Content and quality

Abstract

Test image contents affect subjective image-quality evaluations. Psychometric methods might show that contents have an influence on image quality, but they do not tell what this influence is like, i.e., how the contents influence image quality. To obtain a holistic description of subjective image quality, we have used an interpretation-based quality (IBQ) estimation approach, which combines qualitative and quantitative methodology. The method enables simultaneous examination of psychometric results and the subjective meanings related to the perceived image-quality changes. In this way, the relationship between subjective feature detection, subjective preferences, and interpretations are revealed. We report a study that shows that different impressions are conveyed in five test image contents after similar sharpness variations. Thirty naïve observers classified and freely described the images after which magnitude estimation was used to verify that they distinguished the changes in the images. The data suggest that in the case of high image quality, the test image selection is crucial. If subjective evaluation is limited only to technical defects in test images, important subjective information of image-quality experience is lost. The approach described here can be used to examine image quality and it will help image scientists to evaluate their test images.

The Extended-OPQ Method for User-Centered Quality of Experience Evaluation: A Study for Mobile 3D Video Broadcasting over DVB-H

“…Recently, conventional psychoperceptual methods have been extended from hedonistic assessment towards measuring quality as a multidimensional construct of cognitive information assimilation or satisfaction constructed from enjoyment and subjective, but content-independent objective quality. Additional evaluations of the acceptance of quality act as an indicator of service-dependent minimum [ 23], ADAM [24], IVP [25,26] Mixed methods in multimedia quality research IBQ [27,28], Experienced Quality Factors [29] O P Q [ 10] [30 -33] (see overview in [20]). Furthermore, psychoperceptual evaluations are also extended from laboratory settings to evaluation in the natural contexts of use [9,[34][35][36][37].…”

“…The framework of data-driven analysis is applied and the outcome is described in the terms of the most commonly appearing characteristics [27,29,41,42].…”

“…Naïve test participants first sort a set of test stimuli into groups and then describe the characteristics of each group in an interview. Extending the idea of a free-sorting task, IBQ allows combining preference and description data in a mixed analysis to better understand preferences and the underlying quality factors in a level of a single stimulus [27].…”

The characteristic of image quality perception of elderly group: according to the comparison with adult group

“…In other words, the evaluation vocabularies that represent these cognitive attributes should be used in the image quality evaluation because images are accepted through visual and emotional cognitive properties as people are unfamiliar with the technical terms for image quality. Radum et al [31] derived the factors that influence the subjective preference of photography, and 'bright/sunny,' 'not sharp,' 'artistic,' 'real,' 'not shiny/dirty/not fresh,' 'sharp,' and 'shiny/clean/fresh' were derived as the factors that have immense influence on the image quality preference with 0.7 or higher Kappa coefficients. Based on these previous researches, a total of nine adjectives such as 'bright,' 'clean,' 'natural,' 'soft,' 'familiar,' 'sharp,' 'colorful,' 'realistic,' and 'image quality is good' were selected as the evaluation vocabularies for the subjective image quality evaluation test.…”

Quality Assessment in Video Surveillance

“…OPQ partly utilizes free sorting, as used in (Duplaga et al, 2008) but also applied in the method called Interpretation Based Quality (IBQ) (Nyman et al, 2006;Radun et al, 2008), adapted from (Faye et al, 2004;Picard et al, 2003). Unfortunately, these approaches allow mapping relational, rather than absolute, quality.…”