Performance tests and quality control of cathode ray tube displays

Roehrig, Hans; Blume, Hartwig R.; Ji, Ting-Lan; Browne, M. T.

doi:10.1007/bf03167599

Cited by 38 publications

(18 citation statements)

References 9 publications

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“…Obviously the quality of a soft copy display (SD) system has a direct impact on the perceived image quality, and various components of an SD system can affect the performance of the human observer. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] An SD system typically includes a monitor (either CRT or LCD flatpanel) and a graphics control card. An SD system is more complex than a conventional film/lightbox (the hard copy) display system, and it has many varieties.…”

mentioning

confidence: 99%

Proposal of a Quality-Index or Metric for Soft Copy Display Systems: Contrast Sensitivity Study

Wang

Compton²,

Peng

2003

J Digit Imaging

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In addition to the inherent qualities of a digital image, the qualities of the monitor and graphics control card as well as the viewing conditions will affect the perceived quality of an image that is displayed on a soft copy display (SD) system. With the implementation of picture archiving and communication systems (PACS), many diagnoses are being made based on images displayed on SD devices, and consequently SD quality may affect the accuracy of diagnosis. Unlike the traditional film-on-lightbox display, optimal SD system parameters are not well defined, and many issues remain unsettled. In this article, the human observer performance, as measured by contrast sensitivity, for several SD devices including an active matrix liquid crystal flat panel monitor is reported. Contrast sensitivities were measured with various display system configurations. Experimental results showed that contrast sensitivity depends on many factors such as the type of monitor, the monitor brightness, and the gamma settings of the graphics card in a complex manner. However, there is a clear correlation between the measured contrast thresholds and the gradient of the display device's luminance response curve. Based on this correlation, it is proposed to use the gradient of luminance response curve as a quality-index or metric for SD devices.KEY WORDS: Soft copy display, contrast sensitivity, gradient of luminance response curve, display quality index, human observer performance A DISPLAY SYSTEM is the final link between the acquired image data and the eye-brain system of the human observer. Obviously the quality of a soft copy display (SD) system has a direct impact on the perceived image quality, and various components of an SD system can affect the performance of the human observer. 1-15 An SD system typically includes a monitor (either CRT or LCD flatpanel) and a graphics control card. An SD system is more complex than a conventional film/lightbox (the hard copy) display system, and it has many varieties. In radiology, the increasing number of picture archiving and communication system (PACS) implementations worldwide has led to an increasing number of diagnostic decisions being made based on images that are displayed on computer monitors. However, the quality of SD systems varies and there is no common, easy-to-use quality index to determine and to compare the quality of a display or to predict a user's performance. Furthermore, image processing and manipulation may partially compensate for an SD system's contrast and spatial resolution deficiency. 7,16,17 For instance, zooming in on an image on an SD work station can compensate for the spatial resolution limitations of the monitor. Also, it is possible to adjust image contrast by ''windowing and leveling'' of an image. However, these adjustments decrease a user's performance efficiency. Thus, it is important to ensure the optimization of the entire SD system so that unnecessary adjustments are minimized.

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confidence: 99%

Proposal of a Quality-Index or Metric for Soft Copy Display Systems: Contrast Sensitivity Study

Wang

Compton²,

Peng

2003

J Digit Imaging

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“…CRT displays however are prone to 'veiling glare' from the glass front, which can also reduce image quality. 13 TFT displays tend to have a higher luminance (typically about 178 vs 118 cd/m 2 for CRT), 12 which may result in lower contrast-detection thresholds.…”

Section: Discussionmentioning

confidence: 99%

Effect of video display on the grading of diabetic retinopathy

Costen

Newsom

Parkin

et al. 2004

Eye

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Purpose Digital images are increasingly being used in ophthalmology. These may be viewed either on thin-film transistor (TFT) or on cathode-ray tube (CRT) displays. However, there is little data showing which is superior. In this study, we compared the performance of CRT and TFT displays for grading of both compressed and uncompressed images of diabetic retinopathy. Methods A total of 49 35 mm transparencies of diabetic retinopathy were scanned and compressed. The images comprised 17 with no retinopathy, eight with background, five with preproliferative, and 19 with proliferative retinopathy. Four levels of compression were used: 0, 70, 80, and 90%. A total of 196 randomised images were presented to two masked graders using both TFT and CRT displays under uniform lighting conditions, 2 months apart. The grade of retinopathy was assessed. Statistical analysis of grading accuracy was performed using receiver operator characteristic curves of sensitivity and specificity and the Stuart-Maxwell test for paired, nonparametric data. Results Both displays showed high sensitivity and specificity for the detection of any retinopathy. For the specific grade of retinopathy, the CRT performed slightly better with a sensitivity of 0.80 for uncompressed images, compared with 0.75 using the TFT. Compression reduced these sensitivities to 0.73 on the CRT and 0.63 on the TFT. Grading of uncompressed images magnified to four times their original size was more accurate on the TFT. Conclusions Grading on both displays met sensitivity and specificity criteria proposed by Diabetes UK (formerly British Diabetic Association) for screening of diabetic retinopathy. The CRT generally performed slightly better than the TFT in relation to the detection of the specific grade of retinopathy.

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“…Consider some examples. For the purpose of medical diagnosis in radiology, where image quality is tied to the user's ability to detect subtle targets, Roehrig et al, (1990) consider the most essential parameters, FOMs, for describing CRT display quality to be spatial resolution, noise, characteristic curve, and absolute luminance, with the additional parameters of brightness uniformity, veiling glare and distortion also being important. For the purpose of computer graphics, where subjective aesthetic quality and realism are of paramount importance, Oakley (1984) states that the image quality of CRTs is most usefully described by the parameters of size, resolution, contrast ratio, geometric distortion, flicker, video bandwidth, and shades of gray (and chromaticity and convergence for color displays).…”

Section: Task 4 -Page 65mentioning

confidence: 99%

Contributive Research in Aviation Medicine, Bioengineering, Human Performance Analytic and Modeling Systems

Harding¹

2002

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Performance tests and quality control of cathode ray tube displays

Cited by 38 publications

References 9 publications

Proposal of a Quality-Index or Metric for Soft Copy Display Systems: Contrast Sensitivity Study

Proposal of a Quality-Index or Metric for Soft Copy Display Systems: Contrast Sensitivity Study

Effect of video display on the grading of diabetic retinopathy

Contributive Research in Aviation Medicine, Bioengineering, Human Performance Analytic and Modeling Systems

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