Development of the PenTile Matrix™ color AMLCD subpixel architecture and rendering algorithms

Abstract— Color subpixel rendering is enhanced by co‐optimizing the color subpixel architecture and algorithms with respect to human vision. This has resulted in the PenTile? display technology, which provides double the information content per subpixel when compared to a conventional RGB Stripe display. Output performance results from mathematical modeling, software simulations, and prototype AMLCDs displays demonstrate significant quality improvements to both text and full‐color images in comparison to images from RGB Stripe displays that have the same number of subpixels and column drivers.     

Aligning content rendering resolution and feature size with display capability in near‐eye display systems

In order to create a satisfying experience with near‐eye displays, the content must be adapted to be legible on the display used. New displays are using subpixel arrangements that can limit the minimum resolvable feature size to something greater than with the conventional RGB stripe arrangement. We conducted an experiment to measure the minimum and preferred size of text in two virtual reality (VR) displays systems and find that the text size is display limited. We then measure several displays with different pixel arrangements to determine whether the subpixel arrangement could impact legibility. We propose several Fourier metrics that can be computed from the measured data to categorize the capability of the display and describe a framework for selecting the appropriate content from a set of discrete tiers.     

基于气门油封的亚像素边缘检测

针对气门油封的尺寸检测问题, 本文提出了一种基于Zernike矩改进算法的亚像素边缘检测方法. 首先, 对比分析了高斯滤波和双边滤波的预处理效果, 结果表明双边滤波在滤波和保留边缘信息方面具有更好的表现. 然后, 采用Canny算子进行边缘粗定位, 并利用自适应的Zernike矩过度模型进行亚像素级定位. 最后, 采用最小二乘拟合圆法获取圆心坐标和半径. 经试验证明, 优化后算法的边缘定位平均误差更小, 精度更加准确.     

DIA‐PDP with high luminous efficacy and increased vertical resolution

Abstract— A PDP utilizing a new cell configuration to improve the vertical resolution and luminous efficacy is proposed. In this configuration, a delta subpixel arrangement is adopted because it reduces the vertical pixel pitch by half and increases the vertical resolution. In this configuration, R, G, B subpixels form triangles which are diamond shaped, the rational for calling this technology “DIAPDP.” High luminous efficacy is achieved by reducing the reflectivity of the panel. The lower reflectivity enables increased transmittivity of the light‐reduction filter which is part of the PDP panel, thus ensuing sufficient contrast under bright conditions. The higher transmittivity increases the luminous efficacy with the filter. Results obtained for a 46‐in. panel demonstrate a 33% increase in the luminous efficacy when using the filter. The DIA cell configuration is further modified to be a “clustered DIA” in order to improve the color mixing. Through subjective evaluation, the color mixing was compared with that of panels based on a trio subpixel arrangement and DIA, and the effect on color mixing was confirmed. The luminous efficacy of clustered DIA is also shown to be equal to that of DIA.     

Effects of display method,number of message lines,and text colour on Chinese comprehension and subjective preferences for an LED display

This study investigated the effects of display method, number of message lines and text colour on comprehension performance and subjective preferences for reading Chinese on a light‐emitting diode display. The factors and levels studied were: two text display methods (rapid serial visual presentation ‘rapid serial visual presentation (RSVP)’ and paged view scrolling), four numbers of message lines displayed at a time (one to four lines) and three text colours (amber, green and red). The RSVP method resulted in higher comprehension scores than the paged view scrolling method, and the green text produced better comprehension score than amber or red. However, the paged view scrolling received better subjective evaluation ratings than the RSVP method. A multiline display was found to be superior to a single‐line display for both comprehension scores and subjective evaluations. The results here provide useful ergonomics recommendations for choice of appropriate display method and format setting for presenting Chinese messages on light‐emitting diode displays.     

System considerations for RGBW OLED displays

Abstract— The fabrication of full‐color RGBW OLED displays using a white emitter with RGB color filters has been previously described. This paper discusses the effect of several display‐system factors on the important RGBW OLED display performance attributes of power consumption, lifetime, and perceived image quality. These display‐system factors include the spectrum of the white OLED, the white OLED structure, the color‐filter selection, the subpixel aperture ratios, and the pixel arrangement (including sub‐sampling).     

A new driving method to compensate for row‐line signal‐propagation delays in an AMLCD

Abstract— The row‐line and data‐line that make up of a TFT‐LCD panel can be modeled as a distributed resistance and capacitance network. As TFT‐LCD panels become larger and provide higher resolution, the induced signal propagation delay time from the row and column lines become an appreciable part of the line time. In particular, the row signal‐propagation delay time is traditionally accommodated by waiting for the worst‐case propagation time before the start of a new line. This conventional method, however, reduces the subpixel charging time. A new driving method, Horizontal Line Delay Compensation (H‐LDC), has been implemented and verified to compensate for row‐line propagation delay. The benefit of longer subpixel charging time is of particular interest to large‐area high‐resolution fast‐refresh‐rate LCD TVs.     

Low‐Cost Subpixel Rendering for Diverse Displays

Subpixel rendering increases the apparent display resolution by taking into account the subpixel structure of a given display. In essence, each subpixel is addressed individually, allowing the underlying signal to be sampled more densely. Unfortunately, naïve subpixel sampling introduces colour aliasing, as each subpixel only displays a specific colour (usually R, G and B subpixels are used). As previous work has shown, chromatic aliasing can be reduced significantly by taking the sensitivity of the human visual system into account. In this work, we find optimal filters for subpixel rendering for a diverse set of 1D and 2D subpixel layout patterns. We demonstrate that these optimal filters can be approximated well with analytical functions. We incorporate our filters into GPU‐based multi‐sample anti‐aliasing to yield subpixel rendering at a very low cost (1–2 ms filtering time at HD resolution). We also show that texture filtering can be adapted to perform efficient subpixel rendering. Finally, we analyse the findings of a user study we performed, which underpins the increased visual fidelity that can be achieved for diverse display layouts, by using our optimal filters.     

White‐emitting OLED devices in an RGBW format with microelement white subpixels

Abstract— OLED devices with an RGBW pixel format using an unpatterned white emitter have the potential to provide very good efficiency and color gamut while enabling lower‐cost and large‐format manufacturing. However, the white subpixel often has unacceptably large color shifts with viewing angle. Furthermore, for some architectures such as top‐emitting microcavity devices, it can even be difficult to produce a white subpixel with good on‐axis color. In this paper, we describe the use of a white subpixel made up of a combination of differently tuned microelements and demonstrate how such an approach can overcome these problems. By carefully tuning the color and areas of each of the microelements in the white subpixel, we can trade off between better on‐axis color, less color change with angle, and higher efficiency. Furthermore, it was demonstrated that an RGBW top‐emitter microcavity device with a microelement white subpixel can achieve an increase in both power efficiency and color gamut relative to a conventional RGBW bottom‐emitter non‐microcavity device.     

一种基于连通分量的文本区域定位方法

文本区域定位对复杂背景图像中的字符识别和检索具有重要意义。已有方法取得高的定位准确率和召回率,但效率较低,难以应用于实际的系统中。文中提出一种基于连通分量过滤和K-means聚类的文本区域定位方法。该方法首先对图像进行自适应分割,对字符颜色层提取连通分量。然后提取连通分量的特征,并用Adaboost分类器过滤非字符连通分量。最后,对候选的字符连通分量根据其位置和颜色层进行K-means聚类来定位文本区域。实验结果显示该方法具有与当前方法相当的准确率和召回率,同时具有较低的计算复杂度。     

A parallel computational approach for similarity search using Bloom filters

Finding similar items in a large and unstructured dataset is a challenging task in many applications of data science, such as searching, indexing, and retrieval. With the increasing data volume and demand for real time responses, similarity search has gained much consideration. In this paper, a parallel computational approach for similarity search using Bloom filters (PCASSB) has been proposed, which uses Bloom filter for the representation of features of document and comparison with user's query. Query features are stored in integer query array (^IQ_A), an array of integer. The PCASSB, an approximate similarity search technique, has been implemented on graphics processing unit with compute unified device architecture as the programming platform. To compute the similarity score between query and reference dataset, Dice coefficient has been used as a baseline method. The accuracy of the results generated by PCASSB is compared with the baseline method and other state‐of‐the‐art methods. The experimental results show that the proposed technique is quite effective in processing large number of text documents as it takes less computational time.     

Subpixel image scaling for color‐matrix displays

Abstract— 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.     

Fractional subpixel diffusion and fuzzy logic approach for ultrasound speckle reduction

Speckle is the dominant source of noise in ultrasound imaging and is a kind of multiplicative noise. It is difficult to design a filter to remove speckle effectively. In this paper, a novel fuzzy subpixel fractional partial difference (FSFPD) for ultrasound speckle reduction is proposed. Euler-Lagrange equation acts as an increasing function of the fractional derivative's absolute value of the image intensity function. The fractional order partial difference is computed in the frequency and fuzzy domain with subpixel precision. We test the proposed method on both synthetic and real breast ultrasound (BUS) images. The comparisons of the experimental results show that the proposed method can preserve edges and structural details of ultrasound images well while removing speckle noise. In addition, the filtered images are assessed and evaluated by radiologists using double blind method. The results demonstrate that the discrimination rate of breast cancers has been highly improved after employing the proposed method.     

Full‐color transflective cholesteric LCD with image‐enhanced reflector

Abstract— A full‐color bistable transflective cholesteric liquid‐crystal display (Ch‐LCD) was demonstrated by using an imbedded image‐enhanced reflector (IER) on top of each transmissive subpixel. The RGB colors were achieved by patterning conventional color filters on a black‐and‐white Ch‐LCD. In addition, the IER on top of each transmissive subpixel provides similar paths for the transmissive backlight and the reflected ambient light. A simple transflective Ch‐LCD was demonstrated.     

Multi‐view 3‐D display employing a flat‐panel display with slanted pixel arrangement

Abstract— A flat‐panel display with a slanted subpixel arrangement has been developed for a multi‐view three‐dimensional (3‐D) display. A set of 3M × N subpixels (M × N subpixels for each R, G, and B color) corresponds to one of the cylindrical lenses, which constitutes a lenticular lens, to construct each 3‐D pixel of a multi‐view display that offers M × N views. Subpixels of the same color in each 3‐D pixel have different horizontal positions, and the R, G, and B subpixels are repeated in the horizontal direction. In addition, the ray‐emitting areas of the subpixels within a 3‐D pixel are continuous in the horizontal direction for each color. One of the vertical edges of each subpixel has the same horizontal position as the opposite vertical edge of another subpixel of the same color. Cross‐talk among viewing zones is theoretically zero. This structure is suitable for providing a large number of views. A liquid‐crystal panel having this slanted subpixel arrangement was fabricated to construct a mobile 3‐D display with 16 views and a 3‐D resolution of 256 × 192. A 3‐D pixel is comprised of 12 × 4 subpixels (M = 4 and N = 4). The screen size was 2.57 in.     

A continuous‐viewing‐angle‐controllable liquid‐crystal display using a blue‐phase liquid crystal

Abstract— A continuous‐viewing‐angle‐controllable liquid‐crystal display (LCD) using a blue‐phase liquid crystal is proposed. To realize both wide‐viewing‐angle (WVA) mode and narrow‐viewing‐angle (NVA) mode with a single liquid‐crystal panel, each pixel is divided into a main pixel and a subpixel. The main pixel is for displaying images in both modes. The subpixel is for displaying images in WVA mode and controlling the viewing angle in NVA mode. The device exhibits a good viewing‐angle‐controlling characteristic and high transmittance.     

Investigating an application of speech‐to‐text recognition: a study on visual attention and learning behaviour

One major drawback of previous research on speech‐to‐text recognition (STR) is that most findings showing the effectiveness of STR for learning were based upon subjective evidence. Very few studies have used eye‐tracking techniques to investigate visual attention of students on STR‐generated text. Furthermore, not much attention was paid to learning differences, such as learning ability, learning style preferences and gender, to use STR texts. Therefore, this study carried out one experiment. Firstly, participants' visual attention on STR‐generated text was investigated by employing eye‐tracking technique. Secondly, how differently effective STR‐generated texts can be to influence participants' learning achievement was tested. Thirdly, this study compared visual attention and learning behaviour with the different characteristics of participants, such as learning ability, learning style preferences and gender, to use STR‐generated texts. Finally, this study explored students' perceptions regarding usefulness of STR‐generated texts for learning. This paper discusses results, research findings and implications along with conclusions and several suggestions for future development and research.     

A new process for the segmentation of high resolution remote sensing imagery

The “watershed transformation” is a well‐known powerful tool for automated image segmentation. However, it is often computationally expensive and can produce over‐segmentation in situations of high gradient noise, quantity error and detailed texture. Here, a new method has been designed to overcome these inherent drawbacks. After pre‐processing the imagery using a nonlinear filter in order to filter the noise, an optimized watershed transformation is applied to provide an initial segmentation result. Then, a multi‐scale, multi‐characteristic merging algorithm is used to refine the segmentation. Preliminary results show promise in term of both segmentation quality and computational efficiency.     

Development of performance‐ and cost‐oriented HD PDP TV with high picture quality using a high‐efficiency hexagonal array structure

Abstract— In this paper, we explained how we developed a 37‐in. plasma TV satisfying the major requirements of HDTV. For performance improvement, a HEXA cell structure in delta subpixel array was chosen. To improve picture quality, a subpixel rendering algorithm was added. Finally, to investigate the suitability for a single‐scan driver for cost reduction, the discharge characteristics were studied.