White Paper. Uniform Luminance Technology. What s inside? What is non-uniformity and noise in LCDs? Why is it a problem? How is it solved?
|
|
- William Byrd
- 5 years ago
- Views:
Transcription
1 White Paper Uniform Luminance Technology What s inside? What is non-uniformity and noise in LCDs? Why is it a problem? How is it solved? Tom Kimpe Manager Technology & Innovation Group Barco Medical Imaging Systems tom.kimpe@barco.com Barco Pres. Kennedypark 35 B-8500 Kortrijk, Belgium
2 ABSTRACT LCD technology has improved a lot in the past years. However, there are still some aspects that raise questions as to the usefulness of Liquid Crystal Displays for subtle clinical diagnosis. One major problem is the existence of luminance non-uniformities and color non-uniformities in medical displays. Several studies suggest that this nonuniformity can cause lower observer performance. Uniform Luminance Technology compensates for the non-uniformity and spatial noise. The result is a significant reduction of luminance non-uniformities and color nonuniformities. As an additional benefit, Uniform Luminance Technology ensures that the display is compliant with DICOM GSDF over its complete display area. Copyright 2005 BARCO n.v., Kortrijk, Belgium All rights reserved. No part of this publication may be reproduced in any form or by any means without written permission from Barco. Page 2 of 19
3 TABLE OF CONTENTS Table of contents 3 1 Non-uniformity and noise in LCDs? What is non-uniformity and spatial noise? Why is non-uniformity a problem? How to quantify non-uniformity? Solution for non-uniformity: Uniform Luminance Technology General compensation concept Real-time implementation Performance of Uniform Luminance Technology Luminance non-uniformity Color non-uniformity DICOM GSDF compliance Unique proprietary technology 18 5 Conclusions 18 6 References 19 Page 3 of 19
4 1 NON-UNIFORMITY AND NOISE IN LCDS? 1.1 What is non-uniformity and spatial noise? In medical LCD displays there are two types of noise: temporal noise and spatial noise. Temporal noise can be described as fluctuations over time, while spatial noise is a distortion over the display area that is stable in time. An example of temporal noise is the well-known phenomenon of flicker on a CRT display. Research [1, 2] has demonstrated that in LCD displays temporal noise plays a minor role, but that spatial noise can cause significant problems. An easy method to visualize spatial noise on LCDs is to look at a uniform image of a specific gray level. In case of a perfect display, we would perceive this image as being perfectly uniform and all of the display pixels would have the same luminance value. However, because of the spatial noise for example a typical luminance fall-off near the corners of the display is visible, but also many different shapes are possible. Figure 1: Typical noise pattern of a medical LCD There are several causes of this spatial noise. Non-uniformity of the backlight is responsible for the typical luminance fall-off towards the borders of the display. Backlight non-uniformities introduce a gradual roll-off towards the corner and are less disturbing to diagnostic precision. Of more concern are LCD cell artifacts causing higher frequency, pixel-by-pixel variations in the luminance of the display. Such artifacts are caused by tolerances on the storage capacitor of each LCD pixel, non-perfect rubbing of Page 4 of 19
5 the LCD alignment layer, tolerances in the conductivity of the column and row conductors, varying characteristics of the cell transistors, tolerances in the driver circuits. The superposition of all of these effects results in spatial noise, seen as a fixed, cloudy pattern on the LCD. LCD manufacturers refer this to as Mura. Spatial noise is sometimes called fixed pattern noise, because it is fixed in space (location) on the display and differs from temporal noise, as it will not vary as a function of time. High frequency spatial noise changes rapidly over the display area creating small pattern disturbances, whereas low frequency spatial noise varies slowly from place to place on the display and creates larger patterns. Figure 1 shows an example of a typical spatial noise pattern of medical LCDs. The scale used in this figure is percent. For example, a value of 80% at a location means that the luminance at that specific location is 80% of the mean luminance calculated over the complete display area. It is very important to note that the lower frequency noise patterns (that vary slowly over the display area) have much larger amplitude compared to the high frequency Gaussian noise. In other words: noise patterns that vary slowly over the display typically result in much higher distortion of the medical image than noise patterns that very rapidly. Figure 2: Spatial noise depends on the drive level (levels 64, 256 and 1023) One very important aspect of spatial noise in LCDs is that the noise pattern is stable over time but does depend on the image contents. Referring to the above-described causes such as the driving circuitry and the pixel transistors, it will be understandable that spatial noise does change as a function of drive level. This dependency of spatial noise on drive level can easily be seen from Figure 2, where the spatial noise pattern for the same display is shown at different drive levels (levels 64, 256 and 1023). Page 5 of 19
6 1.2 Why is non-uniformity a problem? Clinical relevance of luminance non-uniformity Spatial noise patterns are much more noticeable than the smallest difference in gray scales that can be displayed on the LCD. Therefore, these noise patterns can interfere with (subtle) features in the medical images that are being displayed. Original image Noise pattern introduced by display + Displayed image Figure 3: Effect of spatial noise on a medical image Page 6 of 19
7 Figure 3 illustrates this problem: the upper left image is the noise-free medical image that we would like to display. However the display suffers from spatial noise, which is shown in the upper right image. Therefore, the image that will actually be perceived by the radiologist is the sum of the original medical image and the noise pattern. This resulting image is shown in the lower part of figure 3. There are strong indications that this spatial noise can have a negative influence on the accuracy of medical diagnosis [3, 5]. It is well known that [4] the presence of noise makes it much harder for a human observer to discriminate a (subtle) image feature from the surrounding background. In other words: spatial noise increases the risk of false negatives (clinically relevant features that remain undetected). On the other hand, it is also possible that a human observer confuses the spatial noise pattern with a clinically relevant image feature. An example is that the spatial noise pattern of the display could be interpreted by a radiologist as actually being part of the medical image. Such confusion can result into false positives. Clinical relevance of color non-uniformity Since spatial noise is present in all LCD displays, it also impacts the performance of color displays. More and more color displays are being used in medical imaging. In some medical applications color is essential because it has a clinical meaning. Therefore, the precise reproduction of these colors is absolutely necessary. In color displays, spatial noise will not only result in luminance errors over the complete display area, but also in different color reproduction across the display area. In other words: the same color will look differently depending on the exact position on the display area. It is obvious that this is not acceptable for applications where precise color reproduction is important (such as PET/CT fused images). Page 7 of 19
8 Figure 4: Effect of spatial noise on accuracy of color reproduction Figure 4 gives an idea of the magnitude of the problem. Three colors were displayed on a color display. For each of the three colors the exact color coordinates were measured at multiple positions on the display area. If the color reproduction were perfect then Figure 4 would consist of only three points. Because of the spatial noise the color reproduction is dependent on the position on the display area. As can be, the measured differences are several times larger than the smallest color difference that a human observer can perceive (0.005 distance between color in the (x, y) diagram). DICOM-compliance In medical imaging compliance to DICOM GSDF [7] is very important, as it will guarantee that all grayscales in a medical image are effectively visible on the display and that the display is perceptually linear. Compliance to DICOM GSDF is achieved by calibrating the display system. With a photometer the exact transfer curve of the display is measured at one point on the display and then a Look-Up table is generated so that the display will follow the DICOM GSDF. Page 8 of 19
9 Figure 5: comparison of spatial noise at several video levels (video levels 64, 256, 512 and 1023) However, since all LCDs suffer from spatial noise, the DICOM calibration will only be correct for the exact location where the transfer curve was measured. This can be seen in Figure 5. In this figure, the spatial noise patterns of the same display are shown for different video levels (gray level 64, 256, 512 and 1023). It is obvious that the spatial noise patterns differ significantly for different video levels. This also means that the transfer curves for different positions on the display area are different. Consequently, if one only measures the transfer curve for one position on the display area, then the DICOM GSDF calibration will only be correct for that specific position on the display surface. Figure 6: DICOM GSDF compliance across the display surface Figure 6 confirms that the distortion (in JNDs) compared to the DICOM GSDF target is extremely large. This plot was created by first calibrating a display with a sensor in the Page 9 of 19
10 center of the display and then re-measuring the GSDF compliance at non-center display positions. The values in the plot show the average (over the 256 gray levels) distortion in Just Noticeable Differences (JNDs) compared to the target GSDF curve the display should follow at that position. In the center the display is well calibrated, since the sensor was placed there. On other display positions however the average distortion can range from a few JNDs to over 25 JNDs. It is obvious that such poor compliance to DICOM GSDF will result in much lower image quality. 1.3 How to quantify non-uniformity? Since the spatial noise pattern of a display depends on the drive level, there will be drive levels that have more non-uniformity than other drive levels and vice versa. Therefore, it is of no use to define a uniformity-metric of a display system based on measurement of one single drive level. A meaningful metric to quantify non-uniformity of a display system should take into account at least several driving levels, for example the 25%, 50%, 75% and 100% driving level. In Figure 7 the native display transfer curve (128 drive levels) is shown for multiple locations on the display surface. From this plot the peak-to-peak non-uniformity for each drive level can be read. This peak-to-peak non-uniformity corresponds to the difference between highest and lowest luminance value for a specific drive level. Figure 7: Display transfer curves for multiple locations Page 10 of 19
11 In order to come up with a single number that describes the non-uniformity of a display system, one could take the peak-to-peak non-uniformity averaged over a number of drive levels (such as 25%, 50%, 75%, 100%). 2 SOLUTION FOR NON-UNIFORMITY: UNIFORM LUMINANCE TECHNOLOGY 2.1 General compensation concept The general concept of Barco's Uniform Luminance Technology is explained in Figure 8. In a first step, the spatial noise pattern of the display is characterized for all video levels. Using this data, we calculate appropriate correction values for every display pixel and all video levels [2]. The Uniform Luminance Technology correction data is chosen so that it will compensate for the spatial noise of the LCD panel. Uniform Luminance Technology will digitally pre-compensate each image that needs to be displayed before sending it to the display panel. The correction data that is applied is the inverse of the spatial noise of the LCD. When this pre-compensated image is displayed, the stationary spatial noise and the digital pre-correction cancel out. Therefore, the overall perceived image is spatially noise-free. 2.2 Real-time implementation To make the Uniform Luminance Technology completely transparent for the user, we developed a real-time hardware implementation [6] inside the display. There is no need to install any extra software or application at all to benefit from the Uniform Luminance Technology. Everything is handled automatically by dedicated hardware inside the display. This highly complex hardware performs the required calculations at the frame-rate of the display, typically 60 frames per second. This guarantees that at all times the image shown on the display is fully Uniform Luminance Technology corrected. Because the correction is performed in real-time, there are absolutely no motion artifacts introduced by the Uniform Luminance Technology. Page 11 of 19
12 Original image Correction pattern introduced by Uniform Luminance Technology + Image sent to panel + Spatial noise pattern introduced by display Displayed image Figure 8: Concept of compensating for spatial noise Page 12 of 19
13 3 PERFORMANCE OF UNIFORM LUMINANCE TECHNOLOGY 3.1 Luminance non-uniformity Uniform Luminance Technology results in greatly improved luminance uniformity. Figure 9 compares the luminance uniformity (for video level 64) without and with Uniform Luminance Technology. Without Uniform Luminance Technology, luminance variations of over 40% are possible (luminance uniformity of less than 60%), whereas with Uniform Luminance Technology the luminance uniformity is increased to over 95%. As has been explained before, the spatial noise pattern of a display depends on the drive level. Therefore, to provide a true solution for spatial noise, it is necessary that the compensation algorithm uses a different correction pattern for each video level. This is exactly what Uniform Luminance Technology does. As an example, Figure 10 shows the luminance uniformity of the same display but for video level It becomes clear immediately that the spatial noise pattern for level 64 (Figure 9) and level 1023 (Figure 10) differ significantly. However, due to the fact that Uniform Luminance Technology uses a different correction image for each video level, it significantly increases uniformity for all video levels. Alternative uniformity enhancement techniques Other technologies that digitally optimize the uniformity of the backlight's luminance do exist. However, because these technologies use the same correction pattern for all video levels, they only provide optimal uniformity for one specific video level. Typically these algorithms are tuned to provide optimal bright uniformity (best uniformity at maximum video level or full white). However, because these algorithms use the same correction pattern for each video level (while the spatial noise pattern depends on the video level), there will still be significant non-uniformity at other drive levels. Page 13 of 19
14 Video level 6.25%, without Uniform Luminance Technology Video level 6.25%, With Uniform Luminance Technology Figure 9: Luminance uniformity without and with Uniform Luminance Technology (video level 6.25%) Page 14 of 19
15 Video level 100%, without Uniform Luminance Technology Video level 100%, with Uniform Luminance Technology Figure 10: Luminance uniformity without and with Uniform Luminance Technology (video level 100%) 3.2 Color non-uniformity In color displays, Uniform Luminance Technology not only improves luminance uniformity, but also color uniformity and color accuracy. To analyze the effect of Uniform Luminance Technology on color uniformity, three different colors were shown on the same display. For each of the three colors the exact Page 15 of 19
16 color coordinates were measured for multiple positions on the display surface. Figure 11 shows the results. Without Uniform Luminance Technology, there is a very large variation in color coordinates for the same color depending on the position on the display (left-hand side of Figure 11). This variation is much larger than the smallest difference in color that a human observer can perceive. without ULT with ULT Figure 11: Color uniformity without and with ULT The right-hand side of Figure 11 shows the same measurements, but with the Uniform Luminance Technology activated. With Uniform Luminance Technology the color variation over the display surface becomes much smaller and will typically be less than distance in (x,y)-space. This distance is the smallest difference in color that a human observer can perceive. Therefore, it is fair to say that Uniform Luminance Technology also significantly reduces color non-uniformity and results in more accurate color reproduction across the complete display area. 3.3 DICOM GSDF compliance Figure 12 shows the positive effect of Uniform Luminance Technology on DICOM GSDF compliance of LCDs. Without Uniform Luminance Technology, the display system will only be perfectly compliant to GSDF at the exact same position where the display was characterized. This can be seen on the left-hand side of figure 12. On a display system with Uniform Luminance Technology however, the display system will be compliant to DICOM GSDF across the entire display surface. Figure 12 also shows that the improvement is significant: without Uniform Luminance Technology, the average (over Page 16 of 19
17 256 video levels) distortion in JNDs compared to DICOM GSDF can be over 25 JNDs. With Uniform Luminance Technology, the DICOM GSDF compliance is as good for every location on the display surface and average distortion numbers are far below 1 JND. Figure 12: DICOM GSDF compliance without (left) and with (right) Uniform Luminance Technology. Note the difference in scale of the two plots. Right scale is 50x smaller. It is important to note that this improved compliance to DICOM GSDF is the result of making the display luminance uniform for every drive level. Other technologies that only digitally optimize the uniformity of the backlight's luminance exist. Such systems use the same correction pattern (typically the pattern for full white) for all video levels. Because the spatial noise pattern depends on the video level there will still be significant non-uniformity at other video levels. Such systems will therefore still suffer from different transfer curves for different locations on the display surface. Therefore, also compliance to DICOM GSDF will not be guaranteed except for exactly that position where the display was calibrated. Page 17 of 19
18 4 UNIQUE PROPRIETARY TECHNOLOGY Uniform Luminance Technology is a unique and proprietary Barco technology. Uniform Luminance Technology provides superior luminance uniformity and color uniformity and true DICOM GSDF compliance over the complete display surface. A unique aspect of Uniform Luminance Technology is that the technology simultaneously improves uniformity for all drive levels by using the appropriate correction images for each individual drive level. This is necessary because the spatial noise pattern of the display depends on the drive level. Alternative uniformity enhancement techniques Other technologies that optimize the uniformity of the backlight's luminance exist. These technologies use the same correction pattern for all drive levels and can only provide optimal uniformity for one specific video level (usually full white is chosen). Therefore significant non-uniformity remains for the other drive levels. As a result, technologies that only optimize the uniformity of the backlight's luminance also cannot provide compliance to DICOM GSDF across the entire display area. 5 CONCLUSIONS LCD technology has improved a lot over the past years, but there are still some aspects that raise questions as to the usefulness of Liquid Crystal Displays for subtle clinical diagnosis. One major problem is the existence of luminance non-uniformity and color non-uniformity in medical displays. Barco s Uniform Luminance Technology compensates for the non-uniformity and spatial noise. The result is a significant reduction of luminance non-uniformities and color nonuniformities. Because spatial noise depends on the drive level, Uniform Luminance Technology uses different correction images for every video level. Therefore, Uniform Luminance Technology also guarantees that the display is compliant with DICOM GSDF across its complete display area. Page 18 of 19
19 6 REFERENCES [1] Roehrig H, Krupinski EA, Chawla AS, Fan JH, Gandhi K. (2003). Spatial noise and threshold contrasts in LCD displays. SPIE Medical Imaging, Feb, San Diego, CA. [2] Solution for Nonuniformities and Spatial Noise in Medical LCD Displays by Using Pixel-Based Correction, Tom Kimpe et al, Journal of Digital Imaging, Springer New York, , vol. 18, no. 3, pp [3] A. Badano, S. J. Hipper, R. J. Jennings (2002), Luminance effect on display resolution and noise, Proceedings of the SPIE, Vol 4681, [4] E. Krupinski, H. Roehrig (2002). Pulmonary nodule detection and visual search: P45 and P104 monochrome versus color monitor displays, Academic Radiology, Vol 9, No. 6, [5] Roehrig H, Krupinski EA, Fan J, Chawla A, Gandhi K (2004). Physical and psychophysical evaluation of LCD noise. 18th International Computer Assisted Radiology & Surgery Conference, June, Chicago, IL [6] Solution for non-uniformities and spatial noise in medical LCD displays by using pixel-based correction, Tom Kimpe, Albert Xthona, Paul Matthijs and Lode De Paepe, Conference proceedings SCAR 2004, Hot topics session, May ,Vancouver, Canada [7] Digital Imaging and Communications in Medicine (DICOM), Supplement 28: Greyscale standard display function (GSDF), published by NEMA Page 19 of 19
Solution for Nonuniformities and Spatial Noise in Medical LCD Displays by Using Pixel-Based Correction
Solution for Nonuniformities and Spatial Noise in Medical LCD Displays by Using Pixel-Based Correction Tom Kimpe, Albert Xthona, Paul Matthijs, and Lode De Paepe Liquid crystal displays (LCD) are rapidly
More informationMonitor QA Management i model
Monitor QA Management i model 1/10 Monitor QA Management i model Table of Contents 1. Preface ------------------------------------------------------------------------------------------------------- 3 2.
More informationWhite Paper. Diagnostic Color Displays. What s inside?
White Paper Diagnostic Color Displays What s inside? Why is color becoming more important for diagnostic imaging? How does a color display work? What are the requirements of a diagnostic color display?
More informationWhite Paper. Missing Pixels in Medical Grayscale Flat Panel Displays. Geert Carrein Director Product Management. W hat s inside?
White Paper Missing Pixels in Medical Grayscale Flat Panel Displays W hat s inside? What are missing pixels? International Standards to characterize LCD quality Missing Pixels, overview for different LCD
More information3/2/2016. Medical Display Performance and Evaluation. Objectives. Outline
Medical Display Performance and Evaluation Mike Silosky, MS University of Colorado, School of Medicine Dept. of Radiology 1 Objectives Review display function, QA metrics, procedures, and guidance provided
More informationGuidelines for Assuring Softcopy Image Quality
Guidelines for Assuring Softcopy Image Quality What s inside? Quality Control Guidelines Softcopy QA testing and frequencies Danny Deroo Product and R&D Manager QA Products ABSTRACT To ensure diagnostic
More informationWhite Paper. In Plane Switching Pro technology for medical imaging. Geert Carrein Director Product Management. What s inside?
White Paper In Plane Switching Pro technology for medical imaging What s inside? An introduction to LCD technologies A primer on IPS-Pro Why is IPS-Pro LCD technology important for medical imaging? What
More informationDisplay Quality Assurance: Considerations When Establishing a Display QA Program. Mike Silosky, M.S. 8/3/2017
Display Quality Assurance: Considerations When Establishing a Display QA Program Mike Silosky, M.S. 8/3/2017 Objectives and Outline Why, Who, What, When, Where? Discuss the resources that may be needed
More informationWhat to consider when choosing a mammography display
What to consider when choosing a mammography display Screen size and resolution In digital breast imaging, the quality of the medical display has a direct impact on the decisions you make. Next to display
More informationCoronis Fusion multi-modality displays. The ultimate in diagnostic flexibility
Coronis Fusion multi-modality displays The ultimate in diagnostic flexibility The ultimate in diagnostic flexibility Radiology reading rooms are fast becoming one of the busiest departments in the healthcare
More informationCoronis 5MP Mammo. The standard of care for digital mammography
Coronis 5MP Mammo The standard of care for digital mammography The standard of care For thousands of women every day, details make all the difference. This understanding, along with many years of commitment
More informationOverview of All Pixel Circuits for Active Matrix Organic Light Emitting Diode (AMOLED)
Chapter 2 Overview of All Pixel Circuits for Active Matrix Organic Light Emitting Diode (AMOLED) ---------------------------------------------------------------------------------------------------------------
More informationColour Matching Technology
Colour Matching Technology For BVM-L Master Monitors www.sonybiz.net/monitors Colour Matching Technology BVM-L420/BVM-L230 LCD Master Monitors LCD Displays have come a long way from when they were first
More informationThis talk covers currently available display technology.
Introduction to Current Display Technologies for Medical Image Viewing Perspectives for the TG270 Update on Display Quality Control Alisa Walz-Flannigan, PhD (DABR) Mayo Clinic, Rochester, Minnesota AAPM
More informationDisplay Quality Assurance: Recommendations from AAPM TG270 for Tests, Tools, Patterns, and Performance Criteria
Display Quality Assurance: Recommendations from AAPM TG270 for Tests, Tools, Patterns, and Performance Criteria Nicholas B. Bevins, Ph.D. TG270 Co-chair Display Check 2 1 TG270 Goals Provide an update
More informationDisplay Quality Assurance: Recommendations from AAPM TG270 for Tests, Tools, Patterns, and Performance Criteria
Display Quality Assurance: Recommendations from AAPM TG270 for Tests, Tools, Patterns, and Performance Criteria Nicholas B. Bevins, Ph.D. TG270 Co-chair Display Check 2 TG270 Goals Provide an update to
More informationMammo Tomosynthesis 5MP
Mammo Tomosynthesis 5MP Display system for digital breast imaging Approved for TOMOSYNTHESIS MAMMOGRAPHY The standard of care For thousands of women every day, details make all the difference. This understanding
More informationMedical Imaging Working Group
Medical Imaging Working Group Czech Academy of Sciences Národní 3 117 20 Prague 1, Czech Republic 28 June 2017 Craig Revie, MIWG chair, opened the meeting at 10:45 and introduced the agenda as follows:
More informationOptimizing the Workflow of Radiologists
Clinical Performance That Matters Optimizing the Workflow of Radiologists www.barcomedical.com Meeting the Challenges of Today s Reading Rooms Radiology has long been at the epicenter of healthcare, with
More informationRole of Color in Telemedicine Applications. Elizabeth A. Krupinski, PhD
Role of Color in Telemedicine Applications Elizabeth A. Krupinski, PhD Background Color displays common clinical practice Radiology growing acceptance & use Other ologies & telemed routinely used No validated
More informationQuality Assurance (QA) Guidelines for Medical Imaging Display Systems
41-1 Japan Industries Association of Radiological Systems Standards (JESRA X-0093*A -2010 ) -English version- Enacted August 8, 2005 Revised June 11, 2010 Quality Assurance (QA) Guidelines for Medical
More information+ Human method is pattern recognition based upon multiple exposure to known samples.
Main content + Segmentation + Computer-aided detection + Data compression + Image facilities design + Human method is pattern recognition based upon multiple exposure to known samples. + We build up mental
More informationCoronis. A new generation of premium diagnostic display systems
Coronis A new generation of premium diagnostic display systems Diagnostic precision redefi ned Building on years of experience in state-of-the-art visualization, Barco has advanced medical imaging with
More informationUnderstanding PQR, DMOS, and PSNR Measurements
Understanding PQR, DMOS, and PSNR Measurements Introduction Compression systems and other video processing devices impact picture quality in various ways. Consumers quality expectations continue to rise
More informationContrast-Detail Characteristic Evaluations of Several Display Devices
Contrast-Detail Characteristic Evaluations of Several Display Devices Jihong Wang, Jon Anderson, Thomas Lane, Chess Stetson, and John Moore The contrast-detail characteristic of a display system is a powerful
More informationClarity and confidence. Raising the bar in diagnostic imaging with Barco radiology and mammography displays
Clarity and confidence Raising the bar in diagnostic imaging with Barco radiology and mammography displays Breaking new ground in healthcare imaging 1986 Barco s first medical display for ultrasound, MCD-10
More informationThe Lecture Contains: Frequency Response of the Human Visual System: Temporal Vision: Consequences of persistence of vision: Objectives_template
The Lecture Contains: Frequency Response of the Human Visual System: Temporal Vision: Consequences of persistence of vision: file:///d /...se%20(ganesh%20rana)/my%20course_ganesh%20rana/prof.%20sumana%20gupta/final%20dvsp/lecture8/8_1.htm[12/31/2015
More informationAustralian Dental Journal
Australian Dental Journal The official journal of the Australian Dental Association Australian Dental Journal 2012; 57:(1 Suppl): 16 23 doi: 10.1111/j.1834-7819.2011.01660.x The impact of computer display
More informationIntuitive Workflow by Barco. Designed for the way you work, naturally.
Intuitive Workflow by Barco Designed for the way you work, naturally. As the volume and complexity of patient exams continue to grow, radiologists face increasing demands to boost their productivity. Many
More informationA new technology for artifact free pattern stimulation
A new technology for artifact free pattern stimulation Jacques Charlier, Metrovision 1. Introduction stimulations are widely used in visual electrophysiology to obtain a response specific of ganglion cells:
More information15 medical monitor G15 MTIPH. Display Kungfu
15 medical monitor G15 is a 15 inch clinical display for endoscopy use, equipped with high resolution and high contrast, the images looks more clear and accurate and is displayed the least bit. All-around
More informationDevelopment of Simple-Matrix LCD Module for Motion Picture
Development of Simple-Matrix LCD Module for Motion Picture Kunihiko Yamamoto* Shinya Takahashi* Kouki Taniguchi* * A1203 Project Team Abstract A simple-matrix LCD module (12.1-in. SVGA) has been developed
More informationAn Alternative Architecture for High Performance Display R. W. Corrigan, B. R. Lang, D.A. LeHoty, P.A. Alioshin Silicon Light Machines, Sunnyvale, CA
R. W. Corrigan, B. R. Lang, D.A. LeHoty, P.A. Alioshin Silicon Light Machines, Sunnyvale, CA Abstract The Grating Light Valve (GLV ) technology is being used in an innovative system architecture to create
More informationPaper 21 Tel: Entered: July 14, 2015 UNITED STATES PATENT AND TRADEMARK OFFICE BEFORE THE PATENT TRIAL AND APPEAL BOARD
Trials@uspto.gov Paper 21 Tel: 571-272-7822 Entered: July 14, 2015 UNITED STATES PATENT AND TRADEMARK OFFICE BEFORE THE PATENT TRIAL AND APPEAL BOARD EIZO CORPORATION, Petitioner, v. BARCO N.V., Patent
More informationMX215. Your advantages. 2MP Medical-Display
MX215 Your advantages The EIZO MX215 features factory-preset DICOM tonal values and displays greyscale tones of radiological images in accordance with the requirements of the object. The advantage here
More informationDCI Requirements Image - Dynamics
DCI Requirements Image - Dynamics Matt Cowan Entertainment Technology Consultants www.etconsult.com Gamma 2.6 12 bit Luminance Coding Black level coding Post Production Implications Measurement Processes
More informationChapter 3 Evaluated Results of Conventional Pixel Circuit, Other Compensation Circuits and Proposed Pixel Circuits for Active Matrix Organic Light Emitting Diodes (AMOLEDs) -------------------------------------------------------------------------------------------------------
More informationNio. Industry-standard diagnostic display systems
Nio Industry-standard diagnostic display systems Diagnostic confidence in grayscale With the Nio diagnostic display system, Barco brings dependable diagnostic imaging to its true potential. Presenting
More informationTechNote: MuraTool CA: 1 2/9/00. Figure 1: High contrast fringe ring mura on a microdisplay
Mura: The Japanese word for blemish has been widely adopted by the display industry to describe almost all irregular luminosity variation defects in liquid crystal displays. Mura defects are caused by
More informationVeriLUM 5.2. Video Display Calibration And Conformance Tracking. IMAGE Smiths, Inc. P.O. Box 30928, Bethesda, MD USA
VeriLUM 5.2 Video Display Calibration And Conformance Tracking IMAGE Smiths, Inc. P.O. Box 30928, Bethesda, MD 20824 USA Voice: 240-395-1600 Fax: 240-395-1601 Web: www.image-smiths.com Technical Support
More informationColor measurement and calibration of professional display devices
White Paper Color measurement and calibration of professional display devices Abstract: With the advance of display technologies using LED light sources, the problems of color consistency, accuracy and
More informationAngular dependence of the luminance and contrast in medical monochrome liquid crystal displays
Angular dependence of the luminance and contrast in medical monochrome liquid crystal displays Aldo Badano a) Center for Devices and Radiological Health, Food and Drug Administration, 12720 Twinbrook Parkway,
More informationDCI Memorandum Regarding Direct View Displays
1. Introduction DCI Memorandum Regarding Direct View Displays Approved 27 June 2018 Digital Cinema Initiatives, LLC, Member Representatives Committee Direct view displays provide the potential for an improved
More informationHow to Match the Color Brightness of Automotive TFT-LCD Panels
Relative Luminance How to Match the Color Brightness of Automotive TFT-LCD Panels Introduction The need for gamma correction originated with the invention of CRT TV displays. The CRT uses an electron beam
More informationGuidance for Quality Assurance of PACS Diagnostic Display Devices
Guidance for Quality Assurance of PACS Diagnostic Display Programme NPFIT DOCUMENT RECORD ID KEY Sub-Prog / PACS Project NPFIT-PAC-DES-0042.06 Prog. Director Max Jones Owner Jerry Norman Version 1.0 Author
More informationBarco surgical displays. High-accuracy visualization solutions for surgery and endoscopy
Barco surgical displays High-accuracy visualization solutions for surgery and endoscopy Near-patient surgical displays The complexity of general and minimally invasive surgery places high demands on technology
More informationOPTIMAL TELEVISION SCANNING FORMAT FOR CRT-DISPLAYS
OPTIMAL TELEVISION SCANNING FORMAT FOR CRT-DISPLAYS Erwin B. Bellers, Ingrid E.J. Heynderickxy, Gerard de Haany, and Inge de Weerdy Philips Research Laboratories, Briarcliff Manor, USA yphilips Research
More informationHigh-resolution screens have become a mainstay on modern smartphones. Initial. Displays 3.1 LCD
3 Displays Figure 3.1. The University of Texas at Austin s Stallion Tiled Display, made up of 75 Dell 3007WPF LCDs with a total resolution of 307 megapixels (38400 8000 pixels) High-resolution screens
More informationIHE. Display Consistency Test Plan for Image Displays HIMMS and RSNA. Integrating the Healthcare Enterprise
HIMMS and RSNA IHE Integrating the Healthcare Enterprise Display Consistency Test Plan for Displays 2001-05-01 Marco Eichelberg 1, Klaus Kleber 2, Jörg Riesmeier 1, Adapted for IHE Year 3 by David Maffitt
More informationUsing Low-Cost Plasma Displays As Reference Monitors. Peter Putman, CTS, ISF President, ROAM Consulting LLC Editor/Publisher, HDTVexpert.
Using Low-Cost Plasma Displays As Reference Monitors Peter Putman, CTS, ISF President, ROAM Consulting LLC Editor/Publisher, HDTVexpert.com Time to Toss The CRT Advantages: CRTs can scan multiple resolutions
More informationCoronis Uniti (MDMC-12133) 12MP diagnostic display system for PACS and breast imaging
12MP diagnostic display system for PACS and breast imaging PACS and breast imaging on one display In grayscale and color (featuring unique color calibration!) With touch pad for fast control The only display
More informationEvaluation report. Eizo RadiForce G33-N 3MP greyscale flat panel liquid crystal display (LCD) CEP 07003
Evaluation report Eizo RadiForce G33-N 3MP greyscale flat panel liquid crystal display (LCD) CEP 07003 August 2007 Contents 2 Executive summary... 3 Introduction... 5 Product description... 6 Evaluation
More informationLCD and Plasma display technologies are promising solutions for large-format
Chapter 4 4. LCD and Plasma Display Characterization 4. Overview LCD and Plasma display technologies are promising solutions for large-format color displays. As these devices become more popular, display
More informationHEBS: Histogram Equalization for Backlight Scaling
HEBS: Histogram Equalization for Backlight Scaling Ali Iranli, Hanif Fatemi, Massoud Pedram University of Southern California Los Angeles CA March 2005 Motivation 10% 1% 11% 12% 12% 12% 6% 35% 1% 3% 16%
More informationLCD Motion Blur Reduced Using Subgradient Projection Algorithm
IOSR Journal of Electronics and Communication Engineering (IOSR-JECE) e-issn: 2278-2834,p-ISSN: 2278-8735 PP 05-11 www.iosrjournals.org LCD Motion Blur Reduced Using Subgradient Projection Algorithm Corresponding
More informationMTF measurement method for medical displays by using a bar-pattern image
MTF measurement method for medical displays by using a bar-pattern image Katsuhiro Ichikawa Yoshie Kodera Hiroshi Fujita Abstract A modulation-transfer-function (MTF) measurement method that uses a bar-pattern
More informationHospital Wide. Healthcare Display Solutions DICOM Displays, Large Screen Displays and Projectors
Hospital Wide Healthcare Display Solutions DICOM Displays, Large Screen Displays and Projectors THE WIDEST RANGE OF DISPLAY SOLUTIONS For Complete Hospital Wide Installations NEC offers a wide range of
More informationLecture 2 Video Formation and Representation
2013 Spring Term 1 Lecture 2 Video Formation and Representation Wen-Hsiao Peng ( 彭文孝 ) Multimedia Architecture and Processing Lab (MAPL) Department of Computer Science National Chiao Tung University 1
More informationDigital Logic Design: An Overview & Number Systems
Digital Logic Design: An Overview & Number Systems Analogue versus Digital Most of the quantities in nature that can be measured are continuous. Examples include Intensity of light during the day: The
More informationTechnology White Paper Plasma Displays. NEC Technologies Visual Systems Division
Technology White Paper Plasma Displays NEC Technologies Visual Systems Division May 1998 1 What is a Color Plasma Display Panel? The term Plasma refers to a flat panel display technology that utilizes
More informationID C10C: Flat Panel Display Basics
ID C10C: Flat Panel Display Basics Renesas Electronics America Inc. Robert Dunhouse, Display BU Engineering Manager 12 October 2010 Revision 1.1 Robert F. Dunhouse, Jr. Displays Applications Engineering
More informationPerformance Evaluation of Industrial Computed Radiography Image Display System
Performance Evaluation of Industrial Computed Radiography Image Display System More info about this article: http://www.ndt.net/?id=21169 Lakshminarayana Yenumula *, Rajesh V Acharya, Umesh Kumar, and
More informationCoronisUniti. User Guide MDMC ENABLING BRIGHT OUTCOMES
CoronisUniti User Guide MDMC-12133 ENABLING BRIGHT OUTCOMES Barco NV Beneluxpark 21, 8500 Kortrijk, Belgium www.barco.com/en/support www.barco.com Registered address: Barco NV President Kennedypark 35,
More informationDRAFT. Proposal to modify International Standard IEC
Imaging & Color Science Research & Product Development 2528 Waunona Way, Madison, WI 53713 (608) 222-0378 www.lumita.com Proposal to modify International Standard IEC 61947-1 Electronic projection Measurement
More informationStunning backdrops to captivate your audience Broadcast visualization solutions
Stunning backdrops to captivate your audience Broadcast visualization solutions Images taken seriously Offering the audience an ultimate viewing experience: that s the ambition of the broadcasting industry.
More informationUnderstanding Compression Technologies for HD and Megapixel Surveillance
When the security industry began the transition from using VHS tapes to hard disks for video surveillance storage, the question of how to compress and store video became a top consideration for video surveillance
More informationHigh Performance TFT LCD Driver ICs for Large-Size Displays
Name: Eugenie Ip Title: Technical Marketing Engineer Company: Solomon Systech Limited www.solomon-systech.com The TFT LCD market has rapidly evolved in the last decade, enabling the occurrence of large
More informationMX215. Your advantages. 2MP Medical-Display
MX215 Your advantages The EIZO MX215 features factory-preset DICOM tonal values and displays greyscale tones of radiological images in accordance with the requirements of the object. The advantage here
More informationAging display s effect on interpretation of digital pathology slides
Aging display s effect on interpretation of digital pathology slides Ali R. N. Avanakia, Kathryn S. Espiga, Sameer Sawhneyc, Liron Pantanowitzc, Anil V. Parwanic, Albert Xthonaa, Tom R. L. Kimpeb a Barco
More informationCalibration Best Practices
Calibration Best Practices for Manufacturers By Tom Schulte SpectraCal, Inc. 17544 Midvale Avenue N., Suite 100 Shoreline, WA 98133 (206) 420-7514 info@spectracal.com http://studio.spectracal.com Calibration
More informationFlat Panel Displays: LCD Technologies and Trends
Flat Panel Displays: LCD Technologies and Trends Robert Dunhouse, Sr. Engineering Manager, Display BU Class ID: 4C01B Renesas Electronics America Inc. Robert F. Dunhouse, Jr. Sr. Engineering Manager, Display
More informationIBM Research Report. Color and Luminance Management for High-Resolution Liquid-Crystal Displays
C68 (W-) December, Electrical Engineering IM esearch eport Color and Luminance Management for High-esolution Liquid-Crystal Displays Steven L. Wright, Steven E. Millman, Chai Wah Wu, Paul F. Greier IM
More informationQuantify. The Subjective. PQM: A New Quantitative Tool for Evaluating Display Design Options
PQM: A New Quantitative Tool for Evaluating Display Design Options Software, Electronics, and Mechanical Systems Laboratory 3M Optical Systems Division Jennifer F. Schumacher, John Van Derlofske, Brian
More informationCase Study: Can Video Quality Testing be Scripted?
1566 La Pradera Dr Campbell, CA 95008 www.videoclarity.com 408-379-6952 Case Study: Can Video Quality Testing be Scripted? Bill Reckwerdt, CTO Video Clarity, Inc. Version 1.0 A Video Clarity Case Study
More informationtechnical note flicker measurement display & lighting measurement
technical note flicker measurement display & lighting measurement Contents 1 Introduction... 3 1.1 Flicker... 3 1.2 Flicker images for LCD displays... 3 1.3 Causes of flicker... 3 2 Measuring high and
More informationPower Consumption Trends in Digital TVs produced since 2003
Power Consumption Trends in Digital TVs produced since 2003 Prepared by Darrell J. King And Ratcharit Ponoum TIAX LLC 35 Hartwell Avenue Lexington, MA 02421 TIAX Reference No. D0543 for Consumer Electronics
More informationRole of Color Processing in Display
Advances in Computational Sciences and Technology ISSN 0973-6107 Volume 10, Number 7 (2017) pp. 2183-2190 Research India Publications http://www.ripublication.com Role of Color Processing in Display Mani
More informationCommon assumptions in color characterization of projectors
Common assumptions in color characterization of projectors Arne Magnus Bakke 1, Jean-Baptiste Thomas 12, and Jérémie Gerhardt 3 1 Gjøvik university College, The Norwegian color research laboratory, Gjøvik,
More informationALIQUID CRYSTAL display (LCD) has been gradually
178 JOURNAL OF DISPLAY TECHNOLOGY, VOL. 6, NO. 5, MAY 2010 Local Blinking HDR LCD Systems for Fast MPRT With High Brightness LCDs Lin-Yao Liao, Chih-Wei Chen, and Yi-Pai Huang Abstract A new impulse-type
More information28 North Lotts, Dublin 1, Ireland Tel: info [AT] phonevolts.com
www.phonevolts.ie 28 North Lotts, Dublin 1, Ireland Tel: 01 8728722 Email: info [AT] phonevolts.com PhoneVolts is owned and operated by GSMsolutions.ie What is an LCD? A liquid crystal display (commonly
More informationSetup Guide. Color Volume Analysis Workflow. Rev. 1.2
Setup Guide Color Volume Analysis Workflow Rev. 1.2 Introduction Until the introduction of HDR, a video display s color reproduction range was typically represented with a two-dimensional chromaticity
More informationReimann et al: Perceptually Linear Display Devices 11
Reimann et al: Perceptually Linear Display Devices 11 [10] H.R. Blackwell. Contrast threshold of the human eye. Journal of the Optical Society of America, 36:624{643, November 1946. [11] A.A. Michelson.
More informationCoronis Fusion 6MP DL. 6 MegaPixel wide-screen diagnostic color display system
Coronis Fusion 6MP DL 6 MegaPixel wide-screen diagnostic color display system Live free Smart ideas can make a big difference. Sometimes, they can even change your view... That is exactly what Coronis
More informationModule 4: Video Sampling Rate Conversion Lecture 25: Scan rate doubling, Standards conversion. The Lecture Contains: Algorithm 1: Algorithm 2:
The Lecture Contains: Algorithm 1: Algorithm 2: STANDARDS CONVERSION file:///d /...0(Ganesh%20Rana)/MY%20COURSE_Ganesh%20Rana/Prof.%20Sumana%20Gupta/FINAL%20DVSP/lecture%2025/25_1.htm[12/31/2015 1:17:06
More informationSelf-Calibrating Wide Color Gamut High Dynamic Range Display
Self-Calibrating Wide Color Gamut High Dynamic Range Display Helge Seetzen 1/2, Samy Makki 1, Henry p 1, Thomas Wan 1/2, Vincent Kwong 1, Greg Ward 1, Wolfgang Heidrich 2, Lorne Whitehead 2 1 BrightSide
More informationCoronis 5MP Mammo. Online User Guide
Coronis 5MP Mammo Online User Guide (This page intentionally left blank.) 2 Table of contents Table of contents Using the online User Guide...4 Sources of information... 4 User interface... 4 Graphic board
More informationFFDM Quality Control in Canada - a Vendor Neutral Approach
FFDM Quality Control in Canada - a Vendor Neutral Approach Rasika Rajapakshe, PhD, FCCPM BC Cancer Agency-Center for the Southern Interior Kelowna, BC, Canada 2011 Joint AAPM/COMP Meeting August 4, 2011
More informationCoronis Fusion 6MP. User Guide MDCC-6230
Coronis Fusion 6MP User Guide MDCC-6230 K5902055/04 14/11/2014 Barco nv President Kennedypark 35, 8500 Kortrijk, Belgium Phone: +32 56.23.32.11 Fax: +32 56.26.22.62 Support: www.barco.com/esupport Visit
More informationInvestigation of Digital Signal Processing of High-speed DACs Signals for Settling Time Testing
Universal Journal of Electrical and Electronic Engineering 4(2): 67-72, 2016 DOI: 10.13189/ujeee.2016.040204 http://www.hrpub.org Investigation of Digital Signal Processing of High-speed DACs Signals for
More informationCoronis Uniti. See what you haven t seen before
Coronis Uniti See what you haven t seen before The facts The MarkeTech Group surveyed over 200 radiologists in Europe and North America to ask about the challenges in radiology. The key findings? About
More informationOn viewing distance and visual quality assessment in the age of Ultra High Definition TV
On viewing distance and visual quality assessment in the age of Ultra High Definition TV Patrick Le Callet, Marcus Barkowsky To cite this version: Patrick Le Callet, Marcus Barkowsky. On viewing distance
More informationEquipment Quality Control for Primary Displays June 5, Imaging Physics CancerCare Manitoba
Equipment Quality Control for Primary Displays June 5, 2018 Imaging Physics CancerCare Manitoba Purpose An equipment quality control (QC) program establishes baseline performance levels, tracks system
More informationWhite Paper JBL s LSR Principle, RMC (Room Mode Correction) and the Monitoring Environment by John Eargle. Introduction and Background:
White Paper JBL s LSR Principle, RMC (Room Mode Correction) and the Monitoring Environment by John Eargle Introduction and Background: Although a loudspeaker may measure flat on-axis under anechoic conditions,
More informationThe Diagnosis of Small Solitary Pulmonary Nodule:
The Diagnosis of Small Solitary Pulmonary Nodule: Comparison of Standard and Inverse Digital Images on a High-Resolution Monitor using ROC Analysis 1 Byeong-Kyoo Choi, M.D., In Sun Lee, M.D., Joon Beom
More informationGlobal Trade Medical Supplies
Features: Achieve Clarity True to the Source Data A medical monitor needs to be capable of high brightness in order to meet performance standards. However, in order to achieve high brightness in an LCD
More informationA Colorimetric Study of Spatial Uniformity in Projection Displays
A Colorimetric Study of Spatial Uniformity in Projection Displays Jean-Baptiste Thomas 1,2 and Arne Magnus Bakke 1 1 Gjøvik University College, The Norwegian Color Research Laboratory 2 Université de Bourgogne,
More informationThank you for your interest in BARCO s dedicated Home Theater products and more particular in our top-model, the CINE9.
D e a r H o m e T h e a t e r E n t h u s i a s t, Thank you for your interest in BARCO s dedicated Home Theater products and more particular in our top-model, the CINE9. Just like you, we always strive
More informationUNIVERSAL SPATIAL UP-SCALER WITH NONLINEAR EDGE ENHANCEMENT
UNIVERSAL SPATIAL UP-SCALER WITH NONLINEAR EDGE ENHANCEMENT Stefan Schiemenz, Christian Hentschel Brandenburg University of Technology, Cottbus, Germany ABSTRACT Spatial image resizing is an important
More informationThis paper is part of the following report: UNCLASSIFIED
UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADPO113 31 TITLE: Are the Color Gamuts of CRT and LCD Triangular? An Experimental Study DISTRIBUTION: Approved for public release,
More informationRX350. Your advantages. 3MP Medical-Display
RX350 Your advantages RadiForce RX350 features 3-megapixel resolution and high luminance perfect for precisely displaying radiological images. The device provides high image quality, advantageous for displaying
More information