Date & Time : September 12 11:00 am - 12:30 pm Location : HS1 Chair : Tom Furness, HITLab, University of Washington Papers :
Performance and Sensitivity Analysis of INDICA: INteraction-free DIsplay CAlibration for Optical See-Through Head-Mounted Displays
Authors: Yuta Itoh, Gudrun Klinker
Abstract : An issue in AR applications with Optical See-Through Head-
Mounted Display (OST-HMD) is to correctly project 3D information
to the current viewpoint of the user. Manual calibration methods
give the projection as a black box which explains observed 2D-
3D relationships well (Fig. 1). Recently, we have proposed an
INteraction-free DIsplay CAlibration method (INDICA) for OSTHMD,
utilizing camera-based eye tracking[7]. It reformulates the
projection in two ways: a black box with an actual eye model (Recycle
Setup), and a combination of an explicit display model and an
eye model (Full Setup). Although we have shown the former performs
more stably than a repeated SPAAM calibration, we could
not yet prove whether the same holds for the Full Setup. More
importantly, it is still unclear how the error in the calibration parameters
affects the final results. Thus, the users can not know how
accurately they need to estimate each parameter in practice. We
provide: (1) the fact that the Full Setup performs as accurately as
the Recycle Setup under a marker-based display calibration, (2) an
error sensitivity analysis for both SPAAM and INDICA over the
on-/offline parameters, and (3) an investigation of the theoretical
sensitivity on an OST-HMD justified by the real measurements.
Analysing the Effects of a Wide Field of View Augmented Reality Display on Search Performance in Divided Attention Tasks
Authors: Naohiro Kishishita, Kiyoshi Kiyokawa, Ernst Kruijff, Jason Orlosky, Tomohiro Mashita, Haruo Takemura
Abstract : A wide field of view augmented reality display is a special type of head-worn
device that enables users to view augmentations in the peripheral visual
field. However, the actual effects of a wide field of view display on the
perception of augmentations have not been widely studied. To improve our
understanding of this type of display when conducting divided attention
search tasks, we conducted an in depth experiment testing two view management
methods, in-view and in-situ labelling. With in-view labelling, search target
annotations appear on the display border with a corresponding leader line,
whereas in-situ annotations appear without a leader line, as if they are
affixed to the referenced objects in the environment. Results show that
target discovery rates consistently drop with in-view labelling and increase
with in-situ labelling as display angle approaches 100 degrees of field of
view. Past this point, the performances of the two view management methods
begin to converge, suggesting equivalent discovery rates at approximately 130
degrees of field of view. Results also indicate that users exhibited lower
discovery rates for targets appearing in peripheral vision, and that there is
little impact of field of view on response time and mental workload.
SmartColor: Real-Time Color Correction and Contrast for Optical See-Through Head-Mounted Displays
Authors: Juan David Hincapié-Ramos, Levko Ivanchuk, Srikanth Kirshnamachari Sridharan, Pourang Irani
Abstract : Users of optical see-through head-mounted displays (OHMD) perceive color as a
blend of the display color and the background. Color-blending is a major
usability challenge as it leads to loss of color encodings and poor text
legibility. Color correction aims at mitigating color blending by producing
an alternative color which, when blended with the background, more closely
approaches the color originally intended. To date, approaches to color
correction do not yield optimal results or do not work in real-time. This
paper makes two contributions. First, we present QuickCorrection, a real-time
color correction algorithm based on display profiles. We describe the
algorithm, measure its accuracy and analyze two implementations for the
OpenGL graphics pipeline. Second, we present SmartColor, a middleware for
color management of user-interface components in OHMD. SmartColor uses color
correction to provide three management strategies: correction, contrast, and
show-up-on-contrast. Correction determines the alternate color which best
preserves the original color. Contrast determines the color which best
warranties text legibility while preserving as much of the original hue.
Show-up-on-contrast makes a component visible when a related component does
not have enough contrast to be legible. We describe the SmartColor’s
architecture and illustrate the color strategies for various types of display
content.
Minimizing Latency for Augmented Reality Displays: Frames Considered Harmful
Authors: Feng Zheng, Turner Whitted, Anselmo Lastra, Peter Lincoln, Andrei State, Andrew Maimone, Henry Fuchs
Abstract : We present initial results from a new image generation approach for
low-latency displays such as those needed in head-worn AR devices. Avoiding
the usual video interfaces, such as HDMI, we favor direct control of the
internal display technology. We illustrate our new approach with a bench-top
optical see-through AR proof-of-concept prototype that uses a Digital Light
Processing (DLP) projector whose Digital Micromirror Device (DMD) imaging
chip is directly controlled by a computer, similar to the way random access
memory is controlled. We show that a perceptually-continuous-tone dynamic
gray-scale image can be efficiently composed from a very rapid succession of
binary (partial) images, each calculated from the continuous-tone image
generated with the most recent tracking data. As the DMD projects only a
binary image at any moment, it cannot instantly display this latest
continuous-tone image, and conventional decomposition of a continuous-tone
image into binary time-division-multiplexed values would induce just the
latency we seek to avoid. Instead, our approach maintains an estimate of the
image the user currently perceives, and at every opportunity allowed by the
control circuitry, sets each binary DMD pixel to the value that will reduce
the difference between that user-perceived image and the newly generated
image from the latest tracking data. The resulting displayed binary image is
"neither here nor there," but always approaches the moving target that is the
constantly changing desired image, even when that image changes every 50µs.
We compare our experimental results with imagery from a conventional DLP
projector with similar internal speed, and demonstrate that AR overlays on a
moving object are more effective with this kind of low-latency display device
than with displays of similar speed that use a conventional video interface.