Fine art ink jet

The French magazine Réponses Photo just published its fifth special edition issue. It has a very interesting survey of ink jet printers for fine arts.

It starts on pages 39-39 with a brief overview. Then it presents the technologies and product line-ups by Epson, HP, and Canon. Interspersed is a glossary that elucidates terms like bronzing and metamerism.

After a section on papers, you will find a short article on creating black and white prints. After a question and answer section, Réponses Photo presents a series of interviews with gallery owners and curators.

This survey of ink jet printers for fine arts concludes on page 60 with a summary and discussion of the designation of prints. Réponses Photo recommends not to use the term digital print, as the original image can be AgX or digital, while a printer can be digital or laser on AgX. While in France — where Epson test marketed the first ink jet printers for fine arts, and therefore fine art ink jet prints have been around for many years — the term Digigraphie is common, Digigraphie it is not known in Anglo-Saxon countries. For example, in the US the French term of giclée is commonly used, while in France the same term is unknown in this context (the verb gicler means to spray ink on paper).

Réponses Photo recommends to write on the back of each print the ink type, paper, and printer model, which will help a future restoration if the print becomes valuable. For the nomenclature it recommends to at least distinguish between giclée pigmentaire and giclée dye.

It should go without saying that this survey is not a product test. Rather, it gives you the knowledge necessary to form your own buying decision depending on your artistic message.

The blue hour

In the Francophone world you often come across theatres and hotels named "l'heure bleue." When clocks are depicted in suggestive paintings, they are often set at the blue hour. When is the blue hour, and why is it important to painters and photographers?

The blue hour is at four o'clock in the morning, before the opulent and busy morning has started and many people still sleep. During the blue hour, when the night plays with dawn, light has a rare quality from the sky's cold blue and the star's warm yellow light, which bathe objects with two opponent illuminants. At this mesoptic illuminance level our visual system is tetrachromatic, with rods and cones all contributing to colors appearance.

In the Silicon Valley, the light pollution is so high, that this special time of the day cannot be appreciated, but for example in the Alps, nature is still pristine and nights are dark. I invite you to experience the blue hour, and even dawn, on top of a pristine mountain. Then, please, help fighting light pollution and turn off your lights when you sleep.

By the way, five and six o'clock are not colored, they are "l'aube" (dawn), and "le levé" (get up).

In reality, l'heure bleue, this quiet time of the day when nocturnal animals have already gone to sleep and diurnal animals are still sleeping, has a different meaning to artists. That perfumes have been named L'Heure Bleue is a hint. As Félix Vallotton's 1899 "La visite" shows, it is the time for lovers to say good bye, and the time on the alarm clock on the gentleman's night stand indicates the blue hour.

digital photo workflow for the rest of us

Recently a colleague a few cubicles down showed me some prints he did on his HP Photosmart Pro B9180. I was impressed with the image quality and I am wondering if time is ripe for the rest of us to switch from AgX to digital photography. You get your print in just 90 seconds and as Ingeborg Tastl's fade simulator illustrates, the permanence and durability is excellent.

Let me first explain what I mean with "the rest of us." In today's times of the transitioning organizations, the masses have become "transitioning consumers," obediently updating their gadgets every time a new release comes out. Besides the fact that for us researchers in transition such a strategy is not affordable, it is not meaningful from a quality point of view.

In fact, if you are not a commercial photographer, to win in competition you must be able to produce a gallery quality print in a reasonable amount of time. In my darkroom, I can crank out a 12x16 inch print every 10 minutes, including cropping and exposing a black frame to separate the photograph from the white frame. I am using an old Focomat and a Gossen exposure meter, so I do not need to focus nor make exposure trials.

This means that it is not only a pecuniary question but also a question to be skilled with the equipment. Developing implicit knowledge takes time and perseverance. Therefore, you cannot be a transitioning consumer but have to do it the old way by paradigm shifts or technology disruption.

For a long time I was shooting with a Nikon FM titanium and manual fixed focal length lenses. Then came the time my eyes had gotten sufficiently old that I was no longer able to focus instantaneously, so I had to make a paradigm shift to an F100 and a couple of autofocus lenses.

Today, digital cameras offer a substantial speed advantage over traditional cameras in that they use imaging technology to do quite a lot of processing from the time you press the release and the image is recorded. In fact, the cameras first sample an ambient light picture, then shoot one or two measurement flash bursts, compare the two images, and then compute the ideal exposure parameters and flash duration. All this takes place during the few milliseconds it takes to move up the mirror, a fraction of the time it takes the old way of controlling contrast with filters.

In summary, the printing technology and the camera technology are both ready for a paradigm shift. What I am not sure about is the workflow. As I stand now, a digital workflow is an order of magnitude slower than a wet chemistry workflow. Maybe you can tell me what I am doing wrong, so I will describe what I found out.

I downloaded a number of trial programs (fully functional software with a 30 day expiration date) and had to discover that little of it is practical.

Let me start with my hardware. For my tests I am using a D70 body I had around for producing legal documentation. My PC has a 667 MHz processor, 512 MB of RAM, and a 133 MHz bus, which are all sufficient for my day job as a researcher in computational color science.

Since today's sensors have a bit depth of 12 bits per pixel and today's LCD panels also have a bit depth of 12 bits per pixel, it does not make sense to use a JPEG workflow, which today requires retinexing the image down to 8 bits per pixel. Yes, ISO is adding a new layer to JPEG for high dynamic range (HDR) images and is considering JPEG XR, but they are not yet out and hence not implemented in any cameras.

Therefore, there is no other choice than using a "raw" workflow, in which the raw bits from the sensor are processed directly. Instead of raw file, the term "digital negative" is also used.

There is a number of quite powerful photo management programs for the consumer market. However, I quickly found out that when you throw at them a compact flash card full of raw images, they quickly choke and become unusable.

At the other end of the spectrum, professional photo management programs are unusable slow on my PC. It appears you need at least a quad-core, some 4 GB of RAM, and a 1.5 GHz bus — not everybody's kind of iron.

What I found to be usable is Nikon Transfer to download the images. The main advantages are that it completes the embedded XMP/IPTC metadata, renames the files to a systematic archival name, and automatically stores backup files on a second medium, which is more important than a conventional backup for my legal documentation images.

As you can see in the embedded EXIF metadata in the image below, this program has a bug in dealing with the date and time. During the transfer it did correctly update the clock in the camera, but is did not correct the time stamp in the EXIF data by the changed amount, which happens to be 8 hours because I forgot to reset the Daylight Saving Time and the offset from Universal Time Coordinates for my current location.

The next step in the workflow is to individualize the metadata, tag the images, organize them in folders, and then convert copies to JPEGs that can be thrown in a consumer level photo management program. Since I keep my negative in binders with their contact sheets, I also want contact sheets from my digital images, so I can keep them in a binder for quick browsing.

Since Adobe did a good job with XMP, I would like to have all the metadata in the image file, not in a separate database or in sidecar files. Essentially the software for this workflow step should just be a veneer over the operating system's native file system.

Adobe's Bridge is attractive, but it is designed for sharing files between Creative Suite programs and does not fit well in the workflow I have come up with so far.

Nikon's ViewNX is a better fit, but is has some quirks. For example, to convert the image for the above figure, when I specified the size for this blog's column width, it changed the size to 640x426 pixels. Also, the conversion to JPEG is so slow that I have to let it run as a batch job over night. However, organizing the images is very fast, because the program appears to use the preview image in the metadata instead of rendering the raw image.

Before the images are converted, there should be a step for manipulating them. For example, I like to apply an unsharp mask, do some minor local contrast manipulation, and correct inevitable optical distortions in some lenses. I tried to use Capture NX, but on my PC it is way to slow and the program also has a problem to allocate memory, because often the image becomes just a black rectangle.

At this point I am stopping, because I really would like to hear about your experience. What did you try? What are you happy with?

Colour: Design & Creativity

Form the AIC e-news, november 2007:

Colour: Design & Creativity, the new online journal from the Society of Dyers and Colourists (SDC), is intended to serve a gap in the marketplace by appealing to a multidisciplinary audience seeking a better understanding of colour and its application in design, theory and practice. In particular the journal will emphasise the synergy between colour and design, as opposed to their individual importance.

Comments editor, Prof. Stephen Westland, ‘Although design is for convenience recognised as a discrete discipline, it is truly multidisciplinary, involving aspects of science, technology, art, crafts and business. Design represents one of the significant interfaces between art and science, and the journal will be dedicated to exploring this interface.’

Among the topics covered in the inaugural issue are colour and emotions, analysis of colours in branding, design concepts using thermochromic colour change, colour forecasting and preference in the fashion industry, and an article that describes what the author calls ‘a new colour form’.

The journal will appeal to colourists, designers, scientists, artists and other professionals alike and seeks submissions of research related to colour: from explanatory papers, case studies and essays, to reviews of books, events, collections and installations. Being published online, a key feature will be the inclusion of ‘galleries’ of work, as well as material in movie and audio format. All articles will undergo a process of peer review, managed by the editor and assisted by a body of international experts forming an advisory panel.

In the first instance, Colour: Design & Creativity will be open access, thanks to funding received from the Worshipful Company of Dyers, and can be found at www.colour-journal.org. Anyone active in colour research, development and application is invited to submit material for subsequent issues, or to contact the editor, by emailing: editorial@sdc.org.uk.

Photo permanence and durability

Experience your memory fading away.

Historically, we humans have been willing to spend any amount of money on communication. We have been willing to spend even more money on communicating with our descendants after our passing — sky is the limit.

In the past you had to be a head of state to afford having your life cast in stone for posterity, or you had to be so good and work so hard that you would leave behind a historical legacy through the history books.

Today, everyone in our society can afford to leave behind their legacy in the form of digital items, such as scanned or digital photos, HD videos, AAC files, etc. Although such an archive is compact and convenient, it is still subject to bit rot. Actually, with the acceleration of technological progress, the span of time until bits have rotted is getting shorter.

With this in mind, there is still a strong argument for printing your memories and keep them around as atoms instead of bits. There is also a remarkable convenience to hard copies, especially when they are in the form of photo books.

Atoms can also rot, and in particular the dyes and pigments in inks fade. Therefore, it is useful to know how long your prints last. More specifically, you want to know how long prints on a specific media printed with a specific ink last.

In a concrete example, imagine you took a photograph during your honeymoon trip and you would like to be able to still enjoy at at you golden anniversary. Can you use refilled cartridges on generic paper or should you shell out money for fancy HP Vivera inks and special photo paper?

My colleague Ingeborg Tastl wanted to find a good answer just to this kind of problem — how will the photo with my memory fade away during the years? Since Ingeborg is our ICC profiling specialist, she built an interactive tool that allows you to simulate the fading of your memory when printed on two different ink and paper combinations. This is how the tool looks in on my PC:

Ingeborg being a very nice person, she lets you have her tool. You can download it from here and look at your own memory fading away. Of course, the lawyers had to have their say to keep us out of Court, so the selections are somewhat restricted, but it is still an interesting tool. For now the simulator is Windows only, but you can run in on an a virtual PC in an Unix system like a Mac.

An On-Line Color Thesaurus

Color names are a powerful means of selecting and communicating colors. There are a variety of color vocabularies and dictionaries available but there has been less work in capturing the similiarities and differences in color naming. This post is a tool post in that the online color thesarus is embedded directly in the post.

Getting Started
To use the online color thesaurus, click on the screen-shot below to get to the thesaurus page. There simply type the color name in the text field. Once you have typed in your color name click on "submit" and then the results will be displayed. You can use the "clear" button to clear the text field.



Results
The results that are returned are a large color square with a rendering of the color if it was found. If the name was not found, for example "greeb" was entered, then the next nearest color name in terms of edit distance, in this case "green", will be returned. So no you won't have to remember how to spell fuchsia.

In addition to the colored square are the corresponding RGB and hexadecimal values. Finally there is a note about how common the color name is. Below this are the color synonyms and antonyms. Each column has smaller color squares rendering the color names and the names with links so that you can easily click-through to these names. The results are based on analysis of 20,000+ color name database in English collected from a 20+ language ongoing online color naming experiment.

MPEG-21 blog

If you are interested in Multimedia Communication for Universal Media Access (UMA) and MPEG-21, you may want to keep an eye on Christian Timmerer's blog on Multimedia Communication. Christian has been involved in MPEG-21 from the beginning and is a very active expert in the committee.

If you do not know anything about MPEG-21, you may be interested in the notes of the course I gave at VCIP 2003. They are a bit dated, but after you go though them you can quickly get up to speed with the current status on Christian's blog.

See also my previous post on MPEG-A.

Software patents

Earlier today RocketRoo left a comment on my earlier post on A color scientist's role, but it really is a new thread because my post had nothing to do with patents, so I am answering with a new post. Here is the comment:

Regarding the role of patents, one of the 2007 Nobel laureates in economics, Eric Maskin (http://nobelprize.org/nobel_prizes/economics/laureates/2007/), also did research at MIT on the value of software patents. He determined that software was a market where innovations tended to be sequential, in that they were built closely on the work of predecessors, and innovators could take many different paths to the same goal. In such markets, he concluded, patents might serve as an innovation inhibitor rather than an innovation incubator. See http://www.researchoninnovation.org/patent.pdf

Personally, I have mixed feelings about patents. The original idea was for society to reward inventors for their contribution by allowing them the right to exclusively reap the commercial benefits of their invention. However, now the system is broken.

If there is a date to be set for when system broke, it is probably the day the patent for the intermittent wind-shield wipers was enforced. But in reality, the system got broken by the submarine patents.

Some submarine patents came into being innocently. As I wrote in the post on A scientist's role, discovery is in the air and the skill is in being the first to grasp them. An inventor's antenna can pick it up and he or she can intuitively reduce it practice and file for a patent before the rest of the pack does. But when this happens too far ahead of the bleeding edge, the discovery is not yet well defined in the ether and intuition plays a larger role. Because of this, it is very difficult for a disconnected outsider to appreciate the invention, especially when we no longer show up at the Patent Office with out physical prototype..

Patent examiners are in such a difficult position and it can take a lot of back and forth until the examiner is satisfied that all that implicit knowledge has been made explicit, and can grant the patent.

But then there are the slacker or parasites, known more scientifically as defectors, who when they detect a discovery in the air submit a vague patent application based on a hunch, without understanding the issue nor attempting to render it to practice. An outsider, such as an examiner, has no way to tell a defector from a cooperator, so they have to give the benefit of the doubt while at the same time pursuing due diligence.

In Japan, applications are laid open after six months and anybody can comment on the applications. The system is more fair, but comes at a high cost for the engineers who are forced to work through reams of applications every day for a few hours.

Here in the US a similar system is being studied and HP is one of the companies behind this effort. If you are very experienced, I may suggest you join this collaborative effort as a reviewer. Just go to the Peer-to-Patent site, enroll, and review those patent applications that are in your field of expertise.

So far for the ethical issues. Your comment was about software patents. One problem is that software patent applications have been allowed only since about 1989 (AT&T Bell Labs traveling salesman patent). By that time computer technology was as advanced in several research labs, as it is now in the commercial world. However, in these 30 years computer development has changed so much with the use of wizards and frameworks, that today's programmers have no knowledge of what was standard practice 30 years ago. Hence, the wheel keeps being reinvented.

So, shall we get rid of software patents? It depends. We had this discussion about five years ago in one of the Swiss National Science Foundation Review Panels. We came to the conclusion that an invention should be patented only if it is necessary to protect a new business venture. When this protection is not necessary, then the funding should be invested in new engineering, not in patenting, because they cost more or less the same and in the long term engineering is better for society.

This also leads to agile companies that must innovate faster than the competition can catch up with copying. The Swiss have recognized this as a competitive advantage of their industry.

Color space dimensionality

Today RocketRoo posted a comment to my short August post on a paper on Multiscale contrast enhancement. Since that is a few months ago, I will reply with a new post. Here is the comment:

Re: Multiscale contrast: achromatic dims

In this recent study, http://compbiol.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pcbi.0030179, Vladusich, Lucassen and Cornelissen provide evidence that brightness and darkness form the dimensions of a two-dimensional achromatic color space. This color space may play a role in the representation of object surfaces viewed against natural backgrounds, which simultaneously induce both brightness and darkness signals. The 2-D model generalizes to the chromatic dimensions of color perception, indicating that redness and greenness (blueness and yellowness) also form perceptual dimensions. Collectively, these findings suggest that human color space is composed of six dimensions, rather than the conventional three.

Posted by RocketRoo on 10/22/2007 11:45 AM

Let me first admit that I just read the first few paragraphs and not the complete article cited.

I am in violent disagreement with the authors. The opponent color model was first proposed by Leonardo da Vinci, (see chapters CLX and CLXII of his Trattato della Pittura, Langlois, Paris, 2^nd edition, 1701) then discussed by Wolfgang Goethe (see also here) in his virtual diatribe with Isaac Newton. The first modern theory of color opponency was proposed in 1872 by Ewald Hering and was very hotly debated until G.E. Müller and Erwin Schrödinger reconciled Helmholtz's and Hering's theories in the zone theory of color vision, which they based on the 1904 law of coefficients proposed by Johannes A. von Kries.

The matter was finally settled in 1956 when Gunnar Svaetichin was able to record from horizontal fish retinas and show opponent response in red-green and yellow-blue potentials. At the time, he showed that each horizontal cell is presumed to inhibit either its bipolar cells or the receptors, with further processing occurring in the amacrine cells and in the retinal ganglion cells.

You an always postulate a mathematical model approximating some phenomenon, but at the end what counts is physics and you cannot contradict the physiology on which color vision is based.

What may be confusing the authors is that much of color science is for aperture color. If the appearance mode is different, then part of ordinary colorimetry falls apart. This is why there are color appearance models and the authors should have based their work on these.

Hue Angles blog

The ISCC (Inter-Society Color Council) now has a blog, which allows color scientists to interact on articles published in the Hue Angles column of the ISCC Newlsletter. Here is how its editor Dr. Michael H. Brill of Dataclor descibes this new blog, whose name is Hue Angles:

In fall 2006, Hue Angles began as a column for the ISCC News, devoted to tidbits of interesting lore shared by ISCC members in short-essay form. In its first year, the topics spanned color in wetland preservation, spinning disks under colored lights, personal recollections of selling color-matching systems, green in the fashion industry, how to measure color using a beer cooler, and color contextual effects. Almost any color-related topic is fair game. As of fall 2007, Hue Angles is also being posted here to facilitate lively discussion. As always, you can submit ideas or contributions for the column itself to Michael H. Brill, mbrill@datacolor.com.

Prof. Osvaldo da Pos, University of Padua, Italy contributed the first post, which is on colors and contectual effects.