We examined the image quality, image clarity, and viewing comfort of 2-D images rendered on an autostereoscopic display. Opinions on daily use of the content was gathered. Two different stereo displays were used in the experiments-a lenticular lens stereo display employing fixed 3-D stereo and a display with a switchable lenticular lens structure. Images were rendered on the displays with three different rendering schemes. Photos of natural scenes, artificial content, and content containing textual elements were used as the test stimuli. When images with natural scenes or artificial content were categorized into clusters according to the amount of details, significant differences in image quality, image clarity, and viewing comfort scores were observed. When two of the schemes were compared using the images containing textual elements, a significant difference in the viewing comfort and a significant increase in perceived stereoscopic depth impression were found with one of the schemes. Furthermore, image quality and viewing comfort were better with the 2-D display mode than with the 3-D mode. The use of the 2-D text content in the 3-D display mode seemed to be acceptable in general, but for longer term and repeated use, improvements in text quality should be considered. The results indicate that an increase in detail levels may decrease the evaluated image quality, clarity, and viewing comfort. Moreover, for all experimental conditions, better image quality, increased image clarity, and a more comfortable viewing experience had a positive influence on decisions of daily use.
We examined the image quality, image clarity and viewing comfort of the 2D images rendered on a fixed 3D
autostereoscopic display by using three different rendering schemes. Furthermore, opinions on the daily use of the
content were asked. The display used in the study had a lenticular lens as a stereo structure, and both photos of natural
scenes and artificial content were used as the test stimuli. Statistical analysis showed no significant differences between
the different schemes. When images were divided into subgroups according to the amount of details, significant
differences between image quality, image clarity, and viewing comfort scores were found. Moreover, the results indicate
that increase in detail levels may decrease evaluated image quality, clarity and viewing comfort. Finally, for all
experimental conditions better image quality, image clarity and more comfortable viewing experience had some positive
influence on decisions of daily use. In conclusion, amount of details in the content seem to affect on the user experiences
of 2D content shown on a 3D display.
We have developed a Near-to-Eye Display (NED) technology based on diffractive optics. Thin and highly transparent
plastic light guides enable a light-weight and ergonomic see-through NED design. We have previously reported of a
compact NED with an integrated gaze tracker. Eye gaze tracker can detect the user's focus point in the displayed image.
We have now made advances to further increase the level of integration as well as to enable the optical see-through.
Originally, three separate light guides were used: two for the display (red, green/blue) and one for infrared light of the
gaze tracker. To reduce weight and the system complexity, a shared light guide is now used for transmitting red (~630
nm, display) and infrared (~850 nm, gaze tracker) wavelengths. In addition, shared output gratings are used for outcoupling
the light. Light guide plates have been characterized by measuring their modulation transfer functions.
Measurements show that the deterioration of the NED's resolution, caused by the light guides, is reduced with improved
manufacturing techniques. Also, it has been verified that the additional gratings for infrared (light in-coupling and
expansion areas) do not have a notable effect on the display resolution.
Near-to-Eye Display (NED) offers a big screen experience to the user anywhere, anytime. It provides a way to perceive a
larger image than the physical device itself is. Commercially available NEDs tend to be quite bulky and uncomfortable
to wear. However, by using very thin plastic light guides with diffractive structures on the surfaces, many of the known
deficiencies can be notably reduced. These Exit Pupil Expander (EPE) light guides enable a thin, light, user friendly and
high performing see-through NED, which we have demonstrated. To be able to interact with the displayed UI efficiently,
we have also integrated a video-based gaze tracker into the NED. The narrow light beam of an infrared light source is
divided and expanded inside the same EPEs to produce wide collimated beams out from the EPE towards the eyes.
Miniature video camera images the cornea and eye gaze direction is accurately calculated by locating the pupil and the
glints of the infrared beams. After a simple and robust per-user calibration, the data from the highly integrated gaze
tracker reflects the user focus point in the displayed image which can be used as an input device for the NED system.
Realizable applications go from eye typing to playing games, and far beyond.
3D or autostereoscopic display technologies offer attractive solutions for enriching the multimedia experience. However,
both characterization and comparison of 3D displays have been challenging when the definitions for the consistent
measurement methods have been lacking and displays with similar specifications may appear quite different. Earlier we
have investigated how the optical properties of autostereoscopic (3D) displays can be objectively measured and what are
the main characteristics defining the perceived image quality. In this paper the discussion is extended to cover the
viewing freedom (VF) and the definition for the optimum viewing distance (OVD) is elaborated. VF is the volume inside
which the eyes have to be to see an acceptable 3D image. Characteristics limiting the VF space are proposed to be 3D
crosstalk, luminance difference and color difference. Since the 3D crosstalk can be presumed to be dominating the
quality of the end user experience and in our approach is forming the basis for the calculations of the other optical
parameters, the reliability of the 3D crosstalk measurements is investigated. Furthermore the effect on the derived VF
definition is evaluated. We have performed comparison 3D crosstalk measurements with different measurement device
apertures and the effect of different measurement geometry on the results on actual 3D displays is reported.