Image‐color‐quality modeling under various surround conditions for a 2‐in. mobile transmissive LCD

Abstract

Abstract— This study aims to develop an image‐color‐quality (ICQ) model for a 2‐in. mobile transmissive liquid‐crystal display (LCD). A hypothetical framework for ICQ judgment was made to visually assess ICQ based the cognitive processes of the human visual system (HVS), and then an illumination adaptive ICQ model applicable for various surround conditions was developed. The memory color reproduction ratio (MCRR) of a locally adapted region of interest in a complex image reproduced on a mobile display was first computed. The colorfulness index and luminance contrast for all of the pixels in the image were then calculated by a global adaptation process. Finally, an ICQ model including all of the three attributes was developed under dark conditions using an assessed set of psychophysical data. The model gave more accurate performance than the mean accuracy for all of the observers. It was also visually tested under three different outdoor conditions, including overcast, bright, and very bright conditions, and the illuminance level range was from 7000 to 35,000 to 70,000 lx. The effect of outdoor illumination could be quantified as an exponential decay function and the ICQ model could be extended to cover a wide variety of outdoor illuminations conditions.

It's not just the light

“…Most modern mobile devices have transmissive displays, which emit (as opposed to reflect) light [5], using either filtered backlighting or colour LEDs to produce an image. Due to the limited light production abilities of these displays, perceived image quality worsens as ambient light increases [25,26,30]. Other solutions for brighter displays have been introduced, such as Nokia's ClearBlack Display [14] and the One Glass Solution [20].…”

Designing for Situational Visual Impairments

“…The typical transmissive displays used in mobile devices require a backlight to display content on the screen [7]. Increasing ambient light reduces the image quality on the display [26,25,30] and the issue remains with newer screen technology, such as IPS and AMOLED displays [18]. Although anti-glare layers help, they can degrade image quality [40] and cause users to experience "visual sparkle", which is a perceived glittering effect on the display [8].…”

“…Our participants created a range of mobile content (28 participants designed more than one type of content); our participants reported 'Mobile friendly websites' (32), 'Mobile apps' (26), 'Advertising' (12), 'Games' (7), 'Books' (5), and 'Other' (4 -"data UI/UX" (P2), "brand identity" (P32), "branding, video graphics, magazines" (P41), and "Logo & Branding" (P43)).…”

Portable LCD Image Quality: Effects of Surround Luminance

“…Since various spatial frequency levels are mixed in a complex image, the masking phenomenon (Wandell, 1995;Kim et al, 2007) can occur and there might be some contrast loss detectable in unexpected frequencies. The masking commonly occurs in multi-resolution representations and there are cases when two spatial patterns S and S + ΔS cannot be discriminated, while ΔS seen alone, can be visible.…”