Gaze Media Player

The component I´ve been working on is now capable of the basics. Great feeling just looking a song titles and then skipping through the playlist by gaze =) There is room for improvements, would be nice have a component like a slider where one could go to a specific part of the song. (don´t know how many times I´ve been playing guitar to a song while learning it and going back and forth between mouse and guitar. Let´s see what a weekend could do =)

Screenshot of the music player component, layout not finalized.. Updated version has a song progression bar and volume controls.

The play-button houses another ellipse shaped menu with the regular controls for (next, previous, play, stop)

RApid GAze-Based Interaction Techniques (RAGABITS)

Stephen Vickers at the Computer Human Interaction Research Group at the De Montfort University, Uk have developed interaction techniques that allows gaze based control of several popular online virtual worlds such as World of Warcraft or Second Life. This research will be presented at ETRA 2008, US under the title RAGABITS (RApid GAze-Based Interaction Techniques) and is espcially intented for users with severe motor impairments.

Selection method seems stable. None of the usual jitter can be seen. Nice!



Quote from http://www.ioct.dmu.ac.uk/projects/eyegaze.html

"Online virtual worlds and games (MMORPG's) have much to offer users with severe motor disabilities. It gives this user group the opportunity as entirely able-bodied to others in the virtual world. if they so wish. The extent to which a user has to reveal their disability becomes a privacy issue. Many of the avatars in Second Life appear as stylized versions of the users that control them and that stylization is the choice of the user. This choice is equally appropriate for disabled users. While the appearance of the user's avatar may not reveal the disability of the person that controls it, the behavior and speed or interaction in the world may do.

Many users with severe motor impairments may not be able to operate a keyboard or hand mouse and may also struggle with speech and head movement. Eye gaze is one method of interaction that has been used successfully in enabling access to desktop environments. However, simply emulating a mouse using eye gaze is not sufficient for interaction in online virtual worlds and the users privacy can be exposed unless efficient gaze-based interaction techniques, appropriate to activities in on-line worlds and games can be provided.

This genre of gaming (MMORPG's) is constantly evolving and regardless of the aim of the game they all involve common tasks such as, avatar creation, social interaction (chatting, IM), interaction with in world objects (pick up, open, shoot etc), navigating and walking around the environment. Our research involves analyzing these common tasks so that suitable gaze based interaction techniques to support them can be used in place of a mouse and keyboard. These will have different performance/effort trade-offs, and will include extended mouse/joystick emulation, gaze gestures, toolglasses and gaze-aware in-world objects. These techniques need to be integrated into a coherent and efficient user interface suited to the needs of an individual user with a particular disability. The research aims to model tasks inherent in using these worlds so that predictions can be made about the most appropriate gaze based interaction techniques to use. When these have been identified, they can be assembled into a front end or user interface. One possible outcome could be a software device for automatic configuration of a gaze-control interface for new games, which could use knowledge of a specific user's disability and the eye tracking equipment that they have."

Last week of prototyping

Being back from a short easter holiday the final week of developing the prototype is here. The functionality of the interface is OK but there is major tweaking and bug testing to be performed. The deadline for any form of new features is Monday 31st of March. I intend to use all of April for setting up the evaluation experiments and procedures. As always there is so much more that I would like to incorporate, every day brings new ideas.

The final version will include:

• A configurable dwell button component. This enables drag and drop dwell buttons into Windows projects with individual configuration on dwell-time and icons etc.
  
  
• A novel gaze based menu system that utilized saccade selection (two step dwell) This highly configurable interface component displays itself when activated. It aims at solving the midas touch problem while utilizing the screen real estate in a better way. The two steps in the activation process can be set to specific activation-speeds (dwells) More on this later..
  
  
• A gaze-based memory game using a 36 card layout. By perfoming a dwell the cards "turn" over and shows its symbol (flag). The user the selects another card. If matching then remove them. If different, turn them back over. Got some nice graphical effects.
  
  
• A gaze based picture viewer that zooms into the photos in gaze of the user. More on this later.
  
  
• A gaze based media/music player. This component will scan the computer for artists, albums and songs. These items are then accessible by a gaze driven interface where the user can create play-lists and perform the usual functions (volume+-, pause, stop, next, previous etc.)
  
  
• Perhaps just one little surprise more..
  

Eight weeks so far. Curiosity, dedication and plain ol´ hard work, nothing else to it.

Inspiration: Real-Time Facial and Eye Gaze Tracking System (Park&Kim, 2005)

While my main concern is gaze interaction it´s important to understand the underlying technology which makes it all possible (and the limitation it poses) Much work has gone into solving issues surrounding image processing that makes the "new" remote eye tracking systems we see today possible. One solution to battle the low resolution of cameras is presented in the paper below (using dual cameras) Additionally, the issues of reflections from glasses solved using dual IR-leds. Interesting paper, technical information on Kahlman algorithms etc. used to achieve a 15 frames / second eye tracker on an old Pentium IV 2.0GHz.

Abstract
The goal of gaze detection is to locate the position (on a monitor) where a user is looking. Previous researches use one wide view camera, which can capture the user's entire face. However, the image resolution is too low with such a camera and the fine movements of user's eye cannot be exactly detected. So, we propose the new gaze detection system with dual cameras (a wide and a narrow view camera). In order to locate the user's eye position accurately, the narrow-view camera has the functionalities of auto focusing/panning/tilting based on the detected 3D eye positions from the wide view camera. In addition, we use the IR-LED illuminators for wide and narrow view camera, which can ease the detecting of facial features, pupil and iris position. To overcome the problem of specular reflection on glasses by illuminator, we use dual IR-LED illuminators for wide and narrow view camera and detect the accurate eye position, which is not hidden by the specular reflection. Experimental results show that the gaze detection error between the computed positions and the real ones is about 2.89 cm of RMS error.


The paper is written by prof. Kang Ryoung Park who is heading the Computer Graphics & Vision department at the Sangmyung University, Korea (publications)

Co-author prof. Jaihie Kim is the head of the Computer Vision lab at the Yonsei University, Korea (publications)

Inspiration: Takehiko Ohno

Working out of NTT Cyber Solutions Laboratories in Japan Takehiko interests lies mainly in eye tracking technology and human computer interaction. He has published several papers on eye tracking technology and interaction methods. The QuickGlance selection method aims to solve the well known Midas-touch problem. The interface contains a specific selection area next to each choice/item which must be fixated to activate the function. There are two major advantages with this. First, the user can look around at the menu items without worrying about accidentally activating something. Second, advanced users can go for the activation area directly without even reading the menu text. Just like most people know the order/location of items on the Windows Start-menu. On the downside this means that all options are displayed on the screen all the time.

Takehiko additionally have published several articles on FreeGaze, a remote based system which allows the user to move around his head freely. The FreeGaze eye tracker at NTT has a 0.28 degree of accuracy and is based on a rather wide stereoscopic corneal reflection method using serveral image processing algorithms described in the papers, which are well written and worth reading.

His research highlights the importance of providing feedback to the user as the major method of reducing error rates. Something that I've taken to heart.

• Publications
  
  
• Website

COGAIN 2008: Communication, Environment and Mobility Control by Gaze

This years COGAIN conference will be held in Prague, 2-3 September. Detailed information on paper submission, program, dates, venues etc can be found at http://www.cogain.org/cogain2008

Themes this year are

• Text entry by means of gaze
• Gaze and environmental control
• Gaze and personal mobility control
• Direct interaction with gaze aware real world objects
• User experience studies
• Innovations in eyetracking systems
• Low cost gaze tracking systems
• Attentive interfaces and inferring user intent from gaze
• Gaze-based interaction with virtual worlds
• Gaze and creativity
• Gaming using gaze as an input modality
• Using gaze with other modalities including BCI

Eye Gaze Interaction with Expanding Targets (Minotas, Spakov, MacKenzie, 2004)

Continuing on the topic of expanding areas this paper presents an approach where the expansion of the target area is invisible.The authors introduce their algorithm called "Grab-and-hold" which aims at stablizing the gaze data and performs a two part experiment to evaluate it.

Abstract
"Recent evidence on the performance benefits of expanding targets during manual pointing raises a provocative question: Can a similar effect be expected for eye gaze interaction? We present two experiments to examine the benefits of target expansion during an eye-controlled selection task. The second experiment also tested the efficiency of a “grab-and-hold algorithm” to counteract inherent eye jitter. Results confirm the benefits of target expansion both in pointing speed and accuracy. Additionally, the grab-and-hold algorithm affords a dramatic 57% reduction in error rates overall. The reduction is as much as 68% for targets subtending 0.35 degrees of visual angle. However, there is a cost which surfaces as a slight increase in movement time (10%). These findings indicate that target expansion coupled with additional measures to accommodate eye jitter has the potential to make eye gaze a more suitable input modality." (Paper available here)

Their "Grab-and-hold" algorithm that puts some more intelligent processing of the gaze data. "Upon appearance of the target, there is a settle-down period of 200 ms during which the gaze is expected to land in the target area and stay there. Then, the algorithm filters the gaze points until the first sample inside the expanded target area is logged. When this occurs, the target is highlighted and the selection timer triggered. The selection timer counts down a specified dwell time (DT) interval. "

While reading this paper I came to think about an important question concerning filtering of gaze data. The delay that comes from collecting the samples used for the algorithm processing causes a delay in the interaction. For example, if I were to sample 50 gaze positions and then average these to reduce the jitter it would result in a one second delay on a system that captures 50 images per second (50Hz) As seen in other papers as well there is a speed-accuracy trade off to make. What is more important, a lower error rate or a more responsive system?

Application of Fitts Law to Eye Gaze Interaction Interfaces (Miniotas, 2000)

Fitts's law (often cited as Fitts' law) is a model of human movement which predicts the time required to rapidly move to a target area, as a function of the distance to the target and the size of the target. Paul M. Fitts (1912 – 1965) was a psychologist at Ohio State University (later at the University of Michigan). He developed a model of human movement, Fitts's law, based on rapid, aimed movement, which went on to become one of the most highly successful and well studied mathematical models of human motion. Fitts's law is used to model the act of pointing, both in the real world (e.g., with a hand or finger) and on computers (e.g., with a mouse) (Source: Wikipedia, 2008-03-11)

I became interested when I found the paper "Application of Fitts Law to Eye Gaze Interaction Interfaces" by Darius Miniotas (2000) at the Siauliai University, Lithuania. The study does only contain six participants. The task consists of keeping a fixation within 26mm x 26mm box continuously for 250ms. Knowing the noise and jitter in all eye trackers (the one I'm using is state-of-the-art 2008) the task might not be the best one for illustrating Fitts law while using eye trackers. Additionally, presenting a visual indicator of gaze position may appear as distracting due to often present offsets in eye tracking algorithms (somewhat off and moving around).

Abstract

An experiment is described comparing the performance of an eye tracker and a mouse in a simple pointing task. Subjects had to make rapid and accurate horizontal movements to targets that were vertical ribbons located at various distances from the cursor's starting position. The dwell-time protocol was used for the eye tracker to make selections. Movement times were shorter for the mouse than for the eye tracker. Fitts' Law model was shown to predict movement times using both interaction techniques equally well. The model is thus seen to be a potential contributor to design of modern multimodal human computer interfaces. (ACM Paper)

Inspiration: Professor Andrew Duchowksi

Andrew Duchowski is one on the leading authorities on eye tracking and gaze interaction working out of the College of Engineering and Science at Clemson University (South Carolina, U.S.) Andrew is involved in organizing the annual Eye Tracking Research and Applications Symposium (ETRA) conference.

Research interests

• Visual perception and human-computer interaction.
• Computer graphics, eye tracking, virtual environments.
• Computer vision and digital imaging.
• Wavelet and multi-resolution analysis.

Andrew has published the book Eye Tracking Methodology: Theory and Practice which is one of the very few titles within the field which is especially oriented towards practical research and technical development. Well worth reading if your aiming at developing gaze driven applications (deals with algorithms, experimental setup etc)

Eye Tracking Methodology: Theory and Practice, 2nd ed.
Duchowski, A. T. (2007), Springer-Verlag, London, UK.
ISBN: 978-1-84628-808-7


Resume, talks and publications

Inspiration: Professor Rob Jacobs (Mr Midas Touch)

Rob Jacobs, currenly at Tufts University, was early on interested in gaze based interaction. Jacobs have a long list of both honors, publications and presentations in the HCI field. Being the founder of the "Midas Touch" analogy and many other fundamental aspects of gaze interaction the guy clearly deserves an introduction.


From his homepage

"Robert Jacob is a Professor of Computer Science at Tufts University, where his research interests are new interaction media and techniques and user interface software. He is currently also a visiting professor at the Universite Paris-Sud, and he was a visiting professor at the MIT Media Laboratory, in the Tangible Media Group, and continues collaboration with that group. Before coming to Tufts, he was in the Human-Computer Interaction Lab at the Naval Research Laboratory. He received his Ph.D. from Johns Hopkins University, and he is a member of the editorial board of Human-Computer Interaction and the ACM Transactions on Computer-Human Interaction. He was Papers Co-Chair of the CHI 2001 conference, Co-Chair of UIST 2007, and Vice-President of ACM SIGCHI. He was elected to the ACM CHI Academy in 2007, an honorary group of people who have made extensive contributions to the study of HCI and have led the shaping of the field."

Research topics:
Human-Computer Interaction
New Interaction Techniques and Media
Tangible User Interfaces
Virtual Environments
User Interface Software
Information Visualization

Must-read:

R.J.K. Jacob, “The Use of Eye Movements in Human-Computer Interaction Techniques: What You Look At is What You Get,” ACM Transactions on Information Systems, vol. 9, no. 3, pp. 152-169 (April 1991) [link]

L.E. Sibert and R.J.K. Jacob, “Evaluation of Eye Gaze Interaction,” Proc. ACM CHI 2000 Human Factors in Computing Systems Conference, pp. 281-288, Addison-Wesley/ACM Press (2000). [link]

Inspiration: Dwell-Based Pointing in Applications (Muller-Tomfelde, 2007)

While researching the optimal default value for dwell time execution I stumbled upon this paper by Christian Muller-Tomfelde at the CSIRO ICT Centre, Australia. It does not concern dwell time in the aspect of gaze based interaction but instead focuses on how we handle dwell times while pointing towards objects and conveying this reference to a communication partner. How long can this information be withheld before the interaction becomes unnatural?

Abstract
"This paper describes exploratory studies and a formal experiment that investigate a particular temporal aspect of human pointing actions. Humans can express their intentions and refer to an external entity by pointing at distant objects with their fingers or a tool. The focus of this research is on the dwell time, the time span that people remain nearly motionless during pointing at objects. We address two questions: Is there a common or natural dwell time in human pointing actions? What implications does this have for Human Computer Interaction? Especially in virtual environments, feedback about the referred object is usually provided to the user to confirm actions such as object selection. A literature review and two studies led to a formal experiment in a hand-immersive virtual environment in search for an appropriate feedback delay time for dwell-based pointing actions. The results and implications for applications for Human Computer Interaction are discussed. "

I find the part about the visual feedback experiment interesting.

"We want to test whether a variation of the delay of an explicit visual feedback for a pointing action has an effect of the perception of the interaction process. First, feedback delay time above approximately 430 ms is experienced by users to happen late. Second, for a feedback delay time above approximately 430 ms users experience waiting for feedback to happen and third, feedback delay below 430 ms is considered by users to be natural as in real life conversations. "

Questions asked:

• 1: Do you have the impression that the system feedback happened in a reasonable time according to your action? Answer: confirmation occurred too fast (1), too late (7).

• 2: Did you have the feeling to wait for the feedback to happen? Answer: no I didn’t have to wait (1), yes, I waited (7).
  
  
• 3: Did you have the impression that the time delay for the feedback was natural? (i.e., as in a real life communication situation) Answer: time delay is not natural (1), quite natural (7).
  

"This allows us to recommend a feedback delay time for manual pointing actions of approximately 350 to 600 ms as a starting point for the development of interactive applications. We have shown that this feedback delay is experienced by users as natural and convenient and that the majority of observers of pointing actions gave feedback within a similar time span."

Technology: Consumer-grade EEG devices

Not exactly eye tracking but interesting as a combined modality are the upcoming consumer grade Electroencephalography (EEG) devices sometimes referred to as "brain-mouse". The devices are capable of detecting brain activity by electrodes placed on the scalp.

The company OCZ Technology, mainly known for it's computer components such a memory and power supplies, have announced the "Neural Impulse Actuator (NIA)". While this technology itself is nothing new the novelty lies in the accessibility of the device, priced somewhere around $200-250 when introduced next week.

Check out the quick mini-demo by the guys at Anandtech from the Cebit exhibition in Hannover, 2008
This technical presentation (in German) goes into a bit more detail.


From the press release:
"Recently entering mass production, the final edition of the Neural Impulse Actuator (NIA) will be on display for users to try out the new and electrifying way of playing PC games. The final version of the NIA uses a sleek, metal housing, a USB 2.0 interface, a streamlined headband with carbon interface sensors, and user-friendly software. The NIA is the first commercially available product of its kind, and gamers around the world now have access to this forward-thinking technology that’s had the industry buzzing since its inception."

These devices do have the potential for taking the whole hands-free computing to the next level. They could be a feasible candidate for solving the midas touch problem by proving a device that enables the user to perform activations by subtle facial gestures etc. I have yet to discover how sensitive this device is and what the latency is. Additionally, does it come with an API?

I've tried research grade EEG devices as means for interaction while at the University of California, San Diego and pure thoughts of actions are hard to detect in a stable manner. It is well known in the neuroscience community that thought of actions activates the same regions in the brain as would be activated by actually performing them. We even have mirror neurons that are activated by observing other people performing goal-directed actions (picking up that banana) The neural activation of pure thought alone is subtle and hard to detect compared to performing actual movements, such as lifting ones arm. So, I do not expect it to be an actual Brain Computer Interface (BCI) capable of detecting thoughts (ie. thinking of kicking etc.) but more a detector of subtle motions in my forehead muscles (eye and eye brown movements, facial expressions etc.)

The firm Emotive has their own version of a consumer grade EEG which is named Epoc NeuroHeadset, it has been around for a little longer and seem to have a more developed software, but still mainly demonstration applications.

The Emotive NeuroHeadset

Inspiration: All Eyes on the Monitor (Mollenbach et al, 2008)

Going further with the Zooming User Interface (ZUI) is the prototype descibed in the "All Eyes on the Monitor: Gaze Based Interaction in Zoomable, Multi-Scaled Information-Space" (E. Mollenbach, T. Stefansson, J-P Hansen) developed at the Loughborough University in the U.K and the ITU INC, Denmark. It employes the gaze based pan/zoom interaction style which is suitable for gaze interaction to resolve the inaccuracy (target sizes increase when zooming in to them) Additionally, the results indicate that for certain tasks gaze based interaction is faster than traditional mouse operation.

ABSTRACT

The experiment described in this paper, shows a test environment constructed with two information spaces; one large with 2000 nodes ordered in semi-structured groups in which participants performed search and browse tasks; the other was smaller and designed for precision zooming, where subjects performed target selection simulation tasks. For both tasks, modes of gaze- and mouse-controlled navigation were compared. The results of the browse and search tasks showed that the performances of the most efficient mouse and gaze implementations were indistinguishable. However, in the target selection simulation tasks the most efficient gaze control proved to be about 16% faster than the most efficient mouse-control. The results indicate that gaze-controlled pan/zoom navigation is a viable alternative to mouse control in inspection and target exploration of large, multi-scale environments. However, supplementing mouse control with gaze navigation also holds interesting potential for interface and interaction design. Download paper (pdf)

The paper was presented at the annual International Conference for Intelligent Interfaces (IUI) that was held in Maspalomas, Gran Canaria between 13-16th January 2008.

Zooming and Expanding Interfaces / Custom componenets

The inspiration I got from the reviewed papers on using a zooming interaction style to developing a set of zoom based interface components. The interaction style is suitable for gaze to overcome the inaccuracy and jitter of eye movements. My intention is that the interface components should be completely standalone, customizable and straightforward to use. Ideally included in new projects by importing one file and writing one line of code.

The first component is a dwell-based menu button that on fixation will a) provide a dwelltime indicator by animating a small glow effect surrounding the button image and b) after 200ms expand an ellipse that houses the menu options. This produces a two step dwell activation while making use of the display area in a much more dynamic way. The animation is put in place to keep the users fixation remained at the button for the duration of the dwell time. The items in the menu are displayed when the ellipse has reached its full size.

This gives the user a feedback in his parafoveal region and at the same time the glow of the button icon has stopped indicating a full dwelltime execution. (bit hard to describe in words, perhaps easier to understand from the images below) The parafoveal region of our visual field is located just outside the foveal region (where the full resolution vision takes place). The foveal area is about the size of a thumbnail on an armslengths distance, items in the parafoveal region still can be seen but the resolution/sharpness is reduced. We do see them but have to make a short saccade for them to be in full resolution. In other words the menu items pop out at a distance that attracts a short saccade which is easily discriminated by the eye tracker. (Just4fun test your visual field)

Before the button has received focus

Upon fixation the button image displays an animated glow effect indicating the dwell process. The image above illustrates how the menu items pops out on the ellipse surface at the end of the dwell. Note that the ellipse grows in size during a 300ms period, exact timing is configurable by passing a parameter in the XAML design page.

The second prototype I have been working on is also inspired by the usage of expanding surfaces. The purpose is a gaze driven photo gallery where thumbnail sized image previews becomes enlarged upon glancing at them. The enlarged view displays an icon which can be fixated to make the photo appear in full size.

Displaying all the images in the users "My pictures" folder.

Second step, glancing at the photos. Dynamically resized. Optionally further enlarged.

Upon glancing at the thumbnails they become enlarged which activates the icon at the bottom of each photo. This enables the user to make a second fixation on it to bring the photo into a large view. This view has to two icons to navigate back and forth (next photo). By fixating outside the photo the view goes back to the overview.

Read more >> Options >>

Talk: Sensing user attention (R. Vertegaal)

Stumbled upon a talk by Roel Vertegaal at Google Techtalk describing various projects at the Queens University Human Media Lab, many of which are using eye tracking technology. In general, applies knowledge from cognitive science on attention and communication onto practical Human-Computer Interaction interfaces applications. Overall nice 40 minute talk. Enjoy.

Abstract
Over the past few years, our work has centered around the development of computing technologies that are sensitive to what is perhaps the most important contextual cue for interacting with humans that exists: the fabric of their attention. Our research group has studied how humans communicate attention to navigate complex scenarios, such as group decision making. In the process, we developed many different prototypes of user interfaces that sense the users' attention, so as to be respectful players that share this most important resource with others. One of the most immediate methods for sensing human attention is to detect what object the eyes look at. The eye contact sensors our company has developed for this purpose work at long range, with great head movement tolerance, and many eyes. They do not require any personal calibration or coordinate system to function. Today I will announce Xuuk's first product, EyeBox2, a viewing statistics sensor that works at up to 10 meters. EyeBox2 allows the deployment of algorithms similar to Google's PageRank in the real world, where anything can now be ranked according to the attention it receives. This allows us, for example, to track mass consumer interest in products or ambient product advertisements. I will also illustrate how EyeBox2 ties into our laboratory's research on interactive technologies, showing prototypes of attention sensitive telephones, attentive video blogging glasses, speech recognition appliances as well as the world's first attentive hearing aid.


Roel Vertegaal is the director of the Human Media Lab at the Queen's University in Kingston, Canada. Roel is the founder of Xuuk which offers the EyeBox2, a remote eye tracker that works on up to 10 meters distance (currently $1500) and associated analysis software.

Inspiration: EyeWindows (Fono et al, 2005)

Continuing on the zooming style of interaction that has become common within the field of gaze interaction is the "EyeWindows: Evalutaion of Eye-Controlled Zooming Windows for Focus Selection" (Fono&Vertegaal, 2005) Their paper describes two prototypes, one media browser with dynamic (elastic) allocation of screen real estate. The second prototype is used to dynamically size desktop windows upon gaze fixation. Overall, great examples presented in a clear, well structured paper. Interesting evaluation of selection techniques.



Abstract
In this paper, we present an attentive windowing technique that uses eye tracking, rather than manual pointing, for focus window selection. We evaluated the performance of 4 focus selection techniques: eye tracking with key activation, eye tracking with automatic activation, mouse and hotkeys in a typing task with many open windows. We also evaluated a zooming windowing technique designed specifically for eye-based control, comparing its performance to that of a standard tiled windowing environment. Results indicated that eye tracking with automatic activation was, on average, about twice as fast as mouse and hotkeys. Eye tracking with key activation was about 72% faster than manual conditions, and preferred by most participants. We believe eye input performed well because it allows manual input to be provided in parallel to focus selection tasks. Results also suggested that zooming windows outperform static tiled windows by about 30%. Furthermore, this performance gain scaled with the number of windows used. We conclude that eye-controlled zooming windows with key activation provides an efficient and effective alternative to current focus window selection techniques. Download paper (pdf).

David Fono, Roel Vertegaal and Conner Dickie are researchers at the Human Media Lab at the Queen's University in Kingston, Canada.

Inspiration: Fisheye Lens (Ashmore et al. 2005)

In the paper "Efficient Eye Pointing with a Fisheye Lens" (Ashmore et al., 2005) the usage of a fish eye magnification lens is slaved to the foveal region of the users gaze. This is another usage of the zooming style of interaction but compared to the ZoomNavigator (Skovsgaard, 2008) and the EyePointer (Kumar&Winograd, 2007) this is a continuous effect that will magnify what ever the users gaze lands upon. In other words, it is not meant to be a solution for dealing with the low accuracy of eye trackers in typical desktop (windows) interaction. Which makes is suitable for tasks of visual inspection for quality control, medical x-ray examination, satellite images etc. On the downside the nature of the lens distorts the image which breaks the original spatial relationship between items on the display (as demonstrated by the images below)

Abstract
"This paper evaluates refinements to existing eye pointing techniques involving a fisheye lens. We use a fisheye lens and a video-based eye tracker to locally magnify the display at the point of the user’s gaze. Our gaze-contingent fisheye facilitates eye pointing and selection of magnified (expanded) targets. Two novel interaction techniques are evaluated for managing the fisheye, both dependent on real-time analysis of the user’s eye movements. Unlike previous attempts at gaze-contingent fisheye control, our key innovation is to hide the fisheye during visual search, and morph the fisheye into view as soon as the user completes a saccadic eye movement and has begun fixating a target. This style of interaction allows the user to maintain an overview of the desktop during search while selectively zooming in on the foveal region of interest during selection. Comparison of these interaction styles with ones where the fisheye is continuously slaved to the user’s gaze (omnipresent) or is not used to affect target expansion (nonexistent) shows performance benefits in terms of speed and accuracy" Download paper (pdf)

The fish eye lens has been implemented commercially into the products of Idelix Software Inc. which has a set of demonstration available.

Inspiration: GUIDe Project (Kumar&Winograd, 2007)

In the previous post I introduced the ZoomNavigator (Skovsgaard, 2008) which is similar to the EyePointer system (Kumar&Winograd, 2007) developed within the GUIDe project (Gaze-Enhaced User Interface Design) an initiative by the department for Human Computer Interaction at Stanford University. This system relies on both an eye tracker and a keyboard which excludes users with disabilities (see video below). The aim of the GUIDe is to make the whole human-computer interaction "smarter" (as in intuitive, faster & less cumbersome) This differs from the COGAIN initiative which mainly aims at giving people with disabilities a higher quality of life.

Abstract
"The GUIDe (Gaze-enhanced User Interface Design) project in the HCI Group at Stanford University explores how gaze information can be effectively used as an augmented input in addition to keyboard and mouse. We present three practical applications of gaze as an augmented input for pointing and selection, application switching, and scrolling. Our gaze-based interaction techniques do not overload the visual channel and present a natural, universally-accessible and general purpose use of gaze information to facilitate interaction with everyday computing devices." Download paper (pdf)

Demonstration video
"The following video shows a quick 5 minute overview of our work on a practical solution for pointing and selection using gaze and keyboard. Please note, our objective is not to replace the mouse as you may have seen in several articles on the Web. Our objective is to provide an effective interaction technique that makes it possible for eye-gaze to be used as a viable alternative (like the trackpad, trackball, trackpoint or other pointing techniques) for everyday pointing and selection tasks, such as surfing the web, depending on the users' abilities, tasks and preferences."

The use of "focus points" is good design decisions as it provides the users with a fixation point which is much smaller than the actual target. This provides a clear and steady fixation which is easily discriminated by the eye tracker. The idea of displaying something that will "lure" the users fixation to remain still is something I intend to explore in my own project.

As mentioned the GUIDe project has developed several applications besides the EyePoint, such as the EyeExpose (application switching), gaze-based password entry, automatic text scrolling.
More information can be found in the GUIDe Publications

Make sure to get a copy of Manu Kumars Ph.D thesis "Gaze-enhanced User Interface Design" which is pleasure to read. Additionally, Manu have founded GazeWorks a company which aims at making the technology accessible for the general public at a lower cost.

Inspiration: ZoomNavigator (Skovsgaard, 2008)

Following up on the StartGazer text entry interface presented in my previous post, another approach to using zooming interfaces is employed in the ZoomNavigator (Skovsgaard, 2008) It addresses the well known issue of using gaze as input on traditional desktop systems, namely inaccuracy and jitter. Interesting solution which relies on dwell-time execution compared to the EyePoint system (Kumar&Winograd, 2007) which is described in the next post.

Abstract
The goal of this research is to estimate the maximum amount of noise of a pointing device that still makes interaction with a Windows interface possible. This work proposes zoom as an alternative activation method to the more well-known interaction methods (dwell and two-step-dwell activation). We present a magnifier called ZoomNavigator that uses the zoom principle to interact with an interface. Selection by zooming was tested with white noise in a range of 0 to 160 pixels in radius on an eye tracker and a standard mouse. The mouse was found to be more accurate than the eye tracker. The zoom principle applied allowed successful interaction with the smallest targets found in the Windows environment even with noise up to about 80 pixels in radius. The work suggests that the zoom interaction gives the user a possibility to make corrective movement during activation time eliminating the waiting time found in all types of dwell activations. Furthermore zooming can be a promising way to compensate for inaccuracies on low-resolution eye trackers or for instance if people have problems controlling the mouse due to hand tremors.

The sequence of images are screenshots from ZoomNavigator showing
a zoom towards a Windows file called ZoomNavigator.exe.

The principles of ZoomNavigator are shown in the figure above. Zooming is used to focus on the attended object and eventually make a selection (unambiguous action). ZoomNavigator allows actions similar to those found in a conventional mouse. (Skovsgaard, 2008) The system is described in a conference paper titled "Estimating acceptable noise-levels on gaze and mouse selection by zooming" Download paper (pdf)

Two-step zoom
The two-step zoom activation is demonstrated in the video below by IT University of Copenhagen (ITU) research director prof. John Paulin Hansen. Notice how the error rate is reduced by the zooming style of interaction, making it suitable for applications with need for detailed discrimination. It might be slower but error rates drops significantly.

"Dwell is the traditional way of making selections by gaze. In the video we compare dwell to magnification and zoom. While the hit-rate is 10 % with dwell on a 12 x 12 pixels target, it is 100 % for both magnification and zoom. Magnification is a two-step process though, while zoom only takes on selection. In the experiment, the initiation of a selection is done by pressing the spacebar. Normally, the gaze tracking system will do this automatically when the gaze remains within a limited area for more than approx. 100 ms"

For more information see the publications of the ITU.

Inspiration: StarGazer (Skovsgaard et al, 2008)

A major area of research for the COGAIN network is to enable communication for the disabled. The Innovative Communications group at IT University of Copenhagen continuously work on making gaze-based interaction technology more accessible, especially in the field of assistive technology.

The ability to enter text into the system is crucial for communication, without hands or speech this is somewhat problematic. The StartGazer software aims at solving this by introducing a novel 3D approach to text entry. In December I had the opportunity to visit ITU and try the StarGazer (among other things) myself, it is astonishingly easy to use. Within just a minute I was typing with my eyes. Rather than describing what it looks like, see the video below.
The associated paper is to be presented at the ETRA08 conference in March.

Read more >> Options >>

Inspiration: COGAIN

Much of the developments seen in the field of gaze interaction stems from the assistive technology field where users whom are unable to use regular computer interfaces are provided tools to empower their everyday life in a wide range of activities such as communication, entertainment, home control etc. For example they can use the eye to type words and sentences which then are synthetically translated into spoken language by software, thus enabling communication beyond blinking. A major improvement in the quality of life.

"COGAIN (Communication by Gaze Interaction) integrates cutting-edge expertise on interface technologies for the benefit of users with disabilities. COGAIN belongs to the eInclusion strategic objective of IST. COGAIN focuses on improving the quality of life for those whose life is impaired by motor-control disorders, such as ALS or CP. COGAIN assistive technologies will empower the target group to communicate by using the capabilities they have and by offering compensation for capabilities that are deteriorating. The users will be able to use applications that help them to be in control of the environment, or achieve a completely new level of convenience and speed in gaze-based communication. Using the technology developed in the network, text can be created quickly by eye typing, and it can be rendered with the user's own voice. In addition to this, the network will provide entertainment applications for making the life of the users more enjoyable and more equal. COGAIN believes that assistive technologies serve best by providing applications that are both empowering and fun to use."

A short introduction by Dr Richard Bates, a research fellow at the School of Computing Sciences at the De Montfort University in Leicester, can be downloaded either as presentation slides or paper.

The COGAIN network is a rich source of information on gaze interaction. A set of tools developed within the network has been made publicly software available for download. Make sure to check out the video demonstations of various gaze interaction tools.

Participating organizations within the COGAIN network.

Finland

University of Tampere (UTA)
Coordinator

Denmark

IT University of Copenhagen (ITU)
Vice Coordinator

Bispebjerg Hospital (BH)
Danish Centre for Assistive Technology (DC)
Risø National Laboratory (RISOE)
Danmarks Tekniske Universitet (DTU)

Germany

Technische Universität Dresden (TU Dresden)
Universität Koblenz-Landau (UNI KO-LD)
Universität zu Lübeck (UzL)

Italy

Hewlett Packard Italiana SRL (HP)
Politecnico di Torino (POLITO)

Lithuania

Siauliu Universitetas (SU)

Sweden

Tobii Technology (Tobii)
Västra Götalands Läns Landsting (Sahlgrenska University Hospital) (DART)

United Kingdom

ACE Centre Advisory Trust Ltd (ACE)
The Chancellor, Masters and Scholars of the University of Cambridge (UCAM)
De Montfort University (DMU)
Loughborough University (LBORO)

Japan

Tokyo Institute of Technology (TIT)

Switzerland

Universität Zürich (UNIZH)

Spain

Universidad Publica de Navarra (UPNA)

Czech

Czech Technical University (CTU)

France

Metrovision (MV)

United States

LC Technologies (LC)
EyeTech Digital systems (EYETECH)

Inspiration: GazeSpace (Laqua et al. 2007)

Parallel to working on the prototypes I continuously search and review papers and thesises on gaze interaction methods / techniques, hardware and software development etc. I will post references on some of these to this blog. A great deal of research and theories on interaction / cognition lies behind the field of gaze interaction.

The paper below was presented last year on a conference held by the British Computer Society specialist group on Human Computer Interaction. Catching my attention is the focus on providing a custom content spaces (canvas), good feedback and using a dynamic dwell-time, something I intend to incorporate into my own gaze GUI components. Additionally, the idea on expanding the content canvas upon a gaze fixation is really nice and something I will attempt to do in .Net/WPF (initial work displays a set of photos that becomes enlarged upon fixation)

GazeSpace Eye Gaze Controlled Content Spaces (Laqua et al. 2007)

Abstract
In this paper, we introduce GazeSpace, a novel system utilizing eye gaze to browse content spaces. While most existing eye gaze systems are designed for medical contexts, GazeSpace is aimed at able-bodied audiences. As this target group has much higher expectations for quality of interaction and general usability, GazeSpace integrates a contextual user interface, and rich continuous feedback to the user. To cope with real-world information tasks, GazeSpace incorporates novel algorithms using a more dynamic gaze-interest threshold instead of static dwell-times. We have conducted an experiment to evaluate user satisfaction and results show that GazeSpace is easy to use and a “fun experience”. Download paper (PDF)

About the author
Sven Laqua is a PhD Student & Teaching Fellow at the Human Centred Systems Group a part of the Dept. of Computer Science at University College London. Sven has a personal homepage, university profile and a blog (rather empty at the moment)

GazeMemory v0.1a on its way

The extra time spent on developing the Custom Controls for Windows Presentation Foundation (WPF) paid off. What before that took days to develop can now be build within hours. Today I put together a gaze version of the classic game Memory which is controlled by dwell-time (prologed fixation) The "table" contains 36 cards, i.e 18 unique options. By fixating on one card a smooth animation will make the globe on the front of the card to light up and after fixating long enough (500ms) if will show the symbol (flags in first version) After selecting the fist card another is fixated and the two will be compared. If they contain the same symbols then remove them from the table. If not, turn them back over again. The interface provides several feedback mechanisms. Upon glancing the border around the buttons begins to shine, when fixating long enough the dwell time function is activated and illustrated by a white glow that smoothly fades up surrounding the globe.

The Custom Control that will be named GazeButton is to be further developed to support more features such as a configurable dwell-time, feedback such as animations, colors etc. The time spent will be returned tenfold when later on. I plan to release these components as open source as soon as they reach better and more stable performance (ie. production quality with documentation)

Lessons learned so far involves Dependecy properties which is very important if you'd like to develop custom controls in WPF. Animation control and triggers and getting more into DataBinding which looks very promising so far.

Links:
Recommended guidelines for WPF custom controls
Three ways to build an image button
Karl on WPF

Screenshot of the second prototype of the my GazeMemory game

Midas touch, Dwell time & WPF Custom controls

How do you make a distinction between users glancing at objects and fixations with the intention to start a function? This is the well known problem usually referred to as the "Midas touch problem". The interfaces that rely on gaze as the only means input must support this style of interaction and be capable of making distinction between glances when the user is just looking around and fixations with the intention to start a function.

There are some solutions to this. Frequently occurring is the concept of "dwell-time" where you can activate functions simply by a prolonged fixation of an icon/button/image. Usually in the range of 4-500ms or so. This is a common solution when developing gaze interfaces for assistive technology for users suffering from Amyotrophic lateral sclerosis (ALS) or other "paralyzing" conditions where no other modality the gaze input can be used. It does come with some issues, the prolonged fixation means that the interaction is slower since the user has to sit through the dwell-time but mainly it adds stress to the interaction since everywhere you look seems to activate a function.

As part of my intention to develop a set of components for the interface a dwell-based interaction style should be supported. It may not be the best method but I do wish to have it in the drawer just to have the opportunity to evaluate it and perform experiments with it.

The solution I´ve started working on goes something like this; upon a fixation on the object an event is fired. The event launches a new thread which aims at determining if the fixation is within the area long enough for it to be considered to be a dwell (the gaze data is noisy) Half way through it measures if the area have received enough fixations to continue, otherwise aborts the thread. At the end it measures if fixations have resided within the area for more than 70% of the time, in that case, it activates the function.

Working with threads can be somewhat tricky and a some time for tweaking remains. In addition getting the interaction to feel right and suitable feedback is important. I'm investigating means of a) providing feedback on which object is selected b) indications that the dwell process has started and its state. c) animations to help the fixation to remain in the center of the object.

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Coding> Windows Presentation Foundation and Custom Controls

Other progress has been made in learning Windows Presentation Foundation (WPF) user interface development. The Microsoft Expression Blend is a tool that enables a graphical design of components. By creating generic objects such as gaze-buttons the overall process will benefit in the longer run. Instead of having all of the objects defined in a single file it is possible to break it into separate projects and later just include the component DLL file and use one line of code to include it in the design.

Additional styling and modification on the objects size can then be performed as if it were a default button. Furthermore, by creating dependency properties in the C# code behind each control/component specific functionality can be easily accessed from the main XAML design layout. It does take a bit longer to develop but will be worth it tenfold later on. More on this further on.

Microsoft Expression Blend. Good companion for WPF and XAML development.

Windows Presentation Foundation (WPF) has proven to be more flexible and useful than it seemed at fist glance. You can really do complex things swiftly with it. The following links have proven to be great resources for learning more about WPF.

Lee Brimelow, experienced developer who took part in the new Yahoo Messenger client. Excellent screencasts that takes you through the development process.
http://www.contentpresenter.com and http://www.thewpfblog.com

>Kirupa Chinnathambi, introduction to WPF, Blend and a nice blog.http://www.kirupa.com/blend_wpf/index.htm and http://blog.kirupa.com/

Microsoft MIX07, 72 hours of talks about the latest tools and tricks.http://sessions.visitmix.com/

Better feedback!

Since having a pointer representing the gaze position on the screen becomes distracting some other form of feedback is needed. As mentioned before having a pointer will cause your eyes to more or less automatically fixate on the moving object. Remember, the eyes are never still and even more the eye tracker does create additional jitter.

What we need is a subtle way of showing the user that the eye tracker has captured the gaze coordinates to the same location as he/she is looking at. It's time for trying to make it look a bit nicer than the previous example where the whole background color of the button would change on a gaze fixation.

The reason for choosing to work with Windows Presentation Foundation is that it provides rich functionality for building modern interfaces. For example you can define a trigger to an event, such as GazeEnter (ie. MouseEnter) on a button and then apply a build in graphical effect on the object. These effects are rendering in real time such as a glowing shadow around the object or a gaussian filter that gives the object an out of focus effect. Very useful for this project. Let's give it a try.

This is the "normal" button. Notice the out-of-focus effect on the globe in the center.

Upon receving a glance the event "Image.IsMouseOver" event is trigged. This starts the built-in rendering function BitmapEffect OuterGlowBitmapEffect which generates a nice red glowing border around the button.

The XAML design code (screenshot) for the button. Click to enlarge.
Notice the GlowColor and GlowSize attributes to manipulate the rendering of the effects.
To apply this to the button we define the element Style="{StaticResource GlowButton}" inside the button tag. Further the globe in the center can be brought back in focus and highlighed with a green glow surrounding it inside the button canvas.

The globe is defined as an image object. Upon focus the triggers will set the gaussian blur effect to zero, which means in focus. The glow effect produces the green circle surrounding the globe.

Putting it all together in a nice looking interface, using the Glass Window style, it looks promising and a real improvement since yesterdays boring interface. Providing a small surrounding glow of giving the image focus upon fixation is much better than changing the whole button color. The examples here are perhaps somewhat less subtle than they should, just to demonstrated the effect.

Screenshots of the second prototype with new U.I effects and events.

The "normal" screen with no gaze input.

OnGazeEnter. Generate a glowing border around the button

The other example with a green glow and the globe in full focus.