in the Country'

2011-06-30T16:27:00.000-07:00

Reader I-Jong L. sent us a pointer to this New York Times article:

We Call it Brown. They Call It 'Weekend in the Country.'
By KATHARINE Q. SEELYE
Published: June 30, 2011
In a redoubled effort to capture consumers' attention, paint companies are hoping to distinguish their brands with names that tell a story, summon a memory or evoke an emotion.

http://www.nytimes.com/2011/06/30/us/30paint.html

Which Path? That Path

2011-06-28T11:18:00.000-07:00

A few years ago we (Neil J. Gunther, Edoardo Charbon, Dmitri Boiko, and me) where interested in quantum imaging and experiments confirming Bohr's principle (click the quantum imaging tag in the tag cloud at right). We came up with the concept of photon twinning and understood well how the various order correlation functions relate, which led to a single photon detection camera developed at the University of Delft by Edoardo Charbon, which by postselection can distinguish the photons of its flash light from those of the ambient light (sun).

Maximal values of respective correlation functions for incoherent, coherent and thermal light states
correlation function	photon states
correlation function	incoherent	coherent	chaotic
g⁽¹⁾(x, 0)	0	1	1
g⁽²⁾(x, 0)	1	1	2
∆g⁽²⁾(x, 0)	0	0	1

Those results are published in the two papers http://www.iop.org/EJ/abstract/1367-2630/11/1/013001 and http://www.opticsinfobase.org/oe/abstract.cfm?URI=oe-17-17-15087. The paper Observing the Average Trajectories of Single Photons in a Two-Slit Interferometer by Sacha Kocsis et al. in Science magazine of 3 June reports on related work:

A consequence of quantum mechanics and the Heisenberg uncertainty principle is that complementary variables (for example, position and momentum) cannot both be determined precisely. Measuring one variable necessarily results in loss of information about the other. The best example is the two-slit interferometer and the interference pattern that occurs when light or single photons or electrons are transmitted through it. Determining which slit the particle goes through (position) destroys the interference pattern (momentum). Kocsis et al. implement a recent theoretical proposal in which an experimental protocol involving weak measurements could answer the "which path did the photon take" question. The results may impact the foundations of quantum and classical physics and potentially find practical application in metrology.

Science 3 June 2011: Vol. 332 no. 6034 pp. 1170-1173 DOI: 10.1126/science.1202218

pre-press is dead

2011-06-27T12:14:00.000-07:00

Managers sometimes argue that it is not necessary to attend conferences, because the papers can be read more efficiently in the proceedings. As several post in this blog prove, this is not true, because there are all the discussions in the Q&A periods, breaks, receptions, etc.

One tidbit picked up at the last AIC meeting is that a report will soon appear proving electronic displays are now equivalent to paper in reading efficiency and comfort. It is an easy guess, that in the near future Apple will apply its 326 ppi retina display to the iPad and Samsung will do a corresponding move with its AMOLED based One Cell Touch display OCTA on its Galaxy line. Add E Ink's Triton and it becomes clear that squirting ink on dead trees is a thing of the past. Adobe's latest Creative Suite release is testimony to this shift.

Accordingly, ~~pre-press~~ is a dead word. Please write or say pre-media from now on.

AIC Study Group on the Language of Color (LC)

2011-06-27T08:52:00.000-07:00

During the AIC meeting in Zurich, the AIC Study Group on the Language of Color (LC) held a meeting, moderated by the Chair Prof. Jinsook Lee. During the meeting, the delegates discussed two project proposals by Co-Chair Prof. Paul Green-Armytage.

The first proposal was as follows:

The eleven 'basic colour terms' have been mapped in an array of Munsell colour chips for several languages including Korean and English. This can make it possible for speakers of Korean and English to see the ranges of colours that would be described by the colour terms of each others' languages. However, the ranges of colours that are described by the different names vary greatly in extent. For example, there are many more 'greens' than 'yellows'. It might be useful to divide colour space into blocks of roughly equal size, take the focal colours from each block and then ask speakers of different languages to name the focal colours. The focal colours could then become a kind of basic AIC palette with names for each of the colours in several languages. This could serve as a bridge between everyday languages, as spoken in different countries, and the colour order systems such as Munsell, NCS and CIELAB. I think I sent you my paper on 'Colour Zones'. That has 27 named focal colours at level two and that could be a possible model. But there may be better ideas. Giordano Beretta will be at the conference in Zurich and he has done a lot of work on colour naming including an internet based project which he calls 'crowd-sourcing'. People were invited to name a set of colours displayed on their screens and he derived consensus names from that process. We might ask him to become involved. We could decide on a set of colours that we think would be a useful range to have named in different languages and then use the Wiki-workspace. People could be invited to log onto the Wiki site and contribute ideas for naming the set of colours. Do you know Giordano? I met him at AIC 2009 in Sydney and could contact him about this if you think this is a good idea.

At the meeting, Prof. Osvaldo da Pos summarized the core of the proposal as follows:

Isaac Newton tried to express color perception with 7 spectral color terms. Berlin and Kay then tried to do it with 11 basic color terms. Paul Green-Armytage is proposing to take it to the next level with a set of 27 named focal colours.

There are two fundamental reasons why in my view this proposal, with all due respect, might be somewhat misguided.

The first is that it has been known for many decades that when one plots color terms in a uniform color space, the color terms do not fill the color space uniformly, respectively are not located on a regular grid. Rather, the color terms form a foam in a uniform color space. Here are some visualizations by various authors:

Kenneth L. Kelly and Deane B. Judd (1955):

Robert M. Boynton and Conrad X. Olson (1987):

David L. Post (1992):

Shigenobu Kobayashi (1992):

Antal Nemcsics (1993):

Heinrich Zollinger (1999):

Tsuei-Ju Hsieh (2011):

The years here refer to the publication from which I took the figure, not the first publication of the figure. Anyway, I hope this is a sufficient visual proof that the distribution of color terms in a uniform color space is more like a foam than a set of focal points on a regular grid. For example, on page 3 of their 1955 book, Kenneth L. Kelly and Deane B. Judd write:

The 1933 recommendations by I.H. Godlove included a 20-point division of the hue circle for colors of moderate saturation, a 10-point division for weak colors and a 5-point division for very weak colors. These recommendations were followed closely at first with the thought that each color designation should refer to about the same fraction of the Munsell hue circuit. However, it was soon evident that deviations from this plan were necessary to make the designations accord with usage at that time in the National Formulary and the United States Pharmacopoeia, and more recently with usage in the textile industries and by the general public.

My second problem with the proposal is the approach itself. The proponent is taking the stance of the philosopher who has found the lapis philosophorum (philosopher's stone) and thus is the holder of some absolute truth. During the meeting, he kept repeating:

27 is the number of colours I can wrap my head around

To my knowledge, a color scientist's head circumference is not a constant of nature like π, h, or e, therefore I do not see why the AIC should standardize it. The custom of making arbitrary philosophical assumptions like the color zones or I.H. Godlove's subdivisions comes from the tradition of alchemy.

For example, Lorenzo Lotto's Enterprise of Creation may be cute, but if you click on the figure to reveal the original before the "Hello Kitty" treatment, you discover a lot of information, from the transformation of chaos into splendor to all the numerology of the ten Sephiroth of Kabbalah, the ten circles of the cosmological enterprise, the forty initiations to capture light and reach the philosopher's stone, etc.

All this is deep, interesting, and had an important impact on technologies created by the alchemists, but it is not how we do science today. Today's tradition follows from the teachings of Iraqi scientist Abu Ali al-Hasan ibn al-Haytham (965–1039) — or Leonardo da Vinci in the case of color science — which is to conduct experiments to collect data and analyze it.

Data is king. We are not interested in 7, 11, or 27 colors. We collect vast amounts of data and then analyze it to find fundamental principles helping to solve a specific problem. We use techniques like mathematical statistics, data mining, and machine learning to find the answers to our questions.

Our aim as color scientists is not to find some platitudes on a small number of colors. Rather it is to give people the knowledge and tools allowing them to take action and make commitments, rather than just accumulate information. Therefore, in a frequency plot of color terms, we are interested in the long tail: the locus of valuable information.

Which color terms are relevant and how they should be structured is an answer we have to reconstruct each time from a vast data corpus, depending on the application we are addressing.

When we can draw from a gigantic data corpus, we are not restricted to synchronic color terms. Indeed, we can explore the ephemerality of diachronic color terms:

The above figure (click on it for an enlargement) illustrates the diachronistic evolution of the synonyms of cyan over 200 years. We learn that aqua has become less common, while turquoise has emerged. Note also that the color term aqua does not correspond to the color term 水 (mizu), which are the Latin, respectively Japanese, translations of water. But even in a single language in a point in time, the color for the term aqua depends on the context, as we illustrated in the post on the color of water.

Jean Gastinel's Memorial Service on 6/26/11

2011-06-25T09:58:00.000-07:00

Jean passed away after a sudden tragic accident on 6/8/2011.

Jean's memorial service is on Sunday 6/26/11. The memorial service will be held at:

Valley Presbyterian Church
945 Portola Road
Portola Valley, CA 94028
Sunday, June 26, 2011 2:30 - 4:30 p.m.

Reminder: reduced functionality June 24-26

2011-06-24T11:18:00.000-07:00

This blog will have reduced functionality from Friday 24 June 23:00 h UTC to Sunday 26 June 23:00 h UTC due to a scheduled power outage. Two of our name servers and the server with data, applications, and media will receive an UPS (Uninterruptible Power Supply). Only the name server in Europe and text will function normally, as well as the media hosted on external servers.

EI 2010 color naming paper now open access

2011-06-23T11:01:00.000-07:00

Thanks to the generous support of our sponsor, our EI 2010 color naming paper is now open access, i.e., the download is free. The copyright belongs to SPIE: if you have the bits on your server, please remove them and replace them with this link: http://dx.doi.org/10.1117/12.846957. Of course, you can store a copy for personal use on your own computer.

The citation is as follows:

Giordano B. Beretta and Nathan M. Moroney, "Color naming: color scientists do it between Munsell sheets of color", Proc. SPIE 7528, 75280V (2010); doi:10.1117/12.846957

The paper introduces such important concepts as automatic color term translation through colorimetry and crowd-sourcing, as well as the experimental proof that color naming on emissive displays correlates to color naming on reflective media. This paper is also suggests the use of widely available standards such as the Munsell Sheets of Color in order to compare the results of different experiments.

As a reminder, here are the links to our other open access color naming papers:

Is it turquoise + fuchsia = purple or is it turquoise + fuchsia = blue? http://dx.doi.org/10.1117/12.872581
Toward Robust Categorical Color Perception http://www.hpl.hp.com/techreports/2009/HPL-2009-146.html
Cognitive Aspects of Color http://www.hpl.hp.com/techreports/2008/HPL-2008-109.html

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