APSIPA Transactions on Signal and Information Processing > Vol 1 > Issue 1

Increasing image resolution on portable displays by subpixel rendering – a systematic overview

Lu Fang, Hong Kong University of Science and Technology, Hong Kong, fanglu922@gmail.com , Oscar C. Au, Hong Kong University of Science and Technology, Hong Kong, Ketan Tang, Hong Kong University of Science and Technology, Hong Kong, Xing Wen, Hong Kong University of Science and Technology, Hong Kong
 
Suggested Citation
Lu Fang, Oscar C. Au, Ketan Tang and Xing Wen (2012), "Increasing image resolution on portable displays by subpixel rendering – a systematic overview", APSIPA Transactions on Signal and Information Processing: Vol. 1: No. 1, e1. http://dx.doi.org/10.1017/ATSIP.2012.3

Publication Date: 28 Aug 2012
© 2012
 
Subjects
 
Keywords
Subpixel renderingdown-samplingfrequency analysis
 

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In this article:
I. SUBPIXEL ARRANGEMENTS IN LCD 
II. SUBPIXEL-BASED SPATIAL-DOMAIN ALGORITHM DESIGN 
III. SUBPIXEL-BASED FREQUENCY-DOMAIN ANALYSIS 
IV. CONCLUSION 

Abstract

Many of portable devices such as smart phones, portable multimedia players (PMP), and digital single-lens reflex (DSLR) cameras are capable of capturing high-resolution images (e.g. 10 mega-pixel in DSLR) or even video. The limited battery power supply in the portable devices often prevents these systems to use high-power large liquid crystal display (LCD). Instead, the portable devices often have a LCD screen with small physical size (e.g. 3 cm × 2 cm for Smartphone or DSLR) and with much lower pixel resolution (e.g. 0.15 mega-pixel for 480 × 320 display) than actual image/video resolution. Thus, the high-resolution image and video are down-sampled before being displayed. Unfortunately, the anti-aliasing filter often leads to rather severe blurring. Although the blurring may be minor when the viewing distance is large, it can be rather disturbing in portable applications due to the short viewing distance. To cope with the blurring problem, one possible solution is to use an LCD screen with higher resolution. But such hardware solution tends to be expensive and often not welcomed by the consumer electronic companies. Another possible solution is to continue to use the low-resolution LCD screen, but use some software technique to enhance the apparent image/video resolution. In this paper, we discuss a novel way to improve the apparent resolution of down-sampled image/video using a technique called subpixel rendering, which controls subpixel that is smaller than a pixel in a high-precision manner.

DOI:10.1017/ATSIP.2012.3