Friday, September 24, 2010

PARC's 40th anniversary

Yesterday, PARC celebrated its 40th anniversary. The first part consisted of three panel discussions in the auditorium, which was packed full. The average age was relatively high, as mostly people from PARC's first two decades showed up, several from very far away. The air was electric, but this is no surprise with most of the leaders who created the technology that made the Silicon Valley all in the same room.

For the second part of the celebration we walked up to the third floor for a reception and technology showcase. On the way, it was refreshing to see that unlike us, PARC still has a cafeteria and a technical information center. But most satisfying was that talking with the current employees it is clear that PARC still has its secret sauce. They are the best scientists in the world, fired up to invent the future. When they explain their research you can feel how excited they are, and in their interactions you can experience the deep level of mutual esteem for each other: they each contribute their particular knowledge to the team, in an amalgam of synergy. Quite unique.

Happy birthday PARC, still rocking like 40 years ago!

Tuesday, September 21, 2010

Movie Uses 3D Printer

Watch the adventures of Dot.
Animators used a 3D printer to make 50 different versions of Dot, because she is too small to manipulate or bend like they would other stop-motion animation characters. The figurine’s tiny features stretched the limit of the printer — any smaller and it would be hard to make distinct limbs. Each one was hand-painted by artists looking through a microscope. [ Source: Popular Science ]

Mirror, mirror off the wall ...

A previously unknown stranger-in-the-mirror illusion has been described. According to this 2-page academic paper, under the right lighting conditions, the participant just has to gaze at his or her reflected face within the mirror and usually “after less than a minute, the observer began to perceive the strange-face illusion”.

Unfortunately, the intriguing citation for "Margaret Thatcher: a new illusion," Perception 9, 483 – 484 1980, is restricted.

Caveat lector: I haven't tried it personally but as far as I know, this is not a hoax.

Journal impact factors

I had not realized I had not posted for quite a while the impact factors for the journals of interest to our readers, so here it is:

Monday, September 20, 2010

Ethics of bit rot

I am finishing up a conference paper and was planning to add some old photographs to document a workflow. I had several computers since I took the photographs, and because I have my stuff on several external disks (we researchers in image processing keep running out of disk space), I was not able to find them right away.

I remembered the photographs had been taken on film, so I thought can just quickly retrieve them from my PhotoPD archive. In fact, there they were, on PhotoCD number 6232 3073 2355. Lucky me.

Saturday, September 18, 2010

Leonardo da Vinci: The Audubon of Automata

I was asked to review Leonardo's Legacy: How Da Vinci Reinvented the World by Stefan Klein for the New York Journal of Books. My copy from the publisher (Da Capo, April 27, 2010) arrived very late and I only found time to complete my review last week. As a consequence, NYJB ended up inserting it retroactively into their April slot and they either dropped or did not know how to accommodate the timeline I created for my review. So, I'm including it here.
It is intended to give some perspective on the extraordinarily early period in which Leonardo lived relative to other well-known contributors to the development of western scientific thought.

Other themes covered in my review include:
  • Dissecting cadavers
  • Backward writing
  • Stroboscopic vision
  • The opportunist
  • Optics
  • Electric water
  • Innumeracy
  • Computing engines
  • Simulations
  • The grounded aeronaut
This is not the Leonardo you might have learnt about in school.

Friday, September 17, 2010

on the lighter side

A smile for the weekend: Mr. P. and Mr. H. test an instrument to deal with executives who have governance issues.

Mr. P. and Mr. H. test an instrument to deal with executives who have governance issues

Thursday, September 16, 2010

Tunnel Creek

Two days ago Intel announced the E600 system-on-chip (SoC), also known as Tunnel Creek. Intel positions it for in-car infotainment systems, Internet phones, and smart grid devices, but there are good reasons color scientists working on commercial printers should be interested in it.

A system based on an E6xx SoC

The figure above shows a possible system built around an E600 SoC, which is the dark blue part in the top center. The chip includes an Atom core running at 1.6 GHz (E680 part), a GPU running at 400 MHz, and a PCIe interface, drawing only 3.9W of power. The core supports hyper-threading, while the GPU supports OpenGL 2.1; the limitation is that memory is supported only up to 2 GB.

Hyper-threading means that two pages can be ripped concurrently for almost twice the speed, since ripping spends a lot of time on waiting for memory. Not shown in Intel's diagram is that the GPU interfaces to the CPU through the L3 cache. This should give a good speed bump when the rendered page is written back to the CPU for compression.

Two possible architectures spring to mind. The first is to use the system configuration in Intel's diagram above and use their Platform Controller Hub to interface gigabit Ethernet and a disk. The second is a bit more pushed.

Since the E600 has a PCIe interface, a custom hub could be designed, supporting 8 (this is a magic number) E600s, a gigabit Ethernet MAC, a RAID, and the digital press. The RIP would run in parallel using mapReduce, ripping 16 pages concurrently. This would deliver quite a power package costing only about $1000 in volume and drawing less than 100W of power!

And you could put all this on a blade, fill a rack, an use again mapReduce. Will this be a paradigm shift leveraging GPU-based ripping?

Monday, September 13, 2010

Color name boundaries

Papers on the World Color Survey often contain diagrams of the boundaries of the regions where the color patches are labeled with the same basic color term. The dream is to be able to somehow find the boundaries analytically, and for a much larger number of color categories than the 11 basic color terms.

Tsuei-Ju Hsieh and I-Ping Chen of the Chiao-Tung University in Taiwan might be onto something by serendipity. Their original intent was to assess the effect of size on color appearance, as reported in their paper Colour Appearance Shifts in Two Different-Sized Viewing Conditions. To sample a color space, they chose Alvy Ray Smith's old HSV color space that was used in the early days of computer graphics. They varied H in 30º increments starting from 15º and kept S fixed at 70 and V at 75, obtaining the following samples plotted in the x-y chromaticity diagram:

stimuli plotted in x-y chromaticity diagram

The figure is a little hard to read, but they label the colors as follows:

reddish orange
greenish yellow
yellowish green
deep blue
purplish pink

Then their perform their color matching experiments and consider the errors in CIE DE2000 and use the CIECAM02 color appearance model to study the errors in the perceptual correlates.

Here we are interested in ∆H, the difference in CIECAM02 hue quadrature. Plotting ∆H for the 12 hues gives the following plot, where HB is for "color samples arranged along hue and brightness axes" and HSL is for "color samples arranged for hue and saturation"; the L postfix is for "large target."

modulation pattern of ∆H using large targets as baseline

The red curves are the sinusoidal fitting of the data. The authors write:

The fitting results exhibit a certain regularity of hue shifts in different conditions across the hue circle. In all histograms, the rise and fall of bars alternate in a rhythmic manner, discounting the slight phase shift that occurred when different baselines were used. The zero-crossing points correspond to hues that their neighbouring colours are converging toward.

and conclude:

In the large size conditions the hues around the hue circle are apparently drawn in groups to some anchoring colours, i.e., a typical representation colour within the hue group. We propose that this phenomenon might be due to some kind of categorical perception of colours, a hypothesis that calls for future studies to verify.

Sunday, September 12, 2010

Mixing powders

A big part of job security for color scientists is that the mixture of colorants is very difficult to predict. This is especially so in color printing with CMYK halftones. It is surprising to learn that this is not so for mixed powders: their color appearance turns out to be easy to predict.

Thursday, September 2, 2010

Reduced Service

This weekend our blog has reduced service due to the installation of new power service. Between 2 p.m. Friday 10 September and 11 a.m. Monday 13 September (Pacific time, UTC+9), first access will be slow and there will be no images nor active posts.