1,366 research outputs found
Apparent sharpness of 3D video when one eye's view is more blurry.
When the images presented to each eye differ in sharpness, the fused percept remains relatively sharp. Here, we measure this effect by showing stereoscopic videos that have been blurred for one eye, or both eyes, and psychophysically determining when they appear equally sharp. For a range of blur magnitudes, the fused percept always appeared significantly sharper than the blurrier view. From these data, we investigate to what extent discarding high spatial frequencies from just one eye's view reduces the bandwidth necessary to transmit perceptually sharp 3D content. We conclude that relatively high-resolution video transmission has the most potential benefit from this method
Stereoscopic Omnidirectional Image Quality Assessment Based on Predictive Coding Theory
Objective quality assessment of stereoscopic omnidirectional images is a
challenging problem since it is influenced by multiple aspects such as
projection deformation, field of view (FoV) range, binocular vision, visual
comfort, etc. Existing studies show that classic 2D or 3D image quality
assessment (IQA) metrics are not able to perform well for stereoscopic
omnidirectional images. However, very few research works have focused on
evaluating the perceptual visual quality of omnidirectional images, especially
for stereoscopic omnidirectional images. In this paper, based on the predictive
coding theory of the human vision system (HVS), we propose a stereoscopic
omnidirectional image quality evaluator (SOIQE) to cope with the
characteristics of 3D 360-degree images. Two modules are involved in SOIQE:
predictive coding theory based binocular rivalry module and multi-view fusion
module. In the binocular rivalry module, we introduce predictive coding theory
to simulate the competition between high-level patterns and calculate the
similarity and rivalry dominance to obtain the quality scores of viewport
images. Moreover, we develop the multi-view fusion module to aggregate the
quality scores of viewport images with the help of both content weight and
location weight. The proposed SOIQE is a parametric model without necessary of
regression learning, which ensures its interpretability and generalization
performance. Experimental results on our published stereoscopic omnidirectional
image quality assessment database (SOLID) demonstrate that our proposed SOIQE
method outperforms state-of-the-art metrics. Furthermore, we also verify the
effectiveness of each proposed module on both public stereoscopic image
datasets and panoramic image datasets
3D fatigue from stereoscopic 3D video displays: Comparing objective and subjective tests using electroencephalography
The use of stereoscopic display has increased in recent times, with a growing range of applications using 3D videos for visual entertainment, data visualization, and medical applications. However, stereoscopic 3D video can lead to adverse reactions amongst some viewers, including visual fatigue, headache and nausea; such reactions can further lead to Visually Induced Motion Sickness (VIMS). Whilst motion sickness symptoms can occur from other types of visual displays, this paper investigates the rapid adjustment triggered by human pupils as a potential cause of 3D fatigue due to VIMS from stereoscopic 3D displays. Using Electroencephalogram (EEG) biosignals and eye blink tools to measure the 3D fatigue, a series of objective and subjective experiments were conducted to investigate the effect of stereoscopic 3D across a series of video sequences
Metrics for Stereoscopic Image Compression
Metrics for automatically predicting the compression settings for stereoscopic images, to minimize file size, while still maintaining an acceptable level of image quality are investigated. This research evaluates whether symmetric or asymmetric compression produces a better quality of stereoscopic image.
Initially, how Peak Signal to Noise Ratio (PSNR) measures the quality of varyingly compressed stereoscopic image pairs was investigated. Two trials with human subjects, following the ITU-R BT.500-11 Double Stimulus Continuous Quality Scale (DSCQS) were undertaken to measure the quality of symmetric and asymmetric stereoscopic image compression. Computational models of the Human Visual System (HVS) were then investigated and a new stereoscopic image quality metric designed and implemented. The metric point matches regions of high spatial frequency between the left and right views of the stereo pair and accounts for HVS sensitivity to contrast and luminance changes in these regions.
The PSNR results show that symmetric, as opposed to asymmetric stereo image compression, produces significantly better results. The human factors trial suggested that in
general, symmetric compression of stereoscopic images should be used.
The new metric, Stereo Band Limited Contrast, has been demonstrated as a better predictor of human image quality preference than PSNR and can be used to predict
a perceptual threshold level for stereoscopic image compression. The threshold is the maximum compression that can be applied without the perceived image quality being
altered.
Overall, it is concluded that, symmetric, as opposed to asymmetric stereo image encoding, should be used for stereoscopic image compression. As PSNR measures of image
quality are correctly criticized for correlating poorly with perceived visual quality, the new HVS based metric was developed. This metric produces a useful threshold to provide a practical starting point to decide the level of compression to use
Perceived Acceleration in Stereoscopic Animation
In stereoscopic media, a sensation of depth is produced through the differences of images presented to the left and the right eyes. These differences are a result of binocular parallax caused by the separation of the cameras used to capture the scene. Creators of stereoscopic media face the challenge of producing compelling depth while restricting the amount of parallax to a comfortable range. Control of camera separation is a key manipulation to control parallax. Sometimes, stereoscopic warping is used in post-production process to selectively increase or decrease depth in certain regions of the image. However, mismatches between camera geometry and natural stereoscopic geometry can theoretically produce nonlinear distortions of perceived space. The relative expansion or compression of the stereoscopic space, in theory, should affect the perceived acceleration of objects moving through that space. This thesis suggests that viewers are tolerant of effects of distortions when perceiving acceleration in a stereoscopic scene
No-reference Stereoscopic Image Quality Assessment Using Natural Scene Statistics
We present two contributions in this work: (i) a bivariate generalized Gaussian distribution (BGGD) model for the joint distribution of luminance and disparity subband coefficients of natural stereoscopic scenes and (ii) a no-reference (NR) stereo image quality assessment algorithm based on the BGGD model. We first empirically show that a BGGD accurately models the joint distribution of luminance and disparity subband coefficients. We then show that the model parameters form good discriminatory features for NR quality assessment. Additionally, we rely on the previously established result that luminance and disparity subband coefficients of natural stereo scenes are correlated, and show that correlation also forms a good feature for NR quality assessment. These features are computed for both the left and right luminance-disparity pairs in the stereo image and consolidated into one feature vector per stereo pair. This feature set and the stereo pair׳s difference mean opinion score (DMOS) (labels) are used for supervised learning with a support vector machine (SVM). Support vector regression is used to estimate the perceptual quality of a test stereo image pair. The performance of the algorithm is evaluated over popular databases and shown to be competitive with the state-of-the-art no-reference quality assessment algorithms. Further, the strength of the proposed algorithm is demonstrated by its consistently good performance over both symmetric and asymmetric distortion types. Our algorithm is called Stereo QUality Evaluator (StereoQUE)
An Advanced, Three-Dimensional Plotting Library for Astronomy
We present a new, three-dimensional (3D) plotting library with advanced
features, and support for standard and enhanced display devices. The library -
S2PLOT - is written in C and can be used by C, C++ and FORTRAN programs on
GNU/Linux and Apple/OSX systems. S2PLOT draws objects in a 3D (x,y,z) Cartesian
space and the user interactively controls how this space is rendered at run
time. With a PGPLOT inspired interface, S2PLOT provides astronomers with
elegant techniques for displaying and exploring 3D data sets directly from
their program code, and the potential to use stereoscopic and dome display
devices. The S2PLOT architecture supports dynamic geometry and can be used to
plot time-evolving data sets, such as might be produced by simulation codes. In
this paper, we introduce S2PLOT to the astronomical community, describe its
potential applications, and present some example uses of the library.Comment: 12 pages, 10 eps figures (higher resolution versions available from
http://astronomy.swin.edu.au/s2plot/paperfigures). The S2PLOT library is
available for download from http://astronomy.swin.edu.au/s2plo
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