Your Personally Identifiable Information (PII)

In my 16^th of May post on Your Portrait, I mentioned HP's stringent privacy rules. Now that we are on a commercial platform, we can be stricter about privacy.

As you may have noticed, you can now comment anonymously, i.e., without HP Passport. We will now be strict about rejecting any comment with personally identifiable information (PII). When you submit your comments without personal contact details, we will be happy to publish them; if you miss your comment, resubmit it without PII, as we have no way to get back to you. Also, if you log in using HP Passport, make sure your user ID is not your email address (instructions on how to change your user ID are on the login page). Thanks!

Of course, comments with other's PII, especially when defamatory or character assassinations, violate the HP Standards of Business Conduct and are also rejected, as explained in the post on Snakes in Suits.

See you soon

We wanted to let you know that HP blogs will be migrating to a new platform over the next week. As of Friday, May 23, we won't be posting to our blog and won't be able to receive any comments submitted. Please hold your comments until June 1 when our new site will be live.

Publish or perish

Being an old person, my formative years were in a quite different publication ecosystem. Although I studied at a world class elite school, the new publish or perish system had not yet reached our mathematics department. It was believed that a mathematics professor has about one breakthrough idea every two years and hence it was expected he or she submits a paper to the journal every two years and that the paper will be published after a substantive review and revision.

For the students, the first two years were spent in the basic studies, while the third and fourth year were spent in specialization and learning how to perform research. We were doing the latter through seminars, where each student was assigned a fundamental paper to study and explain. The papers were difficult and required researching the literature; the result was a seminar presentation.

At the end, four months were spent in real research in the form of a diploma thesis, which was printed in half a dozen copies for the collaborators. When continuing with a doctorate, a conference presentation was made at the beginning, to make sure that one would not embark in research already done. At the end the dissertation was printed in about a hundred copies for library exchanges and for colleagues working in the field. The main result was also published in the form a technical report and sometimes as a paper.

Today, journals receive a large number of manuscripts at the seminar level. It appears that every master thesis is submitted for publication in a journal. Since the level of research has not changed, this means that journals are swamped with bad manuscripts. With bad I mean they do not present novel original research results and they convey everything the author has learned instead of being concise.

People may say that a given journal is first tier because it rejects 80% of the submitted manuscripts. Unfortunately the contrary is true — when a journal is first tier it gets swamped with 80% crap. You may argue, so what, the system works.

Actually, it works at a very high cost. Every manuscript still needs to be reviewed, and because reviewers are swamped, the reviews are getting less and less useful. This way the research process as a whole suffers because the feedback from peers is less conductive to improved quality. Also, even when the editorial process runs on a volunteer basis, a large staff is still required to get the manuscripts moving through the review process, increasing the price of journals.

One may be tempted of incriminating grant giving organizations, because they created the publish or perish system in the first place. However, these organizations work in the interest of society, and are interested more on impact and quality than dry artificial metrics. In my view, the responsible are the professors or research managers who are not diligent in screening what they allow for submission to a publication.

To finish on a positive note, I would like to share with you what I think was the best paper that crossed my desk in 2007. The paper appeared 1 August 2007 in Optical Engineering 46(08), and was written by Yael Termin, Gal A. Kaminka, Sarit Semo, and Ari Z. Zivotofsky. The title is Color stereoscopic images requiring only one color image and you can get it at this link.

This paper addresses the application and advancement of creating practical 3D stereoscopic visual scenes, and does so in a well-written fashion. Through the use of an antique stereo scope (from 1905) and a high tech Head Mounted Display (nVisor-SX HMD) the investigators show to 11-15 subjects paired stereoscopic images. These images are either both color, both gray scale, or a mix of one color and one gray scale. The results support the investigator's hypothesis that there is no significant difference between the percept of depth between the color/color images pairs and the mix image pairs. There is a slight decrease in the perception of color intensity but this seems to be negligible. The finding is novel and important to the field of optics and visual perception.

I hope you will read it and consider it a benchmark for your next manuscript submission.

Your portrait

One of the American strengths in the global economy is the demographic knowledge about itself. No other country publishes high quality statistical data as fast as the US, and nowhere else have companies such intimate knowledge of their customers. Nevertheless, HP's blogs are subject to very stringent privacy rules, and we know very little about You, our reader.

True, our Mostly Color blog readers are shy and prefer to comment via email, but not everybody comments, so we know very little about You. The only data we receive is a spreadsheet with the minimal data necessary to administer our performance appraisals.

Knowledge of the customer — or reader in this case — is important to decide which of the facts we see when we look out of our window we should blog about; after all, we are promising to divulge information that allows you to take action and make commitments. So I threw the April data we just got into pro Fit to see what we can interpolate.

The first statistical tidbit is that you are not just reading our blog as we write it. In fact, although we just wrote a few posts, 146 pages were visited. By the way, a visit is the collection of the pages you visit during a session. For example, if you start from a page and then follow links to previous posts, it counts only as one visit. I am looking at visits instead of views, so I can limit the data to the posts you where interested in first and ignore deambulations.

The first plot tells me that there are some posts that are wildly popular. Considering this is a more arcane blog reporting on news like non-local realism, compared to for example The Digital Mindset Blog reporting on Gwen Stefani, this is a surprising data point. Hmm, Nathan posted An On-Line Color Thesaurus half a year ago on October 29, 2007 and still had 1392 visits last month; I guess that is what would be called an evergreen.

The time on the ordinate is in minutes, so pages with zero time are the ones you dismissed after a cursory glance. Fittingly, more time was spent on the more popular pages. There are quite a few visits to pages read for more than two minutes, which tells us, that the level is about right for our audience.

Interpolation allows us to get a little more out of the data. First lets us categorize it. I should have taken the tags on each post, but that would have taken me too much time, so I just quickly make up nine categories and get

The color on the legend at the right is the reading time in minutes, and visits are the number of times a post was visited upon first reaching the blog. Yellow areas indicate were we hit your interests on the spot.

Posts on color science are most popular for diligent readers, with Nathan's tool posts hitting the jackpot. Surprising is the popularity of the trivia posts, where we mostly blogged about a particular color. We should do more of them.

The encouraging datum is that there are no categories that flopped, meaning that our eclecticism is in the correct ballpark for our readers. Actually, let me replot this with a linear scale and focussing on the posts with hundred or less visits, which are more the typical posts.

This confirms that each category has an attentive readership, mostly so the posts related to color science, hence the blog title is appropriate.

A fresh view of lasers

We are all familiar with conventional lasers, where light is confined between two mirrors defining laser cavity modes and laser frequency. The light is trapped long enough for amplification by a gain medium (atomic vapor, solid, or dye) to be efficient. These lasers are in our CD and DVD ROMs and players, bar code readers, and the head stations that light up optical fiber.

Recently, progress in nanotechnology has brought us laser paint as a robust and inexpensive source of coherent light. These random lasers are representatives of nonlinear disordered optical media that are studied in the physics of disordered systems under non-equilibrium conditions.

Laser paint consists of a random aggregate of nano-particles which scatter light and have gain or are embedded in a background medium with gain. In a variety called diffuse random lasers (DRL) the diffusive escape of light is so rapid that such lasers exhibit no isolated resonances in the absence of gain.

DRLs are completely different animals from conventional lasers, and the standard laser theory explaining lasing in terms of Fabry-Pérot interferometers or etalons analogy cannot explain laser paint.

Recently Hakan Türeci of the ETH in Zurich and his collaborators have developed a theory able to treat the DRL rigorously and provide results on the lasing spectra, internal fields, and output intensities. In essence, they have developed a unified picture of laser physics.

By substituting the role of linear cavity resonances with a new set of modes, they found a simple analytical expression from which all of the properties of any laser structure can be derived, given a knowledge of the dielectric constant profile of the system together with the main parameters characterizing the amplifying material.

Their work could spark a new branch of nonlinear dynamics in which phenomena such as optical bistability or multistability could be explored in novel types of lasing structures. Read more on their web site.

Aftermath: surviving psychopathy

As this blog's title suggests, we are not just writing about color perception. This is a good time to put some entropy in our blog. Last summer I reviewed a few books on psychopathy, which generated quite a bit of feedback email. Here is an update.

Very loosely I started with a Science magazine paper on contributors, slackers and quitters, and then moved over to a book with a perspective from a psychologist specializing in psychopath victims, Hare's classical Without Conscience, to the more more updated book on psychopaths in the next cubicle, and finally to a book taking a broader perspective in time and from neurosis to psychopathy. According to the blog traffic log, these posts are still of great interest, so I think I should give an update.

In the past 15 years we have learned a lot on the functioning of the brain, and there is strong evidence, that when the brain gets rewired from back to front during adolescence, in some people with a genetic predisposition the speech area does not get wired up to the bilateral inferior frontal gyrus, preventing the development of emotions and of the conscience.

As described in Snakes in Suits, we are increasingly exposed to psychopaths at work. Yet, only few of us have access to an fMRI system at work and even when we do, it may not practical to scan the potential psychopaths in our lives. Since there is no test that can administered by us laymen and psychopaths are not required to wear a bell, we are confronted with the problem of having to deal with the psychopath's victims.

I received an email from a prominent researcher in this field, that a web site for people with psychopaths in their lives has been set up under the name Aftermath: Surviving Psychopathy. It has several forums and a very useful Primer on Psychopathy by the foremost experts David Kosson and Robert Hare themselves, as well as a number of links to other resources.

If you think there might be a psychopath in your life, check this aftermath web site. If you know somebody who you think might be a victim, send them this link.

The mistery of stable images

We know optically the eye is like a simple meniscus camera that projects an image onto the retina. We also know that on the cortex there is a holomorphic map of the visual field. However we know very little of what happens in between. For example, in the lateral geniculate nucleus (LGN) there are seven layers, and if we stick a toothpick in a point like in a club sandwich, the layers are geometrically aligned.

But the human visual system (HVS) is not like a camcorder. Here is a simple test: take a camcorder and film what while you move down the street. Try doing this while walking, running, riding a camel, riding in a sports car. While you are doing this, each time you see the same scene.

Now remove the context, i.e., sit on a chair and watch what you filmed. The sports car piece will probably just be blurred, the other pieces will probably give you motion sickness and you will not make out much visual information. If you ever used a virtual reality system you know what I mean.

Add to this that you keep moving your head, and between fixation points your eyes keep saccading. We must conclude that the map on the cortex is not an image of the retina but an image of the real world. How does the HVS perform this feat?

Tim Gollisch of the Max Planck Institute of Neurobiology and Markus Meister of the Department of Molecular and Cellular Biology and Center for Brain Science, Harvard University have solved this riddle and published their data on page 1108 of Science 22 February 2008.

The trick is performed by the retinal ganglion cells, which come in pairs of fast OFF cells and biphasic OFF cells, which receive inputs from both the ON and OFF pathways, and the slow OFF and ON cells. It turns out that they have different spike latencies, which can be e a powerful mechanism to rapidly transmit a new visual scene. Moreover, certain neurons in visual cortex are exquisitely sensitive to the coincidence of spikes on their afferents (30), which is one possible readout mechanism for a latency code.

The autors conclude that it is conceivable that early aspects of sensory processing operate on the basis of the classification of spike latency patterns.

Promoting happiness

Last December I wrote a short post about a Science paper providing neurophysiological evidence for the importance of social comparison on reward processing in the human brain. The last print version of Science has a paper teaching us how we can be even happier.

Elizabeth W. Dunn and Lara B. Aknin of the University of British Columbia, Vancouver, BC, and Michael I. Norton of the Harvard Business School in Boston write in their paper Spending Money on Others Promotes Happiness that although much research has examined the effect of income on happiness, they suggest that how people spend their money may be at least as important as how much money they earn.

Specifically, they hypothesize that spending money on other people may have a more positive impact on happiness than spending money on oneself. Providing converging evidence for this hypothesis, they found that spending more of one's income on others predicted greater happiness both cross-sectionally (in a nationally representative survey study) and longitudinally (in a field study of windfall spending). Finally, participants who were randomly assigned to spend money on others experienced greater happiness than those assigned to spend money on themselves.

They conclude that given that people appear to overlook the benefits of prosocial spending, policy interventions that promote prosocial spending — encouraging people to invest income in others rather than in themselves — may be worthwhile in the service of translating increased national wealth into increased national happiness.

The United States Declaration of Independence already postulates a right to pursue happiness, and the IRS encourages charitable donations by allowing a generous tax deduction for them, so our Government has already made the correct policy interventions. Now, when I look at my bank transactions for March, I am convinced I must be the happiest person in the world!

Color Chart: Reinventing Color from 1950 to Today

Carinna Parraman wrote: "Check out the Internet version of the Color Chart exhibition at MOMA in NY, it is beautifully executed and certainly worth a visit."

Follow this link to MOMA to see what you can do with creativity, color, and Flash.

Blue citation from Carrie Mae Weems, Moody Blue Girl, 1988

Administrative note and color lawsuits

First an administrative note. Most feedback we get from you, our esteemed readers, is in the form of personal email. Only rarely are we able to generate sufficient controversy to spark a debate in the blog comment section, such as with Non-local realism, An On-Line Color Thesaurus, or yesterday's Revolutionary White Reflectance Standard for Metrology. Therefore, we are happy for every good comment we get. However, as you are aware our blog server is rather crafty, and it is difficult for us to find comments when you replace the post title with your own title. This summer HP will be upgrading to commercial blogging software and this blog will run smoother, hopefully even multilingually. In the meantime here is my answer to a comment on color lawsuits I was unable to locate.

IANAL (I am not a lawyer), so I cannot tell you how many colors the Constitution on the Laws thinks you are seeing or entitled to seeing. From a color science point of view, color does not exist in nature, it is an illusion that is elicited in our visual system.

Colorimetry is the art to predict an illusion from a physical measurement, hence what we do in color reproduction is to try to build models that allow us to make statistical predictions of this illusion. Our supreme authority is the Commission Internationale de l'Éclairage (CIE), which in Definition 845-02-18 defines (perceived) color as follows:

Attribute of a visual perception consisting of any combination of chromatic and achromatic content. This attribute can be described by chromatic color names such as yellow, orange, brown, red, pink, green, blue, purple, etc., or by achromatic color names such as white, gray, black, etc., and qualified by bright, dim, light, dark etc., or by combinations of such names

Perceived color depends on the spectral distribution of the color stimulus, on the size, shape, structure and surround of the stimulus area, on the state of adaptation of the observer’s visual system, and on the observer’s experience of the prevailing and similar situations of observation

Perceived color may appear in several modes of appearance. The names for various modes of appearance are intended to distinguish among qualitative and geometric differences of color perceptions

As all the et cœteras in the definition reveal, there is nothing that allows you to count how many colors you can see. A metric you could use is to enumerate all the color names you can tell, i.e., the size of your color lexicon. However, the color lexicon is acquired, so its cardinality depends on your experience. The cardinality also depends on time, as we name more colors the more evolved the civilization gets.

For example, 2000 years ago, the Romans could not distinguish between blue and green. More recently, 1000 years ago, the Japanese, which had three colors — white/pure (shiroi), black/dark (kuroi), and colorful/red (akai) — added a fourth color to their vocabulary because tree leaves, sky, and the sea are colorful but not red, hence aoi became the name for those things, without distinction between green and blue. Even today midori (green) is not an attribute but a substantive; the color of an unripe apple is blue (aoi), not green (midori) because it does not make sense from a grammatical point of view.

We can use psychophysics to start with one color, then change is slightly until we perceive a just noticeable difference (JND), increment the counter by one, and start over with the next iteration step. This way we could determine that we can see something between 6,000 and 10,000 different colors. But when you look what populations name distinctly in a color thesaurus, you typically find a 700 to 900 word dictionary.

If we go back to the lawsuit discussed in that blog comment, we could take the position of the electrical engineer and look at the addressable number of colors. When a display can address 16,777,216 colors, this is many more than you can actually see, and even 262,144 is much larger than 10,000. From a color science point of view, the point is moot.

Turning the argument around, a printer can only put down or not put down cyan, magenta, yellow, or black marks. Yet you would not claim the printer is capable of printing only four colors. The trick is that the human visual system (HVS) has a limited resolution and therefore you can halftone colors with dithers.

In display monitors and TV the spatial resolution is much lower than in printers, so instead of spatial dithering, temporal dithering is used, but you still see the same color, it was just cooked differently. Remember, color is just an illusion elicited in the HVS.

One complaint in that post is that you can see artifacts when you can address less than 16,777,216 colors. That is moot too. Give me any two colors on an 8 bit display capable of displaying only 256 colors and I can produce a completely smooth gradient between your two colors, with each step below one JND.

This is the HVS as we know it in color science. IANAL, and I do not know if the law refers to a human visual system. For that matter, I do not even know if lawyers might live in a world where the photons are colored.

To close the loop, if you have comments, do not send me email, post them to the blog without changing the title.