Publications

The perception of 3-D shape from shadows cast onto curved surfaces

Wed, 11 Feb 2009 16:21:47 -0500

Norman, JF, Lee, Y, Phillips, F, Norman, HF, Jennings, LR & McBride, TR. (2009). The perception of 3-D shape from shadows cast onto curved surfaces. Acta Psychologica, To Appear.

A clever paper spearheaded by Farley. Shadows behave quite strangely in ‘reality’ but ecologically we’re hardly ever deceived by them — they rarely seem distorted. Here we show that we’re able to ‘undo’ the distortion created by the ‘cast-upon’ surface.

My primary contribution was the computational model that accounts pretty well for the observers’ behavior. Basically an affine model based on the ‘feature’ work we did previously (and shown here).

This also gave me the opportunity to co-opt nearly the entire campus’ big (well, OK, bigger than a breadbox) iron using the Mathematica Parallel Computing Toolkit. We wrote all sorts of crazy machine scavengers, load balancers, &c so as not to disturb the normal uses of the machines during the day. The last time I did something like this was the great ‘distributed laser printer project’ back at Pixar. Pete Docter’s student academy award film got lost on the way to the colorists and so we had the film digitized and printed out each frame using the entirety of Pixar’s laser printers. We set it up to start at around 10pm each night and Pete would come in at about 6am to ‘reap’ the harvest. It took two weeks. I don’t think anyone ever knew why their toner was disappearing.

Anyway, Wolfram Research wrote up a little ditty about the Mathematica use here.

Enjoy the sweet PDF goodness — NormanEtAl2009.pdf

Distortions of posterior visual space

Wed, 11 Feb 2009 15:55:39 -0500

Phillips, F & Voshell, MG (2008). Distortions of posterior visual space. Perception, to appear.

This was work Martin and I did back in 2001. We were curious about the representation of space behind the observer. Turns out, as always, Fred Attneave had already done something similar, now we had the tools to actually test it metrically.

Short take away story, you tend to ‘mislocate’ objects behind you with a bias toward the side of your midline the object is on. If there is an object behind you, to your right, you see it as being at an angle less than it actually is. It seems to be rotated toward your front.

This work was motivated by one of the author’s rowing experiences wherein pointing a boat becomes an interesting exercise in navigation.

This paper has a followup that does the same experiments only in motion. We’re in the middle of it, if you’d like to see it before it’s done drop me an email.

Download the preprint of the PDF here — PhillipsVoshell2009.pdf

(Note please that this link will go away once Perception gets in onto their preprint site.)

Deceptive Biological Motion

Mon, 5 Jan 2009 12:16:16 -0500

Natter, M., & Phillips, F. (2008). The french drop sleight: Deceptive biological motion [Abstract]. Journal of Vision, 8(6):1052, 1052a, http://journalofvision.org/8/6/1052/, doi:10.1167/8.6.1052.

Mike’s thesis was on the French Drop Sleight. Back in 1993 or so, during a visit to Columbus, Teller and I were having a brunch and he showed me this classic trick. We pondered some of the mechanical, social, and visual cues/deceptions involved in its successful execution and I mentioned that I’d get around to doing the experiments some day.

15 years later...

Mike was a student in my perception class a few years ago where he was able to con a good percentage of the class at three-card Monte, so he seemed like a natural fit to do the experiments. We did a variety of measures - attention, spatial, and electromyographic, and found some interesting things - most notably that the idea of ‘stress transfer’ (mimicking the muscular events that would happen if you actually transferred the coin) are important in the illusion’s success.

A paper is pending... we’re working on it. Until then here’s a link to the poster:
NatterPhillips2008.pdf

Crossmodal information for visual and haptic discrimination

Sat, 20 Dec 2008 20:45:01 -0500

Phillips, F, Egan, EJL (2009). Crossmodal information for visual and haptic discrimination. SPIE Human Vision and Electronic Imaging XIV. 7240-70.

This is an extension to Farley’s work on haptic-vision interaction. Think the Molyneux problem with more sophisticated analysis.

This was a bit of a tour de force, technology wise — a 3D printer (thanks Luc!) a 3D scanner, some Plasticine, and athlete’s foot powder. We presented some of this at VSS ’08.

Download the PDF here — PhillipsEgan2009.pdf

Perceptual representation of visible surfaces

Thu, 29 Mar 2007 11:44:43 -0400

Phillips, F, Todd, JS, Koenderink, JJ & Kappers, AML (2003). Perceptual representation of visible surfaces. Perception & Psychophysics, 65(5), 747-762.

Part of my thesis work - what sorts of things are we representing when we talk about 3D shape?

PhillipsToddKoenderinkKappers2003.pdf

Science and Storyboards

Wed, 27 Sep 2006 11:04:25 -0400

I gave a talk at OSU (and St. Rose a while back) on how we can use some of the story-telling and building techniques we know from filmmaking / animation to help us design, analyze, and communicate experiments.

The gang at C/S/E/L did a podcast of it, available here -
http://csel.eng.ohio-state.edu/podcasts/flip/Story.html

I stole the title of the tail from Andrew Stanton’s CalArts student film. Oh, and I hate my whiny voice.

Effects of 3-D complexity on the perception of 2-D depictions of objects

Mon, 22 May 2006 11:54:20 -0400

Phillips, F, Thompson, CH & Voshell, MG (2004). Effects of 3-D complexity on the perception of 2-D depictions of objects. Perception, 33, 21–33.

This work was so much fun. Pictures, resolution, noisy objects, photos of Koenderink - this thing had it all!

Here’s the PDF - PhillipsEtAl2004.pdf

Here are the posters from ARVO ’00 - PhillipsThompson2000.pdf
and VSS ’01 - PhillipsVoshell2001.pdf

Perception and Action at a Distance

Tue, 2 May 2006 15:04:51 -0400

Phillips, F., Gaudino, B. M., Prue, B., & Voshell, M.G. (2006). Perception and Action at a Distance[Abstract]. To Appear Journal of Vision, http://journalofvision.org/.

Teleoperation of robots and autonomous vehicles introduces an interesting series of questions with respect to perception and action at a distance. While the pragmatics of this problem has been considered in the human factors domain, there is little consideration of an overall theory of perception and action at a distance in the perceptual domain. Our work attempts to erect a scaffolding for the development of such a theory. Classically, studies of perception and action take place in the 1st-person, i.e., those where the embodiment of the perceiver and actor are the same entity. Our work considers the 2nd- and 3rd-person perspectives (e.g., watching a machine carrying out our action and watching from the machine carrying out the action). The framework is complicated by the fact that 2nd- and 3rd-person embodiments may have different action capabilities than the 1st-person, and 3rd-person embodiments may have additional sensor mechanisms able to provide information not available in the usual 1st-person sense. Our overall strategy consists of 2nd- and 3rd-person replication of classic 1st-person perception-action paradigms and investigation the resulting shifts (or lack thereof) in performance. Obviously some types of performance will have little or no difference when differently-embodied while others should experience significant modification. From these results, we can model and predict expected performance in alternative perception-action embodiments. Here, we present initial results from an affordance-based experiment modeled on Warren & Wang (1987) as well as navigation experiments after Foo et al. (2005), along with their relevant implications for our proposed theoretical framework.

HJDPart2.zip

After we presented this, we sort of had a ‘crisis’ over the use of “1st/2nd/3rd person.”

We’ve since made some constructive changes to the framework / structure that look sort of like this:

This will be better spelled out in the Gaudino Prue thesis that I’ll post on the thesis page soon.

The perception of surface orientation from multiple sources of optical information

Mon, 20 Feb 2006 10:23:11 -0500

Norman, JF, Todd, JT & Phillips, F (1995). The perception of surface orientation from
multiple sources of optical information. Perception & Psychophysics, 57(5), 629–636.

If I recall correctly, this paper grew out of one of those reviews that said “Well, sure, you did stereo, but what about motion, texture, blah blah blah.”

So, Farley whipped up the factorial-experiment-from-hell. Shading, Highlights, Texture, Stereo, Motion. At one point during the process of running the 10.8 billion trials I think I contemplated eating glass.

Feel our pain here.

Information concentration along the boundary contours of naturally shaped solid objects

Mon, 20 Feb 2006 10:12:30 -0500

Norman, JF, Phillips, F & Ross, HE (2001). Information concentration along the boundary contours of naturally shaped solid objects. Perception, 30, 1285=1294.

Certainly among my favorite papers. Farley used shadows from actual sweet potatoes (Ipomoea batatas) for stimuli and had folks mark regions of convexity and concavity. We looked at the characteristics of the shape in the regions that people were likely to mark.

We have another shadow paper in the works. I need to get off my butt and finish the analysis.

Grab the PDF here.

Surface Range and Attitude Probing in Stereoscopically Presented Dynamic Scenes

Fri, 10 Feb 2006 12:56:01 -0500

Koenderink, JJ, Kappers, AML, Todd, JT, Norman, JF & Phillips, F (1996). Surface range and attitude probing in stereoscopically presented dynamic scenes. Journal of Experimental Psychology: Human Perception and Performance, 22(4), 869-878.

This is among my early collaborations with Koenderink. The origins of my understanding of shape reconstruction, mental representation, stereopsis, & no doubt a host of other things.

We did some of this work at Ohio State, I seem to remember Jan’s backpack said “Flying Dutchman” on it, which I found hilarious. This was probably also the trip where he explained the Dutch pastime of fierljeppen or “dyke-jumping”.

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What can drawing tell us about our mental representation of shape?

Sun, 29 Jan 2006 14:27:46 -0500

Phillips, F., Casella, M. W., & Gaudino, B. M. (2005). What can drawing tell us about our mental representation of shape? [Abstract]. Journal of Vision, 5(8), 522a, http://journalofvision.org/5/8/522/, doi:10.1167/5.8.522.

When we draw or sketch a three-dimensional object, what aspects of its geometric structure do we usually choose to depict and how are these depictions executed? More importantly, what can these renderings tell us about our mental representation of these shapes? Art instruction literature and practice is replete with techniques for depicting objects. Not surprisingly, in such a large variety of sources there is a large amount of contradictory advice. Despite this, it is obvious that even the simplest and most naïve drawing can convey information about shape. Willats et al. have investigated a wide variety of spatially representational drawing techniques and have developed a broad taxonomy based around them. We are interested in furthering our understanding of the mental representation of objects via direct comparison of drawing production with the depicted objects. We performed a series of experiments designed to correlate the markings made when depicting an object with the object's underlying differential structure. In one scenario, subjects were shown two-dimensional renderings of random, smooth, three-dimensional objects from a dynamically changing view point. As there was no fixed viewpoint the subject couldn't depict the object by simply replicating image information. (Many classical drawing techniques suggest this sort of 'drawing from the image'.) The resulting drawings are, therefore, likely to be based on a three-dimensional mental representation derived during the viewing period. In other conditions, subjects were shown static boundary contours, static shaded images, dynamic images with subject-controlled viewpoint, and physically realized three-dimensional models. Each of these conditions provides a different variety and quantity of image information to the illustrator. Results from each are compared to contrast the information derived and depicted directly from the optical image with the information available in some higher-level representation.

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http://www.journalofvision.com/5/8/522/

Combinational Imaging: MRI & EEG

Fri, 27 Jan 2006 10:41:47 -0500

Torello, MW, Phillips, T, Hunter, WW & Csuri, CA (1987). Combinational imaging: Magnetic Resonance Imaging and EEG displayed simultaneously. Journal of Clinical Neurophysiology, 4(3), 274-257.

I think this is my second ever publication. (The first was also with Torello, also on the same stuff.) It was based on work Mike and I did back in 1985-1986 at the Computer Graphics Research Group at OSU. Csuri ran CGRG and Hunter ran the MRI facility. MRI was a brand-spanking-new imaging technology back then, I started working at CGRG in 1984 and got in on this project, where I met Mike Torello who has remained a good friend to this day (and my inspiration for returning to academia actually). At the time we started the project the scanner technology hadn’t been FDA approved for humans yet. “Sure, I’ll hop in there.” Ahh youth.

Mike was interested in temporal-lobe morphology in schizophrenics, so we would take ‘normal’ baseline folks and schizophrenic folks, have them perform basic tasks monitored via EEG. While removing the EEG cap a small Vitamin-E capsule was glued to the scalp at each electrode location. When we put them in the MRI scanner, the oil in the capsule would light up like a light bulb in the resulting images. Then, when we did the 3D reconstruction of the brain, we could calculate a ‘cap’ to superimpose at the skull-level that reflected the electrical activity. We had animations of various viewpoints and temporal changes in the EEG.

Later, while at Pixar, I developed a volumetric method to do the same thing that had better calculations of the activity, based on physiological models. We never published that, Mike left OSU and, via Sleep Research, ended up as a happily tenured full professor at Capital University.

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