Michiel Adriaanszoon Klompenhouwer

Subpixel image scaling for color‐matrix displays

The perceived resolution of matrix displays increases when the relative position of the color subpixels is taken into account. Subpixel-rendering algorithms are being used to convert an input image to subpixel-corrected display images. This paper deals with the consequences of the subpixel structure and the theoretical background of the resolution gain. We will show that this theory allows a low-cost implementation in an image scaler. This leads to high flexibility, allowing different subpixel arrangements and a simple control over the trade-off between perceived resolution and color errors.

51.1: Temporal Impulse Response and Bandwidth of Displays in Relation to Motion Blur

Displays with non-impulse temporal response suffer from motion blur artifacts. This paper will show that the temporal impulse response and related temporal bandwidth provide a simple and direct way to quantify motion blur.

An overview of flaws in emerging television displays and remedial video processing

New display principles aim at supreme image quality. The temporal aspects of these devices sometimes remain underexposed in the literature, and the paper presents an overview of new artifacts and possible remedies with signal processing. We discuss typical artifacts due to the unfavourable properties of emerging television displays. We introduce a processing model that eliminates or at least reduces the various artifacts that result from temporal imperfections of CRTs with alternative scanning, liquid crystal displays (LCDs), tiled displays, plasma display panels (PDPs), and colour sequential displays. We conclude that knowledge of the motion in the scene, i.e. motion estimation, is essential to at least partially repair the often unfavourable temporal behaviour of these displays. Such repair is realistic, as these displays have appeared on the market at the moment motion vector estimation has come to maturity for consumer applications.

54.1: Comparison of LCD Motion Blur Reduction Methods using Temporal Impulse Response and MPRT

This paper describes the relation between temporal display response and motion blur for several motion blur reduction methods (higher frame rate, scanning backlight, black data insertion). The impulse responses and Motion Picture Response Times (MPRTs) of these methods are calculated, compared and discussed.

13.4: Subpixel Image Scaling for Color Matrix Displays

The apparent resolution of matrix displays is increased when the relative position of the color subpixels is taken into account. This paper shows that a general method to achieve this for any subpixel arrangement, can be incorporated in an image scaler at low additional cost, allowing simple quality trade-off control.

48.1: LCD Motion Blur Reduction with Motion Compensated Inverse Filtering

Due to the sample-and-hold effect, LCDs suffer from motion blur even when the response of the panel is very fast. We present a video processing method called ‘motion compensated inverse filtering’, that allows reduction of this blur to a large extent, without modifying the display panel.

Spatio-Temporal Frequency Analysis of Motion Blur Reduction on LCDs

Liquid crystal displays (LCDs) are known to suffer from motion blur. In this paper, motion blur on LCDs is analyzed by examining the spatio-temporal spectrum of the perceived picture. This analysis is used to examine the performance of two motion blur reduction techniques: smooth frame insertion (SFI) and motion compensated up-conversion (MCU). The performance of both techniques is compared for TV applications.

43.2: More Realistic Colors from Small-Gamut Mobile Displays

New displays, like mobile LCDs and OLEDs, usually cannot show the primary colors (Red, Green, and Blue) required by the EBU-standard. Consequently, these displays have poor color rendition. This paper describes a relatively simple color-mapping algorithm that improves the color rendition of such displays considerably.

22.2: Dynamic Resolution: Motion Blur from Display and Camera

Over the past years, many improvements in display motion portrayal have been introduced. In particular the reduction of motion blur on LCDs has received much attention. In this paper, we analyze motion blur (dynamic resolution) from a system perspective, also taking into account the dynamic resolution of the recorded video.

Characterizing displays by their temporal aperture: A theoretical framework

— The spatio-temporal aperture and sample rate of a video display determines both the static and dynamic resolution of the video signal that is rendered. The dynamic display characteristics like the visibility of large-area flicker, motion judder, and motion blur can be derived from the frame rate and the temporal extent of the pixel aperture (i.e., the temporal aperture). For example, liquid-crystal displays (LCDs) have an aperture that is relatively small in the spatial dimension and wide in the temporal domain. Consequently, moving objects displayed on an LCD suffer from motion blur. Especially in TV applications, the temporal dimension has a large impact on the overall picture quality. The temporal aperture, together with the frame rate, is shown to predict the amount of perceived large-area flicker, motion judder, and motion blur and also the performance of motion-blur reduction algorithms for LCDs. From this analysis it is further determined how to obtain the optimal temporal aperture of a television display, for which not only properties of the human visual system (HVS), but also the properties of the video signal have to be taken into account.