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.
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:
Next time you purchase a printer, please consider one of our sponsor's fine printers: http://h10010.www1.hp.com/wwpc/us/en/sm/WF02a/18972-18972-3328065.html
The Midterm Meeting of the International Colour Association (AIC) at the Zurich University of the Arts is in full swing. Here are some pictures from the reception:
In the last couple of months I had been writing about the problem of selecting color palettes that are visually pleasing. I started with Mik Lamming's effort in bringing back to the office the colors that were sacrificed with the transition from mimeographs to Xerox copiers and from color-ribbon typewriters to IBM Selectrics. After a digression on the appearance of flamingos, I continued with the problem of selecting colors for VLSI design and illustration, showing the Meta-Palette and a set of other color selection tools.
Today I will step back a little and present a broader view. The problem of designing pleasing or harmonious palettes is as old as visual communication. In western culture a quantum leap occurred with Leonardo da Vinci's prolific work on color analysis and structure (leading to chiaroscuro), which continued with Michel Eugène Chevreul's simultaneous contrast (leading to Impressionism), and with Georges Vantongerloo's attempt to mathematically represent color palettes (leading to De Stijl and Bauhaus).
Essentially the Proto-Palette was just an evolution of this thread, made by a guy sitting in his office and talking to media designers. The fire test came around 1989, when it was decided that GlobalView's desktop would be in color. It turned out that the Proto-Palette tool (color harmony) was too regimented and the Digital Palette tool (palette database and color blending) needed a flexible user interface, so I integrated these tools, along with the earlier Meta-Palette and Maureen Stone's Color Tool.
This integrated set of tools allowed designers to start with a palette—for example, complexion—and add a contrasting color or changing a color lexically by adding a modifier like "muted." Codeveloping the color selection tools with the GlobalView GUI, all while the designers where working on the desktop (icons, etc.) proved to be very fruitful and efficient, leading to a paper at SPSE's 43rd Annual Conference (now IS&T). Since I had a full implementation, I gave a demo at the end of my presentation:
These tools were not the only game in town. At Tektronix, Jerry Murch and Joann Taylor were doing similar work. In Japan, Shigenobu Kobayashi had developed a system based on his Color Image Scale:
All this came together around 1993 with the release of Canon's Color Advisor, described in L. Lavendel and T. Kohler: The Story of a Color Advisor. In S. Sü̈sstrunk and A. Lakatos, editors, Sixth Color Imaging Conference: Color Science, Systems and Applications, volume 6, pages 228–229, Scottsdale (Arizona), November 1998.
As they describe in their paper, Larry Lavendel and Tim Kohler actually surveyed their potential users, instead of just working with a few designers like I did. This allowed them to take into account the semantic aspects and thus create a tool that is easy to use by anybody, as opposed to my tools, which were usable only by designers and researchers.
It is a pity, the Canon Color Advisor did not survive in the market, because nothing better was produced after it and it looks like with their Canon Color Agent, Larry and Tim were up to something even much more powerful.
In retrospect, Canon's Color Advisor was just too far ahead of time. When in 1991 Canon implemented their device independent color management system, they tried hard to fully integrate it into Windows. When Microsoft refused to cooperate, Canon's CEO Dr. Yamaji flew to Seattle to negotiate directly with Bill Gates.
Unfortunately the latter declared that Windows users will never create color documents, and all that was needed in Windows was a fixed palette of 16 colors for the GUI, with none required for documents. When Dr. Yamaji insisted, Gates declared that color would require an additional floppy disk in the upcoming release of Windows 3.1, and at 15 million copies to be sold, the cost for enabling managed color documents would be the astronomical sum of $15 millions.
Unfortunately this forced Canon to bury its Color Advisor in the printer driver for a post-processing step, instead of making it available during document creation. However, it did save Microsoft $15 millions, and I am sure they made good use of it.
All this is old history. The notion of artists, designers, and scientists designing color palette selection tools is a concept of the second millennium. In this millennium, the process consists in crowd-sourcing large data corpora and using analytics to make inferences. The questions then are:
Friday, January 28, 2011 we wrote about our EI papers, but then Saturday, February 19, 2011 we had to backpedal on the accessibility of the papers. Today we are happy to announce that with the generous support of our lab director who is sponsoring the page charges, we are able to make the fuchsia paper open access.
Colors are often named ad hoc, like in the image above. In the fuchsia paper, we derive the correct method to elicit color terms. In a second part, we report on the calibrated lunch experiment, where we show that color terms elicited from emissive samples like those from crowd-sourcing correlate very well with those elicited from reflection samples like those used in the World Color Survey.
Here is the link to the paper: http://dx.doi.org/10.1117/12.872581 (the button to download the PDF is on the right). The slides are still in the post of Tuesday, January 25, 2011.
Happy Easter and happy reading!
Last December First, I wrote about the story behind the data glyph technology and the preservation of digital images (here is the link). As it happens, at the Electronic Imaging Symposium two weeks ago, two papers presented recent progress on this technology.
Gaurav Sharma's presentation disclosed an extension of Tom Holladay's rotated dots from grayscale to full color. The authors were particularly concerned about the æsthetic quality of the images with the added payload. They conclude in their paper:
In this paper, we present a high capacity image barcode scheme for applications that require both high capacity and pleasing visual appearance of the encoded region. The scheme combines orientation modulation based data encoding on per-channel basis and color separation. We demonstrate that significant performance improvements can be obtained in terms of embedding rates by sacrificing image fidelity in favor of embedding robustness. Our simulation and experimental results indicate that dot orientation modulation based data embedding can achieve high embedding rates and well suited for per-colorant channel based data encoding in printed documents.
Link to the paper: http://dx.doi.org/10.1117/12.872215. Citation: Orhan Bulan, Basak Oztan and Gaurav Sharma, "High capacity image barcodes using color separability", Proc. SPIE 7866, 78660N (2011); doi:10.1117/12.872215.
Robert Ulichney's presentation described a system specifically for solving the image bit rot problem. The method presented was grayscale, so the payload would not be in the image's halftoning, but in a logo or other monochrome ornamental artifact.
The novelty is that the halftoning method is not Tom Holladay's rotated dots but a new algorithm called stegatones. Compared to the rotated dots, which allow a binary code, stegatones consist of 1-bit to 3-bit carriers, thus allowing a much higher capacity payload. The authors conclude:
We have improved on the scheme reported earlier for hardcopy image backup by embedding metadata into a steganographic halftone object. The advantages of this approach are:
- a better æsthetic presentation of the photo archive
- the elimination of the need to solve the complex OCR problem
- a more compact representation of the color tiles and metadata
- a layout for which auto-alignment is easier and thus the data is more recoverable
Building on the original motivation to use an analog hardcopy means of long-term image storage, our solution transcends hardware obsolescence by requiring any means of scanning the data coupled with the recovery software. While we can predict that hardware for reading digital storage media will likely not be available decades from now, some means of hardcopy scanning will be. So our strategy shifts the need to archive recovery hardware, to archiving recovery software. Long term recovery then depends on the availability of generic source code that includes means to read the accompanying stegatone.
Unfortunately the authors do not address the requirement to preserve a system capable of running the recovery software, so we are still stuck in the PhotoCD problem.
Link to the paper: http://dx.doi.org/10.1117/12.872612. Citation: Robert Ulichney, Ingeborg Tastl and Eric Hoarau, "Analog image backup with steganographic halftones", Proc. SPIE 7866, 78661I (2011); doi:10.1117/12.872612
If you missed the conference, you can easily read the two papers after downloading them from the two links above. However, you would have missed the conversation in the hall after Ulichney's talk. Actually, Elvis had already left the building, when a conversation started with Reiner E. from Rochester and Keith K. from Kihei.
We were wondering how far back this and the related technologies go. Reiner now has the date: 1982. During his first visit to the DGaO Conference (Deutsche Gesellschaft für angewandte Optik e.V.) he was getting a 'free ride' for operating the slide projector.
The talk contained the following: since digital storage is too expensive and cumbersome :-) and since it is always better to store in human readable form, since all other forms will disappear over time: create a system that stores digital in a human readable format. Data was from some satellite images (or other high quality imaging system).
Each data pixel (M > N bit) was converted to a N bit signal, where the N bits will be used as human readable signal and directly converted into an 'explicit' halftone. Meaning each pixel will get its own halftone cell with the corresponding number of elements set to "on". Since M > N, we have a many-to-one map and thus will create an M bit lookup-table for the explicit halftones, where the Mi,j that map to Ni have the identical number of 'on' bits, but in different spatial arrangement. Such a system was known in the digital field, but Reiner is not sure about the name. It is a less than optimal system for information density.
The SPIE/IS&T Electronic Imaging Symposium is over and being wrapped up. The event was successful and the increased attendance is a positive signal of the improving economy. The quality of the papers was generally high and the technical discussions in the corridors were intense, letting us hope for good papers being incubated from this synergistic interactions and being presented at EI 2012 in the same location 22–26 January.
Our papers were very well received. We received many questions on our paper "Is it turquoise + fuchsia = purple or is it turquoise + fuchsia = blue?", which was generally referred to as "the calibrated lunch paper." The paper is now available online at this permalink: http://dx.doi.org/10.1117/12.872581.
This year's traditional session on the Dark Side of Color will forever be remembered for Dr. Gabriel Marcu interrupting the presentation as Dr. Bob Ulichney was sneaking out of the room and announcing "Dr. Ulichney has left the building" in reference to Elvis.
Our paper for the session on the Dark Side of Color was more about being in the dark on color. The title "ICC profiles: are we better off without them?" is of course very controversial, but when the consequences are in the billions of dollars, the gloves are off and print service providers (PSP) will do what they have to do. In the hallways, this paper was referred to by a comment made in the Q&A period: "is it legal to profile ICC profiles?" The paper is now available online at this permalink: http://dx.doi.org/10.1117/12.880240.
I hope next year we can counter this question with plenty of detailed information. One thing though will be sure: the committee dinner will be again at Sakae.
In ten minutes we are presenting our provocative paper on ICC profiles in the session on the Dark Side of Color in the Harbour Room A here at EI. In case you did not make it, here are our slides:
In five minutes we are presenting our paper on arithmetic with color terms in the Harbour Room A here at EI. In case you did not make it, here are our slides:
Here are the speaker's notes:
{Color diagrams by scientists}
When color scientists draw chromaticity diagrams to illustrate their publications, they do it in black and white. Color, at most, is used for annotation purposes, not as self-reference.
{Color diagrams by designers}
This frustrates color designers, who make ample use of colors and expect more guidance from color scientists using the designer's language. Therefore, they prefer colorized chromaticity diagrams and they like how they can pencil in color theories because chromaticity diagrams can be used to predict the mixture of aperture color.
However, when they explain color theories using color terms, they get confused, because they have samples for the basic color terms and use them to label the colorized chromaticity diagram.
{sRGB color diagram}
In fact, the colorization of chromaticity diagrams is just that: a colorization. It bears little relation to the color's self-reference, because there is not device gamut covering the entire chromaticity diagram.
This figure shows how a chromaticity diagram can be more accurately colorized on an sRGB device.
{It is 3-dimensional!}
In the yellow range, the colorization fails and sticks out of the chromaticity diagram. This is because the gamut is tridimensional and the gamut rendering algorithm is somewhat imprecise. On the right side we move the viewpoint.
{Printer gamut}
You are seeing the projected image from a beamer, which in reality is not an sRGB device, so right now you are not seeing the correct self-referenced colors. In the case of a printer the error is even larger, but if for a moment you imagine viewing the diagram at right on a SWOP printer, you realized how off the colorized chromaticity diagram we saw earlier is.
{Color theories — an abstraction}
From a color science point of view, the various color theories have their own problems. Compare for example Leonardo's color circle with that proposed by Itten. The color are quite different. What happened?
{Itten revealed}
Of Leonardo we know that he considered color to be a perceived entity and his theory is based on color opponency. We discover Itten's method by looking at the black and white version of the color circle published in the student version of his book: He simply started with monolexemic color names and then interpolated with bilexemic color names to obtain a richer circle.
{Color by measurement}
We conclude, that we cannot predict arbitrary color mixtures by doing arithmetic with color terms obtained from colorized chromaticity diagrams. The general way to predict color mixtures is to reproduce actual samples and then measure them.
{Naming color}
How then can we determine the proper color terms? The World Color Survey has shown how to do it for the colors on the surface of the Munsell color gamut, and Boynton and Olson have shown how to do it for the full OSA color gamut.
Both experiment classes are limited to the basic color terms. For a large number of color terms, we need data from thousands of observers, which we can hardly do using controlled psychophysics techniques. Possible approaches include Amazon's Mechanical Turk and open Web surveys based on crowd-sourcing.
{Validating crowd-sourcing}
Unfortunately, non-withstanding Boynton's positive assessment of the uncontrolled protocol used in the World Color Survey, crowd-sourcing is still considered very controversial in the color science community. Therefore, we decided to perform a controlled experiment with an unusually large number of observers.
{Color chips given and color seating arrangement}
We printed a number of color chips and gave them to the researchers having lunch at the cafeteria and asked them to sit at the labelled tables with the term closest to their color chip.
{Calibrated lunch vs. Web color centroids}
As you can see from this diagram, we achieved excellent correlation between the controlled lunch room experiment and the uncontrolled crowd-sourced experiment on the Web. Thus, our data from the Web is scientifically valid.
{Beyond crowd-sourcing}
One question arising when teaching color design is which synonym to use for a given color. To answer this question we need more data than even crowd-sourcing can provide. Also, we have repeatedly written how color terms are ephemeral and change with time.
In this diagram we used Google's English book corpus and tracked the number times fuchsia and magenta appear in book each year from 1800 to 2000. The appearance of the term magenta coincides with the historical facts and the numbers suggest your should prefer the term magenta over fuchsia.
{What is the best term for RGB = (0, 1, 1)?}
This diagram illustrates how cyan is not a good choice and you should use the term turquoise instead.
{Is the term for RGB = (1, 1, 0) monolexemic?}
We can use this approach also to answer very difficult questions, like the number of basic color terms. This diagram illustrates that olive green might be becoming a basic term also in English, because chartreuse is monolexemic.
Our data shows that few people ever learned to correctly spell fuchsia, but the data shows this is not critical. However, you should definitely learn how to spell chartreuse.
In a few days, imaging technologists from around the world will be flocking to the San Francisco Airport Hyatt to attend the Electronic Imaging Symposium.
Monday 24 January from 10:40 AM to 11:10 AM many delegates will fasten their seat-belts in Sandpebble Room D, where IS&T Fellow and HP Labs Director and Distinguished Technologist Dr. Steven J. Simske will be giving his Invited Talk on Parallel Processing Considerations for Image Recognition Tasks in the Conference on Parallel Processing for Imaging Applications.
Many image recognition tasks are well-suited to parallel processing. The most obvious example is that many imaging tasks require the analysis of multiple images. From this standpoint, then, parallel processing need be no more complicated than assigning individual images to individual processors. However, there are three less trivial categories of parallel processing that will be considered in this paper: parallel processing (1) by task; (2) by image region; and (3) by meta-algorithm.
Parallel processing by task allows the assignment of multiple workflows—as diverse as optical character recognition [OCR], document classification and barcode reading—to parallel pipelines. This can substantially decrease time to completion for the document tasks. For this approach, each parallel pipeline is generally performing a different task. Parallel processing by image region allows a larger imaging task to be sub-divided into a set of parallel pipelines, each performing the same task but on a different data set. This type of image analysis is readily addressed by a map-reduce approach. Examples include document skew detection and multiple face detection and tracking. Finally, parallel processing by meta-algorithm allows different algorithms to be deployed on the same image simultaneously. This approach may result in improved accuracy.
Useful links:
Technology allows everybody to do their own work without assistance. When office automation software programs allowed office workers to create professional quality documents, graphic artists had to take the sophistication of high-concept design up to the next level, above the abilities of office tools.
One of the key techniques has been the heavy usage of transparency. Consequently, commercial printers see a large number of documents containing transparency. The specification of transparency in PDF is very sophisticated, well above to the simple transparency used for example in video games.
Therefore, adding transparency to a GPU-based RIP is quite a challenging task. Indeed, not only has the complex PDF transparency to be implemented, but it also necessary to implement an ICC color management module on the GPU. And it all has to work on tiled images.
At the Electronic Imaging Symposium, John Ludd Recker from HP Labs will report on his experience implementing GPU-based transparency in Ghostscript. His lecture on A GPU accelerated PDF transparency engine will be in the Conference on Parallel Processing for Imaging Applications.
Useful links:
From the earliest days of digital color reproduction, there has been a need to add vector processing units to achieve viable executions times. For many imaging operations, algorithms can easily be vectorized because they operate independently on the pixels. However, some operations are spatial: sharpening, compression, error diffusion halftoning, etc.
In the last decade, the computing industry has undergone a major revolution: software from suites to apps and hardware from workstations to mobile devices. The hardware platform of choice is no longer a souped up high clock-rate server class microprocessor but a system on a chip (SoC) combining a CPU, GPU, memory controller, etc., all running at very low power. The challenge is then how to partition a computation between CPU and GPU, which is done at runtime through an OpenCL kernel. This kernel is very difficult to write, because today it is based on arcane heuristics, not on an algorithm based on the system's current state.
At the Electronic Imaging Symposium, Dr. I-Jong Lin from HP Labs will present a new theory to solve this problem. His lecture on GPU-Completeness: Theory and Implications will be in the Conference on Parallel Processing for Imaging Applications. In a nutshell, when an algorithm is transformed from serial to parallel, there is a loss of accuracy. When the accuracy vs. parallelism trade-off is exponential rather than polynomial, the problem belongs in the class of GPU-Completeness.
The algorithmic class of GPU-Completeness is defined in terms of input, output, parallel performance, and a quality metric. Dr. Lin will validate his theory with experimental data from imaging applications: color transformation, halftoning, and run length encoding.
Useful links:
Today is the last day to save $100 over onsite pricing for the Electronic Imaging symposium registration.
Next year's session on the dark side of color in the Color Imaging XVI conference at EI has attracted what the French call la crème de la crème in color imaging:
X-mas is coming up and it is time to shop for gifts. While tycoons of the financial industry like to splurge in Swiss tourbillons for $400,000 a piece, here in the Silicon Valley the Christmas bonuses are a little more modest. We were looking at the Leica M9 Neiman Marcus Edition Camera, his and hers just $35,000 for the pair. Nathan suggested that the cost might be in hand carving those 18 million pixels, but I think matching ostrich leather trim to the ostrich leather strap might be a larger cost factor.
The due date for the IS&T / SPIE Electronic Imaging Symposium is coming up 28 June 2010.
Imaging is pervasive in the human experience, be it through photographs that we take in our everyday lives to those that are used in space exploration, medical imaging, entertainment, science, or security. Electronic Imaging 2011 is the one international conference where papers on all aspects of electronic imaging are presented, and where you can develop both your career and business by networking with leading researchers and entrepreneurs in the field.
New for EI 2011 is the conference on Parallel Processing for Imaging Applications, chaired by John D. Owens, Univ. of California, Davis; I-Jong Lin, Hewlett-Packard Labs.; Yu-Jin Zhang, Tsinghua Univ. (China).
Dr. I-Jong Lin explains, "with all the changes in computer architecture and networked systems, I think this conference has a tremendous and timely opportunity to give serious insight how optimization of computer architecture can lead a greater understanding of how we represent and perceive the world."
Prof. John Owens of UC Davis adds, "we would be delighted to have a wide range of submissions for a high-quality program and hope you will help us with this goal."
Due Dates: Abstract (500 words) and Summary (200 words): 28 June 2010
Manuscript for On-site Proceedings: 15 November 2010
For more information see http://tinyurl.com/ei111ppia
When we think about places we have never visited, we build on other information about the place—the stereotypes—we have gained from variou...
