<title>Display optimization for visual information processing of continuous tone imagery</title>

Cathode ray tube (CRT) technology dominates the direct view display market. Mature CRT technology for many designs is still the preferred choice. CRT manufacturers have greatly improved the size and weight of the CRT displays. High performance CRTs continue to be in great demand, however, supply have to contend with the vanishing CRT vendor syndrome. Therefore, the vanishing CRT vendor syndrome fuels the search for an alternate display technology source. Within the past 10 years, field emission display (FED) technology had gained momentum and, at one time, was considered the most viable electronic display technology candidate [to replace the CRT]. The FED community had advocated and promised many advantages over active matrix liquid crystal displays (AMLCD), electro luminescent (EL) or Plasma displays. Some observers, including potential FED manufacturers and the Department of Defense, (especially the Defense Advanced Research Project Agency (DARPA)), consider the FED entry as having leapfrog potential. Despite major investments by US manufacturers as well as Asian manufacturers, reliability and manufacturing difficulties greatly slowed down the advancement of the technology. The FED manufacturing difficulties have caused many would-be FED manufacturing participants to abandon FED research. This paper will examine the trends, which are leading this nascent technology to its downfall. FED technology was once considered to have the potential to leapfrog over AMLCD's dominance in the display industry. At present the FED has suffered severe setbacks and there are very few [FED] manufacturers still pursuing research in the area. These companies have yet to deliver a display beyond the prototype stage.

This paper discusses the methods and results of a study which investigated image quality issues associated with transferring flight formats of a transport cockpit from a Cathode Ray Tube (CRT) to an Active Matrix Liquid Crystal Display (AMLCD). Eight subject pilots performed a series of flying tasks in two simulator sessions: one with a commercial grade CRT and the other with a commercial grade, prototype LCD. Subjective assessments were obtained via questionnaires that addressed image quality and useability issues. The results showed that the display formats could be implemented on the test LCD hardware with no significant degradation in image quality or usability. Some considerations for optimizing formats for LCD implementations are discussed.

Liquid Crystal on Silicon (LCOS) microdisplay combines high birefringence and low operating voltage liquid crystalline (LC) materials with crystalline silicon VLSI technology that provides a flexible technology to control and hold the state of the LC in a high resolution, small sized display [1]. The crystalline silicon VLSI technology is well recognized as a competitive alternative for active matrix liquid crystal display (AMLCD) [2]. Due to the low cost and compact system size achievable for display systems using LCOS technology, these devices have been integrated into camera view finders, head mount displays (HMD) [3], head-up-displays [4], and projection display systems such as front projector and rear projector for high definition televisions and computer monitors. The image quality of AMLCD is however limited by the electronic data write time since data is addressed by line-at-a-time, the display should not be viewed during the data write time to maintain good image contrast ratio. The loss of brightness due to the data write time is very detrimental for a single panel light engine with Field Sequential Color technique, where new image is updated at the frame rate of 180 Hz. The time to write the data (up to 1-2 milliseconds) becomes a significant fraction of the sub-frame time (5.5 milliseconds). Hence there is a serious brightness and contrast ratio tradeoff.

The present study was designed to examine the effects of illuminance and color temperature of room lighting. Four male students volunteered as subjects. Each of them performed a calculation task for 95 minutes under nine different lighting environments consisting of a combination of three levels of illuminance (320lx, 1000lx and 2000lx) and three levels of color temperature (3000 degrees K, 5000 degrees K and 7500 degrees K). Three types of fluorescent lamps were used as a light source to vary the color temperature. Blood pressure, critical flicker frequency (CFF) and accommodation time of eye movements were measured every 30 minutes during the task. The accommodation time was significantly influenced by the illuminance level and both the relaxation time and contraction time were prolonged under 2000lx. The diastolic blood pressure was significantly affected by the color temperature level and increased under 7500 degrees K. As for the CFF, the interaction between illuminance and color temperature was significant. These results mean that not only the illuminance but also color temperature produces physiological effects. The present study may be the first to recognize the effect of color temperature on the blood pressure.

The U.S. Army/Boeing AH-64D Apache Longbow Attack Helicopter incorporates a new, highly integrated, avionics suite into the AH-64A airframe. The first 24 AH-64D Lot 1 production aircraft use monochrome cathode-ray tube (CRT) displays. Beginning in March 1998, all AH-64D aircraft have been delivered with color, active matrix liquid crystal displays (AMLCDs). This paper describes the avionics architecture alternative that were evaluated, and the selected architecture for the new flat panel display integration into the AH-64D aircraft.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

This paper presents the recent developments in our Active Matrix Liquid Crystal Displays for military, avionic and automotive applications. Data is presented for PIN diode driven active matrix liquid crystal display, with full color and high resolution (164 lines per inch). Optimization of color coordinates versus transmission has led us to better overall display performance. The contrast ratios were measured for various viewing angles (+/-60H and +45,-15 V) at different temperatures (-54 C to +85 C). The display shows good high ambient contrast ratio both by theoretical model and experimentally. The discrimination index model is used together with measurements to get the index for different high ambient light levels.

High yield and precisely controlled fabrication processes for large-size and high-resolution active-matrix liquid-crystal displays (AM-LCDs) have been established. By using these processes, the authors have developed two kinds of advanced AM-LCDs addressed by a-Si thin-film transistors: a high-resolution 5-in full-color AM LCD (240(V)*320*2(H) pixels) fabricated with an optimized color pixel arrangement; and a large-area, high-resolution 10-in. color Am-LCD (450(V)*640*3(H) pixels). These devices can replace the 5-in. conventional CRT TVs and 12-in. CRT display monitors currently used. These AM LCDs will also allow such applications as hand-held and laptop personal computers in the near future.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

The characteristics of natural light are mostly collected through specialized measuring equipment, such as a spectroradiometer, and some suggested measurement methods through a small RGB sensor. However, specialized measuring equipment presents difficulty in its high cost, and the RGB-sensor-based method has the limitation of being unable to measure the wavelength characteristics of natural light that are needed to implement lighting that supports circadian rhythms. This paper presents a method for calculating the short-wavelength-ratio-based color temperature of natural light in real time. First, an analysis of the correlation between the characteristics of natural light collected through a spectroradiometer was performed to determine the factors that were needed to accurately measure the color temperature of natural light. Then, the short-wavelength ratio of natural light was calculated through chromaticity coordinates (x and y), which are output values of the RGB sensor, and an equation for calculating the color temperature of natural light was derived through the short-wavelength ratio. Furthermore, after producing an RGB-sensor-based device, the derived equation was applied to calculate the color temperature of real-time natural light that reflects the wavelength characteristics. Then, as a result of the performance evaluation of the proposed method, the color temperature of natural light was accurately calculated within 1% of the average error rate.

Color image enhancement refers to improving the visual quality of color images by adjusting various attributes such as brightness, contrast, sharpness, and color balance. This enhancement aims to make the images more visually appealing, precise, and easier to interpret, often by accentuating essential features or details while minimizing noise or distortion. Techniques vary from simple adjustments of brightness and contrast to sophisticated algorithms. Effective image enhancement is crucial in numerous fields like medical imaging; enhancing the medical image is vital for accurate diagnosis and treatment planning, as well as remote sensing for improved satellite and aerial imagery. In security and surveillance, enhanced clarity in footage from surveillance cameras, especially in low-light scenarios, is crucial for identifying subjects and activities. However, image enhancement faces several challenges, like noise amplification and Over-enhancement, leading to unnatural-looking images with exaggerated or distorted features. In this paper, low-exposed or night color images are considered for enhancement, and this paper introduces exposure-based recursive histogram equalization techniques along with an Energy Curve instead of the conventional histogram; the energy curve is similar to a histogram based on spatial Contextual Information of an image. The proposed methods are Recursive Exposure-based Sub-image Histogram Equalization, Recursively Separated Exposure-based Sub-image Histogram Equalization, and Exposure-based Sub-image Histogram Equalization techniques considering spatial contextual information of images using an Energy Curve to improve results. These methods were tested on several publicly available datasetswith low-contrast color images and compared with HE, BBHE, DSHE, CLAHE, ESIHE, R-ESIHE, and RS-ESIHE. The proposed techniques are evaluated using parameterslikeAMBE, PSNR, MSE, Entropy, SSIM, and FSIM. The average PSNR values for eight images (taken from TeV DICeneter https://tev.fbk.eu/resources/imageenhancement) using the techniques mentioned above were 9.10817, 20.80568, 12.82645, 10.39347, 16.27458, 15.19979, and 14.59595, respectively. In contrast, the proposed ESIHE with Energy Curve achieved a PSNR of 22.31585, outperforming other methods across multiple metrics, particularly excelling in noise reduction (PSNR), error minimization (MSE: 193.44), structural similarity (SSIM: 0.733319), and feature retention (FSIM: 0.917678). The comparison demonstrates that enhancement methods can be significantly improved by considering spatial contextual information.

In this brief, simple analytical solutions for pre-emphasis driving conditions in active-matrix liquid crystal display (AMLCD) applications are presented. According to the solutions presented, the column driver with a gray-level dependent pre-emphasis (GLDP) function is designed for fast settling. The GLDP column driver is implemented without using additional frame memory. Also, modifications to the display system and integrated circuit fabrication process changes are not required. The GLDP column driver provides output voltage signals with variable pre-emphasis durations according to the magnitude of the gray-level shift to be driven. By applying the GLDP column driver, 8-mus reduction of the required one row line time was achieved on average. This one row line time reduction makes it possible to realize high performance and low cost AMLCDs. The 640 channel, full function GLDP column driver is fabricated by a 13.5-V 0.35-mum CMOS process.

Replacement of The ASQ-151, ASQ-175, and ASQ-184 monochrome cathode ray tube displays, used in the B-52 and B-1B, with flat panel displays will provide significant improvements in the reliability and maintainability of the display systems while improving the quality of the information viewed by the crew using these displays. This paper presents the process followed by USAF and Battelle (under the AIR Force Material Command's Design Engineering Program) to select the flat panel display technology to be fully developed during a preproduction prototype phase. Candidate flat panel display technologies evaluated included a color active matrix liquid crystal display, AC gas plasma panel display, and thin film electroluminescent display.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Color reproductions for LCD (Liquid Crystal Display) panels are different from that of CRT (Cathode Ray Tube) display. Color reproductions for a typical color LCD panel for personal computer (TFT transmissive type for Sharp Mebius MN930-X23) are examined. The reproduction color gamut on the (x,y) chromaticity diagram are measured by varying the input digital levels. The color reproduction area becomes smaller in accordance with the lower input digital level. The correlated color temperatures also vary with the input digital levels. The lower the input digital levels, the higher the correlated color temperatures. The method for making the correlated color temperature constant is shown in this paper. The gamma curves for three primary colors are modified to fix the correlated color temperatures. The compensation of the correlated color temperature has been confirmed on the LCD panel.

Automatic segmentation of the prostate of and the prostatic zones on MRI remains one of the most compelling research areas. While different image enhancement techniques are emerging as powerful tools for improving the performance of segmentation algorithms, their application still lacks consensus due to contrasting evidence regarding performance improvement and cross-model stability, further hampered by the inability to explain models’ predictions. Particularly, for prostate segmentation, the effectiveness of image enhancement on different Convolutional Neural Networks (CNN) remains largely unexplored. The present work introduces a novel image enhancement method, named RACLAHE, to enhance the performance of CNN models for segmenting the prostate’s gland and the prostatic zones. The improvement in performance and consistency across five CNN models (U-Net, U-Net++, U-Net3+, ResU-net and USE-NET) is compared against four popular image enhancement methods. Additionally, a methodology is proposed to explain, both quantitatively and qualitatively, the relation between saliency maps and ground truth probability maps. Overall, RACLAHE was the most consistent image enhancement algorithm in terms of performance improvement across CNN models with the mean increase in Dice Score ranging from 3 to 9% for the different prostatic regions, while achieving minimal inter-model variability. The integration of a feature driven methodology to explain the predictions after applying image enhancement methods, enables the development of a concrete, trustworthy automated pipeline for prostate segmentation on MR images.

: Aerospace and defense during the next few years will be dominated by the active matrix liquid crystal display, which became the preferred avionics displays technology in 1992. The trend just begun to replace electromechanical and cathode ray tube technologies with newer flat panel displays will accelerate in the 2000-2010 period as the commercial market continues its move towards digital flat television. Beyond 2010 high definition displays will begin to have a significant impact on fielded air fleets, with ultrahigh definition and even true three-D displays beyond 2020. By 2050 fully immersive cockpits may be anticipated for air and space vehicles and their simulators.

The development of a head mounted display concealed within eyeglasses has been a long term objective of many head-mounted display development efforts. This paper will review design concepts from the literature, with a view towardassessing the practical merits of the various approaches. The factors of importance in miniaturizing a head-mounted displaywill be summarized. Finally, we will briefly summarize some new approaches including the use of alternative displaytechnology that may lead to a display system hidden within eyeglasses frames.Key words: displays, HMDs, eyeglasses 1. INTRODUCTION This paper addresses the development of electronic mounted within eyeglasses. In this paper we shallrefer to such as eyeglasses-mounted displays (EMD). The ultimate goal of such work is the concealment of thedisplays, optics and wires within the eyeglass frame itself The development of an EMD requires the miniaturization ofhead mounted display technology, or possibly the development of new display and optical approaches. The key objective isto reduce the size of the hardware, while maintaining a large image size: this is a difficult problem upon which we will tryto place bounds. We will begin with a review of several concepts from the literature (including some interesting patents),and then consider the factors of importance in developing EMDs based on these and other concepts. Our review of theliterature and the discussion of approaches is not intended to be comprehensive; however, we will attempt to include adiscussion of several ofthe more difficult EMD challenges.The development of head-mounted (HMD) began with the helmet-mounted display, intended for militaryapplications. Helmet development has been proceeding for well over 20 years and has until recently utilized cathode raytubes (CRTs).1 The CRTs tended to limit the work to helmet-based systems owing to their size, weight and high voltageaspects. Recently HMD development has accelerated, owing to the development of a number of miniature flat paneldisplays that permit large reductions in system weight and complexity.2 There are two significant reasons for the earlyinterest specifically in helmet mounted displays. First, the helmets provided a large, rigid platform for mounting therequired optics and image sources. Second, and more importantly, there are many military and civilian applications inwhich helmets are needed and already carried. Thus, providing the user with a helmet modified to include a display has thepossibility that the helmet display system may not significantly add to the users burden. Our interest in EMDs is related tothis concept: provide the user with an augmentation of a device already carried to minimize the additional burden. Withoutthe large platform of the helmet, however, the technical problem becomes one of reducing the display and optical system tosizes that can be concealed within eyeglasses, but which still can provide the desired image.An examination of HMD system concepts shows the complexity inherent in generating an image of high quality.One of the principal requirements is the use of a miniature display2 and the first high quality goggle system to employ such