scholarly journals Adaptive luminance contrast for enhancing reading performance and visual comfort on smartphone displays

2014 ◽  
Vol 53 (11) ◽  
pp. 113102 ◽  
Author(s):  
Nooree Na ◽  
Hyeon-Jeong Suk
Keyword(s):  
Luminance Contrast ◽  
Reading Performance ◽  
Visual Comfort

Effects of Ambient Illumination, Luminance Contrast, and Stimulus Type on Subjective Preference of VDT Target and Background Color Combinations

2008 ◽  
Vol 107 (2) ◽  
pp. 336-352 ◽  
Author(s):  
Kong-King Shieh ◽  
Yen-Kung Lai
Keyword(s):  
Visual Display ◽  
Luminance Contrast ◽  
Visual Comfort ◽  
Background Color ◽  
Color Combination ◽  
Visual Display Terminal ◽  
Aesthetic Appearance ◽  
Subjective Preference ◽  
Color Combinations ◽  
Better Than

This study investigated the effects of the target and background color combination on subjective preference, i.e., aesthetic appearance, legibility and visual comfort, of stimuli presented on a visual display terminal under various ambient illuminations, luminance contrasts, and stimulus types. Analysis showed the main effect of color combination was significant for the three dependent variables. Black-on-white and blue-on-white were the most preferred combinations, while turquoise-on-green and turquoise-on-red were the least preferred. A sign was rated better than text. The significant interaction between color combination and luminance contrast indicated that more preferred color combinations were rated better under higher luminance contrast, whereas less preferred color combinations had better ratings under lower luminance contrast.

scholarly journals Luminance Contrast Assessment for Elderly Visual Comfort Using Imaging Measurements

2019 ◽  
Vol 32 ◽  
pp. 474-479 ◽  
Author(s):  
Estelle Guerry ◽  
Cătălin Daniel Gălățanu ◽  
Laurent Canale ◽  
Georges Zissis
Keyword(s):  
Luminance Contrast ◽  
Visual Comfort

scholarly journals The Effect of Colors and Positional Noise on Reading Performance with Non-words-Part 2

2021 ◽  
Vol 9 (B) ◽  
pp. 244-249
Author(s):  
Abdullah Alsalhi ◽  
Nadia Northway ◽  
Glyn Walsh ◽  
Abd Elaziz Mohamed Elmadina
Keyword(s):  
Letter Position ◽  
Reading Rate ◽  
Reading Performance ◽  
English Speakers ◽  
Horizontal Line ◽  
Visual Comfort ◽  
Poor Vision ◽  
Long Wavelength ◽  
Vertical Displacements ◽  
Distant Visual Acuity

BACKGROUND: Reading can be described as a complex cognitive process of decrypting signs to create meaning. Eventually, it is a way of language achievement, communication, and sharing of information and ideas. Changing lighting and color are known to improve visual comfort and the perceptual difficulties that affect reading for those with poor vision. AIM: The main objectives of the current study were to investigate the effect of changing the wavelengths and color with different levels of positional noise on reading performance with non-word for subjects with best-corrected distant visual acuity (BCVA) equal or better than 6/6. METHODOLOGY: In a cross-section interventional study, 20 English speakers were asked to read non-words presented in a printed format. The stimuli were black print words in a horizontal arrangement on a matte white card. They were degraded using positional noise produced by random vertical displacements of the letter position below or above the horizontal line on three levels. RESULTS: Introducing positional noise affected real and non-words recognition differently. The detrimental effects of positional noise with non-words on reading rate were not influenced by changes in wavelengths and color. The long-wavelength reading rate resulted in the lowest performance compared with other wavelengths with all levels of noise. CONCLUSION: Reading performance is affected by changes in the levels of positional noise. However, the reading rate is not affected by changes in wavelength and color with non-words. The long-wavelength reading rate resulted in the lowest performance compared with other wavelengths and color with all levels of noise.

Inner contrast and perceptual quality in tasks with video display units

2001 ◽  
Vol 33 (3) ◽  
pp. 145-159 ◽  
Author(s):  
Beatriz M O’Donell Magister ◽  
Elisa M Colombo
Keyword(s):  
Luminance Contrast ◽  
Visual Performance ◽  
Perceptual Quality ◽  
Visual Comfort ◽  
Perceptual Response ◽  
Perceptual Contrast ◽  
Mean Luminance ◽  
Function Relationship ◽  
Performance Results ◽  
Video Display Units

The purpose of this paper is to find the physical luminance contrast of an image that best relates to perceptual quality in VDU achromatic tasks. The studies were carried out by measurement of visual performance, comfort judgements and contrast adjustment, taking into account different resolutions, polarities, background luminances and illuminance values. The results add a new piece of evidence about inner contrast as an appropriate criterion to describe perceptual contrast. Inner contrast also provides a satisfactory criterion for the optimum relation of luminances in inner details of characters. This paper shows that when the relation between suprathreshold perceptual response and stimulus magnitude - inner contrast - is plotted, the power function relationship is a curve that is concave downward; there is a compression of the perceptual response. Illuminance on the horizontal plane, within the experimental range (480 and 930 lux) is not a significant parameter. Background luminance is significant for comfort judgements and contrast adjustment trials, but not for visual performance results. Grey background and characters brighter than background seem to be preferred by the observers. Mean luminance contrasts higher than 5 are sufficient to reach a visual performance of 90% and good visual comfort. The corresponding inner contrast is 1.4.

Discriminant Validation of the Test of Reading Performance (TORP) for Identifying Children at Risk of Reading Difficulties

2000 ◽  
Vol 16 (2) ◽  
pp. 139-146 ◽  
Author(s):  
Padeliadu Susana ◽  
Georgios D. Sideridis
Keyword(s):  
At Risk ◽  
Elementary School Students ◽  
Reading Difficulties ◽  
Reading Performance ◽  
Low Achievers ◽  
Children At Risk ◽  
School Students ◽  
Students At Risk ◽  
Group A ◽  
The Mean

Abstract This study investigated the discriminant validation of the Test of Reading Performance (TORP), a new scale designed to evaluate the reading performance of elementary-school students. The sample consisted of 181 elementary-school students drawn from public elementary schools in northern Greece using stratified random procedures. The TORP was hypothesized to measure six constructs, namely: “letter knowledge,” “phoneme blending,” “word identification,” “syntax,” “morphology,” and “passage comprehension.” Using standard deviations (SD) from the mean, three groups of students were formed as follows: A group of low achievers in reading (N = 9) including students who scored between -1 and -1.5 SD from the mean of the group. A group of students at risk of reading difficulties (N = 6) including students who scored between -1.5 and -2 SDs below the mean of the group. A group of students at risk of serious reading difficulties (N = 6) including students who scored -2 or more SDs below the mean of the group. The rest of the students (no risk, N = 122) comprised the fourth group. Using discriminant analyses it was evaluated how well the linear combination of the 15 variables that comprised the TORP could discriminate students of different reading ability. Results indicated that correct classification rates for low achievers, those at risk for reading problems, those at risk of serious reading problems, and the no-risk group were 89%, 100%, 83%, and 97%, respectively. Evidence for partial validation of the TORP was provided through the use of confirmatory factor analysis and indices of sensitivity and specificity. It is concluded that the TORP can be ut ilized for the identification of children at risk for low achievement in reading. Analysis of the misclassified cases indicated that increased variability might have been responsible for the existing misclassification. More research is needed to determine the discriminant validation of TORP with samples of children with specific reading disabilities.

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