86,251 research outputs found
Blind Multimodal Quality Assessment of Low-light Images
Blind image quality assessment (BIQA) aims at automatically and accurately
forecasting objective scores for visual signals, which has been widely used to
monitor product and service quality in low-light applications, covering
smartphone photography, video surveillance, autonomous driving, etc. Recent
developments in this field are dominated by unimodal solutions inconsistent
with human subjective rating patterns, where human visual perception is
simultaneously reflected by multiple sensory information. In this article, we
present a unique blind multimodal quality assessment (BMQA) of low-light images
from subjective evaluation to objective score. To investigate the multimodal
mechanism, we first establish a multimodal low-light image quality (MLIQ)
database with authentic low-light distortions, containing image-text modality
pairs. Further, we specially design the key modules of BMQA, considering
multimodal quality representation, latent feature alignment and fusion, and
hybrid self-supervised and supervised learning. Extensive experiments show that
our BMQA yields state-of-the-art accuracy on the proposed MLIQ benchmark
database. In particular, we also build an independent single-image modality
Dark-4K database, which is used to verify its applicability and generalization
performance in mainstream unimodal applications. Qualitative and quantitative
results on Dark-4K show that BMQA achieves superior performance to existing
BIQA approaches as long as a pre-trained model is provided to generate text
description. The proposed framework and two databases as well as the collected
BIQA methods and evaluation metrics are made publicly available on here.Comment: 15 page
No-reference image quality assessment through the von Mises distribution
An innovative way of calculating the von Mises distribution (VMD) of image
entropy is introduced in this paper. The VMD's concentration parameter and some
fitness parameter that will be later defined, have been analyzed in the
experimental part for determining their suitability as a image quality
assessment measure in some particular distortions such as Gaussian blur or
additive Gaussian noise. To achieve such measure, the local R\'{e}nyi entropy
is calculated in four equally spaced orientations and used to determine the
parameters of the von Mises distribution of the image entropy. Considering
contextual images, experimental results after applying this model show that the
best-in-focus noise-free images are associated with the highest values for the
von Mises distribution concentration parameter and the highest approximation of
image data to the von Mises distribution model. Our defined von Misses fitness
parameter experimentally appears also as a suitable no-reference image quality
assessment indicator for no-contextual images.Comment: 29 pages, 11 figure
Testing QoE in Different 3D HDTV Technologies
The three dimensional (3D) display technology has started flooding the consumer television market. There is a number of different systems available with different marketing strategies and different advertised advantages. The main goal of the experiment described in this paper is to compare the systems in terms of achievable Quality of Experience (QoE) in different situations. The display systems considered are the liquid crystal display using polarized light and passive lightweight glasses for the separation of the left- and right-eye images, a plasma display with time multiplexed images and active shutter glasses and a projection system with time multiplexed images and active shutter glasses. As no standardized test methodology has been defined for testing of stereoscopic systems, we develop our own approach to testing different aspects of QoE on different systems without reference using semantic differential scales. We present an analysis of scores with respect to different phenomena under study and define which of the tested aspects can really express a difference in the performance of the considered display technologies
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