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There have been few studies that empirically assess the perception of aesthetics in photography. This study addressed a few image attributes that were hypothesized to be important to the perception of aesthetics. Thirty consumer photographers evaluated 450 images in a repeated measures factorial experiment and provided artistic quality ratings on a 0 to 100-point scale. The image set balanced main...
We propose a method for perception evaluation of synchronization mismatch for large ultra high resolution tiled displays. The results from this work can help during design of low cost tiled display systems which utilize distributed synchronization mechanisms for image display. We describe a method for creation of synchronization mismatch measurement test video set for various tile configurations for...
This paper addresses the problem of perceptual quality measurement on individual coded video frames with distortions caused by both lossy source coding and lossy transmission. We focus on low bitrate H.264 coded video with error concealment and propagation due to packet losses. Identifying human visual system (HVS) masking effect as one of the most important factors affecting the perceptual quality,...
Recently, compression of high dynamic range (HDR) photography gained attention in the standardization of the Microsoft HDPhoto compression scheme as JPEG-XR. While integer data of 16 bits/pixel (bpp) in scRGB color-space can represent images up to a dynamic range of about 3.5 magnitudes in luminance - a noteworthy improvement over the 1.6 magnitudes possible in sRGB - even higher ranges are more efficiently...
Due to the required memory space and computing time, temporal processing is rarely used even in video processing. However, when the temporal aspect of a compression noise is major, it cannot be treated spatially only. The following article presents an example of such a noise: the mosquito noise. The equally spatial and temporal nature of the mosquito artifact is first explained through its definition...
For videos transmitted in an error-prone network, it is necessary to protect the source bitstream. Based on our packet loss visibility model, we minimize the end-to-end video quality degradation when transmitted in an AWGN channel using rate-compatible punctured convolutional codes for a given channel rate budget. We transform the original problem into a binary-decision problem, then we solve this...
In this paper we describe a database containing subjective assessment scores relative to 78 video streams encoded with H.264/AVC and corrupted by simulating the transmission over error-prone network. The data has been collected from 40 subjects at the premises of two academic institutions. Our goal is to provide a balanced and comprehensive database to enable reproducible research results in the field...
The most important step in the development process of a video quality metric is its verification with regards to the subjective quality experience. Even though guidelines in the form of standards and recommendations are well known, there are still quite often shortcomings in the verification process of many metrics. In this contribution we revisit these rules, point out important details and review...
Autostereoscopic displays simplify the presentation of 3D content because they do not require any glasses and they allow the perception of motion parallax. While the perception of depth is certainly an added value, the technical rendering process of the current display technology also introduces artifacts. For the viewer, the tradeoff may be expressed in terms of quality of experience. However, quality...
Full reference image quality indices assign a quality index to a pair of an undistorted reference image and a distorted image to be assessed; the quality of the index itself is then defined by its ability to predict the outcome of subjective tests performed by human observers judging the quality of the same image pair. In this article, a new DCT based image quality index is introduced whose complexity...
The past decades have witnessed the tremendous growth of digital image processing techniques for visual information representation and communication. Particularly, computational representation of perceived image quality has become a fundamental problem in computer vision and image processing. It is well known that the commonly used peak signal-to-noise ratio (PSNR), although analysis friendly, falls...
Recent VQM developments have provided a set of methods for evaluating the relative subjective quality of a treated video segment compared to the original video. In this paper we intend to optimize the subjective quality of multi-segment video sequence for a given global bitrate constraint, by adjusting some basic compression parameters such as the Quantization Parameter, the frame rate and the image...
Visibility thresholds play an important role in finding appropriate quantization step sizes in image and video compression systems. In this paper we present a new method of measuring visibility thresholds for quantization distortion in JPEG2000. A quantization distortion model for each subband is developed based on the statistical characteristics of wavelet coefficients and the dead-zone quantizer...
We propose to use two parameters, the scene complexity (C) and the level of motion (M), to capture the video content characteristics that matter most to the quality of compressed videos transmitted over IP networks, either with or without packet losses. Two simple but robust formulas are designed to calculate these two parameters from the following variables: bits of coded intra (I-) frames (BitsI...
In this paper, a no-reference objective sharpness metric based on a cumulative probability of blur detection is proposed. The metric is evaluated by taking into account the human visual system (HVS) response to blur distortions. The perceptual significance of the metric is validated through subjective experiments. It is shown that the proposed metric results in a very good correlation with subjective...
In this paper, we propose a new statistical objective perceptual video quality measure PSNRr,f-MOSr. PSNRr,f is defined as the PSNR achieved by f% of the frames in each one of the r% of the transmissions over a network. This quantity has the potential to capture the performance loss due to damaged frames in a particular video sequence (f%), as well asto indicate the probablity of a user experiencing...
Subjective testing is the most direct means of assessing audio, video, and multimedia quality as experienced by users and maximizing the information gathered while minimizing the number of trials is an important goal. We propose gradient ascent subjective testing (GAST) as an efficient way to locate optimizing sets of coding or transmission parameter values. GAST combines gradient ascent optimization...
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