Seungyon Claire Lee

The performance of touch screen soft buttons

The introduction of a new generation of attractive touch screen-based devices raises many basic usability questions whose answers may influence future design and market direction. With a set of current mobile devices, we conducted three experiments focusing on one of the most basic interaction actions on touch screens: the operation of soft buttons. Issues investigated in this set of experiments include: a comparison of soft button and hard button performance; the impact of audio and vibrato-tactile feedback; the impact of different types of touch sensors on use, behavior, and performance; a quantitative comparison of finger and stylus operation; and an assessment of the impact of soft button sizes below the traditional 22 mm recommendation as well as below finger width.

American sign language recognition in game development for deaf children

CopyCat is an American Sign Language (ASL) game, which uses gesture recognition technology to help young deaf children practice ASL skills. We describe a brief history of the game, an overview of recent user studies, and the results of recent work on the problem of continuous, user-independent sign language recognition in classroom settings. Our database of signing samples was collected from user studies of deaf children playing aWizard of Oz version of the game at the Atlanta Area School for the Deaf (AASD). Our data set is characterized by disfluencies inherent in continuous signing, varied user characteristics including clothing and skin tones, and illumination changes in the classroom. The dataset consisted of 541 phrase samples and 1,959 individual sign samples of five children signing game phrases from a 22 word vocabulary. Our recognition approach uses color histogram adaptation for robust hand segmentation and tracking. The children wear small colored gloves with wireless accelerometers mounted on the back of their wrists. The hand shape information is combined with accelerometer data and used to train hidden Markov models for recognition. We evaluated our approach by using leave-one-out validation; this technique iterates through each child, training on data from four children and testing on the remaining childs data. We achieved average word accuracies per child ranging from 91.75% to 73.73% for the user-independent models.

Development of an American Sign Language game for deaf children

We present a design for an interactive American Sign Language game geared for language development for deaf children. In addition to work on game design, we show how Wizard of Oz techniques can be used to facilitate our work on ASL recognition. We report on two Wizard of Oz studies which demonstrate our technique and maximize our iterative design process. We also detail specific implications to the design raised from working with deaf children and possible solutions.

A gesture-based american sign language game for deaf children

We present a system designed to facilitate language development in deaf children. The children interact with a computer game using American Sign Language (ASL). The system consists of three parts: an ASL (gesture) recognition engine; an interactive, game-based interface; and an evaluation system. Using interactive, user-centered design and the results of two Wizard-of-Oz studies at Atlanta Area School for the Deaf, we present some unique insights into the spatial organization of interfaces for deaf children.

AirTouch: Synchronizing In-air Hand Gesture and On-body Tactile Feedback to Augment Mobile Gesture Interaction

We present the design and evaluation of Air Touch, a wristwatch interface that enables mobile gesture interaction through tactile feedback during limited visual attention conditions. Unlike its predecessor, the Gesture Watch, Air Touch is supported by a push-to-gesture mechanism (PTG) where the user performs a gesture and then confirms it afterward with a trigger gesture. The Gesture Watch, in contrast, requires the user to hold a trigger gesture while performing an interaction, and its PTG method does not allow the user to preview nor reverse the action. The effect of the new PTG mechanism and tactile feedback are evaluated through two experiments. The first experiment compares Air Touchs PTG mechanism to that of the Gesture Watch both with and without visual access to the watch. The second experiment examines mobile gesture interaction with the new PTG mechanism in four conditions (with and without tactile feedback and with and without visual restriction). We found that the new PTG mechanic enabled more accurate and faster interaction in the fully visible condition. Additionally, tactile feedback in the limited visual access condition successfully compensated for the lack of visual feedback, enabling similar performance times and perceived difficulties as in the fully visible condition without tactile feedback.

Automatic design of magazine covers

In this paper, we propose a system for automatic design of magazine covers that quantifies a number of concepts from art and aesthetics. Our solution to automatic design of this type of media has been shaped by input from professional designers, magazine art directors and editorial boards, and journalists. Consequently, a number of principles in design and rules in designing magazine covers are delineated. Several techniques are derived and employed in order to quantify and implement these principles and rules in the format of a software framework. At this stage, our framework divides the task of design into three main modules: layout of magazine cover elements, choice of color for masthead and cover lines, and typography of cover lines. Feedback from professional designers on our designs suggests that our results are congruent with their intuition.

Stop burdening your eyes: A wearable electro-tactile display

Mobile phone calls are often missed due to the user not hearing the phone ring or feeling it vibrate. We present the design of wearable textile-based electro-tactile display embedded in a wristband that can be integrated with current mobile phones and wearable computers. The display provides the user with an unobtrusive alert that is easy to distinguish. We explore several aspects of directional patterns for a design of electro-tactile stimulation while maintaining an appropriate form factor for a wristband.

Investigation of the role of aesthetics in differentiating between photographs taken by amateur and professional photographers

Automatically quantifying the aesthetic appeal of images is an interesting problem in computer science and image processing. In this paper, we incorporate aesthetic properties and convert them into computable image features for classifying photographs taken by amateur and professional photographers. In particular, color histograms, spatial edge distribution, and repetition identification are used as features. Results of experiments on professional and amateur photograph data sets confirm the discriminative power of these features.

Automatic design of colors for magazine covers

In the design of a magazine cover, making a set of decisions regarding the color distribution of the cover image and the colors of other graphical and textual elements is considered to be the concept of color design. This concept addresses a number of subjective challenges, specifically how to determine a set of colors that is aesthetically pleasing yet also contributes to the functionality of the design, the legibility of textual elements, and the stylistic consistency of the class of magazine. Our solution to automatic color design includes the quantification of these challenges by deploying a number of well-known color theories. These color theories span both color harmony and color semantics. The former includes a set of geometric structures that suggest which colors are in harmony together. The latter suggests a higher level of abstraction. Color semantics means to bridge sets of color combinations with color mood descriptors. For automatic design, we aim to deploy these two viewpoints by applying geometric structures for the design of text color and color semantics for the selection of cover images.

Document visual similarity measure for document search

Managing large document databases has become an important task. Being able to automatically compare document layouts and classify and search documents with respect to their visual appearance proves to be desirable in many applications. We propose a new algorithm that approximates a metric function between documents based on their visual similarity. The comparison is based only on the visual appearance of the document without taking into consideration its text content. We measure the similarity of single page documents with respect to distance functions between three document components: background, text, and saliency. Each document component is represented as a Gaussian mixture distribution; and distances between the components of different documents are calculated as an approximation of the Hellinger distance between corresponding distributions. Since the Hellinger distance obeys the triangle inequality, it proves to be favorable in the task of nearest neighbor search in a document database. Thus, the computation required to find similar documents in a document database can be significantly reduced.