Conference Paper

Influence of chroma variations on naturalness and image quality of stereoscopic images.

DOI: 10.1117/12.817749 Conference: Human Vision and Electronic Imaging XIV - part of the IS&T-SPIE Electronic Imaging Symposium, San Jose, CA, USA, January 19-22, 2009, Proceedings
Source: DBLP

ABSTRACT The computational view on image quality of Janssen and Blommaert states
that the quality of an image is determined by the degree to which the
image is both useful (discriminability) and natural (identifiability).
This theory is tested by creating two manipulations. Firstly,
multiplication of the chroma values of each pixel with a constant in the
CIELab color space, i.e., chroma manipulation, is expected to increase
only the usefulness by increasing the distances between the individual
color points, enhancing the contrast. Secondly, introducing stereoscopic
depth by varying the screen disparity, i.e., depth manipulation, is
expected to increase both the usefulness and the naturalness. Twenty
participants assessed perceived image quality, perceived naturalness and
perceived depth of the manipulated versions of two natural scenes. The
results revealed a small, yet significant shift between image quality
and naturalness as a function of the chroma manipulation. In line with
previous research, preference in quality was shifted to higher chroma
values in comparison to preference in naturalness. Introducing depth
enhanced the naturalness scores, however, in contrast to our
expectations, not the image quality scores. It is argued that image
quality is not sufficient to evaluate the full experience of 3D. Image
quality appears to be only one of the attributes underlying the
naturalness of stereoscopic images.

Download full-text


Available from: Wijnand A Ijsselsteijn, Feb 26, 2014
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Because the chain of events in 3D imaging is vulnerable to different context- and technology-specific variables, it is important to understand the extent to which users can accept feature-specific differences between scenes without a decrease in the (observed) image quality. Twenty participants were asked to view natural stereoscopic still images and evaluate how different combinations of color asymmetries affect the overall viewing experience, the naturalness of the image and the depth perception. As expected, an increase in color asymmetry between the viewer’s left-eye and right-eye images decreased the image quality evaluation scores. Certain color-channel-specific changes, such as a decrease in blue values, were more acceptable than others, and some content-specific features, such as a brownish or greenish background, were less sensitive to changes compared to close-up images with brighter objects and backgrounds.
    Research in Science Education 05/2012; 3(5). DOI:10.1007/3DRes.02(2012)5 · 1.34 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Perceptual quality assessment is a challenging issue in three-dimensional (3D) signal processing research. It is important to study 3D signal directly instead of simple extension of the two-dimensional (2D) metrics directly to the 3D case as in some previous studies. In this paper, a new perceptual full-reference quality assessment metric of stereoscopic images is proposed by considering the binocular visual characteristics. The major technical contribution of the paper is that the binocular perception and combination properties are considered in quality assessment. To be more specific, we first perform left-right consistency check and compare matching error between the corresponding pixels in binocular disparity calculation, and classify the stereoscopic images into non-corresponding, binocular fusion and binocular suppression regions. Also, local phase and local amplitude maps are extracted from the original and distorted stereoscopic images as features in quality assessment. Then, each region is evaluated independently by considering its binocular perception property, and all evaluation results are integrated into an overall score. Besides, a binocular just noticeable difference (BJND) model is used to reflect the visual sensitivity for the binocular fusion and suppression regions. Experimental results show that compared with the relevant existing metrics, the proposed metric can achieve higher consistency with subjective assessment of stereoscopic images.
    IEEE Transactions on Image Processing 01/2013; 22(5). DOI:10.1109/TIP.2013.2240003 · 3.11 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this study is two-fold; first, to compare how certain visual aids contribute in depth estimation tasks on a portable autostereoscopic display; and second, how these depth cues impact on perceived quality. These were studied on a quantitative subjective study using a portable autostereoscopic display in controlled laboratory environment. Test participants evaluated object depths on three-dimensional images, where either 2D cues, 3D cues, or their combinations were provided. The study was conducted using three different compression levels in order to study how image quality affects the perception of depth. The results indicate that the depth estimation task is faster conducted when the participants relied on stereoscopic depth cues compared to situations where only monocular cues were present. Also, depth estimation task is faster conducted with higher quality images. Depth estimation accuracy was also higher with stereoscopic depth cues than with monocular ones. These results suggest that the human visual system can make more reliable depth estimates on portable autostereoscopic displays when stereoscopic cues are present. However, the results of the quality evaluations indicate that, as stated also on previous studies, the added stereoscopic depth does not seem to increase the subjective image quality.
    IEEE Journal of Selected Topics in Signal Processing 10/2012; 6(6):698-709. DOI:10.1109/JSTSP.2012.2208731 · 3.63 Impact Factor