High Pixel Count Research Articles

Paper No 6.1: Expectations for UHDTV Displays

AbstractUltra‐high definition television (UHDTV) intends to provide viewers with a better visual experience by giving them a strong sensation of reality by widening the field of view (FOV) of the image. A large pixel count is needed to widen the FOV while keeping the picture quality as high as that of HDTV. In particular, SUPER Hi‐VISION is or 8K‐UHDTV with 7680 × 4320 pixels. The development of the SUPER Hi‐VISION to date has given priority to achieving this high pixel count. It has resulted in a projector with four 4K liquid crystal on silicon (LCOS) devices, an 8K projector, an 85" liquid crystal display (LCD), and a 145" plasma display panel (PDP) with 7680 × 4320 pixels for each RGB color. Meanwhile, other parameters such as the frame frequency and colorimetry also improve the visual experience. After a thorough review of each system parameter, Recommendation ITU‐R BT.2020 was standardized. Besides the pixel count, it specifies a frame frequency, colorimetry, and bit depth beyond those of HDTV. A SUPER Hi‐VISION display should cover all of these parameters.

Spatially Resolved Thermal Conductivity Measurements Using a Thermoreflectance Microprobe

A transient thermoreflectance technique capable of creating maps of the out-of-plane thermal conductivity of materials with spatial resolution of 5 μm is presented. The applied noncontact optical microprobe uses a thin reflective metal film as temperature transducer and heat reservoir. The parameters of the experimental setup guarantee that the heat flow is one dimensional. Thus, relatively simple mathematical relations can be used to extract the thermal conductivity from the recorded signal shape, which is important for thermal conductivity maps with high pixel count. For reference materials (soda-lime glass and PbTe), the determined thermal conductivities were in good agreement with bulk values, indicating a typical measurement uncertainty of 10%. For low-conductivity substrates, the measuring scheme is relatively insensitive to thermal interface resistance. Thermal conductivity maps of lead-antimony-silver-tellurium surfaces showed distinct features which could be correlated with optical surface micrographs. The local conductivity fluctuations can possibly be attributed to local changes in chemical composition and secondary phase formation.

8K Extremely-High-Resolution Camera Systems

Research and development of ultrahigh-definition imaging systems that go beyond high-definition television (HDTV) have converged in the field of “4K” and “8K” imaging systems. The 4K imaging systems are used for digital cinema, while the 8K systems have been developed for use in next-generation TV broadcasting systems. The latter at 60 frames/s represents the highest pixel count and frame rate of any system, which includes their transmission design. In this paper, we will present an overview of two “8K” camera systems. One achieves a full resolution of 8K using three 33-Mpixel image sensors. The other is a more compact and practical camera system that uses four 8-Mpixel image sensors. We will also describe the camera functions, evaluation results, and views for future developments.

How Many Pixels Does It Take to Make a Good 4"×6" Print? Pixel Count Wars Revisited

Digital still cameras emerged following the introduction of the Sony Mavica analog prototype camera in 1981. These early cameras produced poor image quality and did not challenge film cameras for overall quality. By 1995 digital still cameras in expensive SLR formats had 6 mega-pixels and produced high quality images (with significant image processing). In 2005 significant improvement in image quality was apparent and lower prices for digital still cameras (DSCs) started a rapid decline in film usage and film camera sells. By 2010 film usage was mostly limited to professionals and the motion picture industry. The rise of DSCs was marked by a “pixel war” where the driving feature of the cameras was the pixel count where even moderate cost, ∼$120, DSCs would have 14 mega-pixels. The improvement of CMOS technology pushed this trend of lower prices and higher pixel counts. Only the single lens reflex cameras had large sensors and large pixels. The drive for smaller pixels hurt the quality aspects of the final image (sharpness, noise, speed, and exposure latitude). Only today are camera manufactures starting to reverse their course and producing DSCs with larger sensors and pixels. This paper will explore why larger pixels and sensors are key to the future of DSCs.

Image-based registration for synthetic aperture holography

High pixel count apertures for digital holography may be synthesized by scanning smaller aperture detector arrays. Characterization and compensation for registration errors in the detector array position and pitch and for phase instability between the reference and object field is a major challenge in scanned systems. We use a secondary sensor to monitor phase and image-based registration parameter estimators to demonstrate near diffraction-limited resolution from a 63.4 mm aperture synthesized by scanning a 5.28 mm subaperture over 144 transverse positions. We demonstrate 60 μm resolution at 2 m range.

Smart Two-Dimensional Laser-Based Display

In this paper, is proposed a smart design for a two-dimensional (2-D) optical display using 2-D laser scanning and an electronically programmable three-dimensional (3-D) beamforming lens element. Specifically, an electronically controlled variable focal length lens (ECVFL) adjusts its focus power to produce the smallest focused beam spot on the display screen within the designed variable screen distance range. Since the screen distance is known, the angular scan range for the scan mirrors can be computed to generate the desired number of scanned spots in the 2-D display. Thus a smart display with the smallest pixel spot size is formed leading to the highest spatial resolution display for any given distance. Furthermore, if the scan angles are increased, a larger size display of higher pixel count can be formed without sacrificing display pixel size at this larger display size. A proof-of-concept smart display optics system is designed and demonstrated for a red 633-nm laser wavelength and an optimal display variable screen distance of 20-150 cm, giving optimized display pixel sizes of 51.92 and 538.1 μm, respectively.

Digital holographic three-dimensional display of <inline-formula><math display="inline" overflow="scroll"><mrow><mn>50</mn><mtext>-</mtext><mi>Mpixel</mi></mrow></math></inline-formula> holograms using a two-axis scanning mirror device

The current limitation in pixel count of a single spatial light modulator SLM is one of the technological hurdles that must be over- come to produce a holographic 3-D display with a large image size. A conventional approach is to tile subholograms that are predivided from a reconfigurable computer-generated hologram CGH with a high pixel count. We develop a new approach to achieve a 50 Mpixel display by tiling reconstructed subholograms computed from a predivided 3-D ob- ject. The tiling is done using a two-axis scanning mirror device with a new tiling sequence. A shutterless system design is also implemented to enable effective tiling of subholograms. A high-speed digital micromirror device DMD at 6 kHz with 19201080 pixels is utilized to reconstruct the subholograms. Our current system shows the potential to tile up to 120 subholograms, which corresponds to about 240 Mpixels. The ap- proach we demonstrate gives a scalable solution to achieve a gigapixel- level display in the future. © 2010 Society of Photo-Optical Instrumentation

Tiled++: An Enhanced Tiled Hi-Res Display Wall

In recent years, high-resolution displays have become increasingly important to decision makers and scientists because large screens combined with a high pixel count facilitate content rich, simultaneous display of computer-generated imagery and high-definition video data from multiple sources. Tiled displays are attractive due to their extended screen real estate, scalability, and low cost. LCD panels are usually preferred over projectors because of their superior resolution. One of the drawbacks of LCD-based tiled displays is the fact that users sometimes get distracted by the screens' bezels, which cause discontinuities in rendered images, animations, or videos. Most conventional solutions either ignore the bezels and display all pixels, causing objects to become distorted, or eliminate the pixels that would normally fall under the bezels, causing pixels to be missing in the display of static images. In animations, the missing pixels will eventually reappear when the object moves, providing an experience that is similar to looking through a French window. In this paper, we present a new scalable approach that leads neither to discontinuities nor to significant loss of information. By projecting onto the bezels, we demonstrate that a combination of LCD-based tiled displays and projection significantly reduces the bezel problem. Our technique eliminates ambiguities that commonly occur on tiled displays in the fields of information visualization, visual data analysis, human-computer interaction, and scientific data display. It improves the usability of multimonitor systems by virtually eliminating the bezels. We describe a setup and provide results from an evaluation experiment conducted on a 3 x 3 and on a 10 x 5 tiled display wall.

Shaping the Display of the Future: The Effects of Display Size and Curvature on User Performance and Insights

ABSTRACT As display technology continues to improve, there will be an increasing diversity in the available display form factors and scales. Empirical evaluation of how display attributes affect user perceptions and performance can help designers understand the strengths and weaknesses of different display forms, provide guidance for effectively designing multiple display environments, and offer initial evidence for developing theories of ubiquitous display. Although previous research has shown user performance benefits when tiling multiple monitors to increase the number of pixels, little research has analyzed the performance and behavioral impacts of the form factors of much larger, high-resolution displays. This article presents two experiments in which user performance was evaluated on a high-resolution (96 DPI), high pixel-count (approximately 32 million pixels) display for single-user scenarios in both flat and curved forms. We show that for geospatial visual analytics tasks there is a benefit to larger displays, and a distinct advantage to curving the display to make all portions of the display more accessible to the user. In addition, we found that changing the form factor of the display does have an impact on user perceptions that will have to be considered as new display environments are developed.

Superresolution techniques for sun-sensor processing

We analyze the performance of conventional and parametric superresolution algorithms. Simulations provide quantitative comparisons of algorithm performance. In our tests, we study the effectiveness of parametric algorithms in sensors with differing noise characteristics, mask patterns, and detector resolutions. Parametric algorithms are less sensitive to increasing noise, and display dramatic improvements over conventional routines, but benefit only proportionally from higher pixel counts.

Deposition Pattern of Heliox-Driven Bronchodilator Aerosol in the Airways of Stable Asthmatics

To compare the deposition patterns of heliox-driven and air-driven radiolabeled bronchodilator aerosol, a prospective randomized study was undertaken at the Ben Taub Hospital in Houston, Texas. The working hypothesis was that nebulization with heliox would improve the peripheral deposition of a bronchodilator aerosol. Twelve mild-moderate known asthmatics were recruited for the study. They were asked to withhold medications for 8–24 hours prior to reporting for the study. Each subject was randomized to receive either heliox or oxygen for delivery of albuterol labeled with Tc-99m DTPA. Prior to the nebulization, baseline spirometry was performed. Following nebulization, the subjects were scanned for 1,000,000 counts on the ADAC Genesis Scanner. A postbronchodilator spirometry was then performed. Subjects returned about a week later, this time to have the same process repeated with the other gas. The normalized pixel counts were obtained, and the frequency distribution histograms were constructed for each of the deposition images. Skew and kurtosis were calculated. A lower skew and kurtosis value suggests a more peripheral distribution of the bronchodilator, whereas a higher pixel count corresponds with an increased area and uniformity of deposition. There were no statistically significant differences in baseline PFTs on the 2 days of the study. The pixel count was statistically higher after the heliox-driven nebulization than the air-driven nebulization. The skew and kurtosis values were lower after the heliox-driven nebulization than after the air-driven nebulization of radiolabeled aerosol. All patients had a good bronchodilator response with either driving gas. However, the degree of improvement was more with heliox-driven nebulization than with air-driven nebulization. We conclude that aerosol delivery with heliox results in more uniform and peripheral deposition. Thus, this mode of delivery can be used when uniform, peripheral deposition is desired as with drug delivery during an exacerbation or with aerosolized gene therapy.

Usefulness of positron-emission tomographic images after proton therapy

Purpose: To examine the positron emission tomography (PET) image obtained after proton irradiation and investigate the usefulness of the image for confirmation of the irradiated volume in proton radiotherapy (RT). Methods and Materials: A homogenous phantom was irradiated separately by carbon-ion and proton beams and the images obtained were compared. The PET images of cancer patients just after proton RT were then taken after informed consent. Results: In the PET image produced by carbon-ion beams, the high pixel counts in the image corresponded to the Bragg peak; however, in that produced by proton beams, they were visible throughout the entire track of the proton beams and were not related to the Bragg peak. The PET image of patients treated with proton RT was similar to that of the phantom experiment. Conclusion: The PET image after proton RT was different from that of carbon-ion RT. It was found that the PET image was very useful in proton RT to verify treatment planning.

Development of magnifying video endoscopes with high resolution

Background: The diagnostic capability of a video‐endoscope has been remarkably enhanced by using a high pixel count charge‐coupled device (CCD) and is getting closer to that of the stereomicroscope as its image quality is improved. From this standpoint, the authors have been developing high‐resolution magnifying video‐endoscopes.Methods: There are two methods available to increase the resolution of a video‐endoscope: (i) use a CCD with large pixel number and (ii) optically magnify the image impinging on the CCD. Since the video‐endoscope using a 410 Kilo (K) pixel count CCD was introduced in 1993, the authors have been developing a video‐endoscope using a large pixel count number CCD in pursuit of obtaining better image quality and resolution. Also, the technological innovations in CCD manufacturing have allowed CCDs to become much smaller in size with higher pixel numbers. As the CCD size decreases, the distal part of a video‐endoscope can be made thinner. With respect to optical magnification, two methods are available, the fixed close‐focusing system and variable focus.Results: With combined use of the variable focus magnification and the electronic magnification, a magnification more than × 100 can be achieved on a 14″ television monitor with higher resolution power and wider depth of field.Conclusions: The images captured by the latest magnifying video‐endoscope prove that the image quality of video‐endoscopy is improving and is approaching the diagnostic capability of the stereomicroscope.

34.1: Invited Paper: Microdisplays with High Pixel Counts

AbstractRecent developments in high‐resolution microdisplays are discussed. The importance of resolution limiting factors such as diffraction of light, fringe fields, voltage requirements and stepper field size is shown. Difficulties related to stitching and large‐area CMP are reviewed, Parallelism in the driver design is discussed and the first results of a 2560×2048 pixel microdisplay are presented.