37,124 research outputs found
The impact of specialty settings on the perceived quality of medical ultrasound video
Health care professionals are increasingly viewing medical images and videos in a variety of environments. The perception of medical visual information across all specialties, career stages, and practice settings are critical to patient care and patient safety. Visual signal distortions, such as various types of noise and artifacts arising in medical imaging, affect the perceptual quality of visual content and potentially impact diagnoses. To optimize clinical practice, it is of fundamental importance to understand the way medical experts perceive visual quality. Psychophysical studies have been undertaken to evaluate the impact of visual distortions on the perceived quality of medical images and videos. However, very little research has been conducted on how speciality settings affect the perception of visual quality. In this paper, we investigate whether and how radiologists and sonographers differently perceive the quality of compressed ultrasound videos, via a dedicated subjective experiment. The findings can be used to develop useful solutions for improved visual experience and better image-based diagnoses
The impact of specialty settings on the perceived quality of medical ultrasound video
Health care professionals are increasingly viewing medical images and videos in a variety of environments. The perception of medical visual information across all specialties, career stages, and practice settings are critical to patient care and patient safety. Visual signal distortions, such as various types of noise and artifacts arising in medical imaging, affect the perceptual quality of visual content and potentially impact diagnoses. To optimize clinical practice, it is of fundamental importance to understand the way medical experts perceive visual quality. Psychophysical studies have been undertaken to evaluate the impact of visual distortions on the perceived quality of medical images and videos. However, very little research has been conducted on how speciality settings affect the perception of visual quality. In this paper, we investigate whether and how radiologists and sonographers differently perceive the quality of compressed ultrasound videos, via a dedicated subjective experiment. The findings can be used to develop useful solutions for improved visual experience and better image-based diagnoses
Fully-automatic inverse tone mapping algorithm based on dynamic mid-level tone mapping
High Dynamic Range (HDR) displays can show images with higher color contrast levels and peak luminosities than the common Low Dynamic Range (LDR) displays. However, most existing video content is recorded and/or graded in LDR format. To show LDR content on HDR displays, it needs to be up-scaled using a so-called inverse tone mapping algorithm. Several techniques for inverse tone mapping have been proposed in the last years, going from simple approaches based on global and local operators to more advanced algorithms such as neural networks. Some of the drawbacks of existing techniques for inverse tone mapping are the need for human intervention, the high computation time for more advanced algorithms, limited low peak brightness, and the lack of the preservation of the artistic intentions. In this paper, we propose a fully-automatic inverse tone mapping operator based on mid-level mapping capable of real-time video processing. Our proposed algorithm allows expanding LDR images into HDR images with peak brightness over 1000 nits, preserving the artistic intentions inherent to the HDR domain. We assessed our results using the full-reference objective quality metrics HDR-VDP-2.2 and DRIM, and carrying out a subjective pair-wise comparison experiment. We compared our results with those obtained with the most recent methods found in the literature. Experimental results demonstrate that our proposed method outperforms the current state-of-the-art of simple inverse tone mapping methods and its performance is similar to other more complex and time-consuming advanced techniques
Study of video quality assessment for telesurgery
elemedicine provides a transformative practice for access to and delivery of timely and high quality healthcare in resource-poor settings. In a typical scenario of telesurgery, surgical tasks are performed with one surgeon situated at the patient’s side and one expert surgeon from a remote site. In order to make telesurgery practice realistic and secure, reliable transmission of medical videos over large distances is essential. However, telesurgery videos that are communicated remotely in real time are vulnerable to distortions in signals due to data compression and transmission. Depending on the system and its applications, visual content received by the surgeons differs in perceived quality, which may incur implications for the performance of telesurgery tasks. To rigorously study the assessment of the quality of telesurgery videos, we performed both qualitative and quantitative research, consisting of semi-structured interviews and video quality scoring with human subjects. Statistical analyses are conducted and results show that compression artifacts and transmission errors significantly affect the perceived quality; and the effects tend to depend on the specific surgical procedure, visual content, frame rate, and the degree of distortion. The findings of the study are readily applicable to improving telesurgery systems
Stereoscopic Medical Data Video Quality Issues
Stereoscopic medical videos are recorded, e.g., in stereo endoscopy or during video recording medical/dental operations. This paper examines quality issues in the recorded stereoscopic medical videos, as insufficient quality may induce visual fatigue to doctors. No attention has been paid to stereo quality and ensuing fatigue issues in the scientific literature so far. Two of the most commonly encountered quality issues in stereoscopic data, namely stereoscopic window violations and bent windows, were searched for in stereo endoscopic medical videos. Furthermore, an additional stereo quality issue encountered in dental operation videos, namely excessive disparity, was detected and fixed. The conducted experiments prove the existence of such quality issues in stereoscopic medical data and highlight the need for their detection and correction
Applying psychological science to the CCTV review process: a review of cognitive and ergonomic literature
As CCTV cameras are used more and more often to increase security in communities, police are spending a larger proportion of their resources, including time, in processing CCTV images when investigating crimes that have occurred (Levesley & Martin, 2005; Nichols, 2001). As with all tasks, there are ways to approach this task that will facilitate performance and other approaches that will degrade performance, either by increasing errors or by unnecessarily prolonging the process. A clearer understanding of psychological factors influencing the effectiveness of footage review will facilitate future training in best practice with respect to the review of CCTV footage. The goal of this report is to provide such understanding by reviewing research on footage review, research on related tasks that require similar skills, and experimental laboratory research about the cognitive skills underpinning the task. The report is organised to address five challenges to effectiveness of CCTV review: the effects of the degraded nature of CCTV footage, distractions and interrupts, the length of the task, inappropriate mindset, and variability in people’s abilities and experience. Recommendations for optimising CCTV footage review include (1) doing a cognitive task analysis to increase understanding of the ways in which performance might be limited, (2) exploiting technology advances to maximise the perceptual quality of the footage (3) training people to improve the flexibility of their mindset as they perceive and interpret the images seen, (4) monitoring performance either on an ongoing basis, by using psychophysiological measures of alertness, or periodically, by testing screeners’ ability to find evidence in footage developed for such testing, and (5) evaluating the relevance of possible selection tests to screen effective from ineffective screener
Routine tests for both planning and evaluating image quality in tele-echocardiography
Both in real-time and "store & forward" tele-echocardiography (T-E), a coding process has to be applied to the echocardiography videoclips in order to limit the bandwidth needed and adapt it to the bandwidths furnished by network providers. The compression process degrades the videoclips, affecting thus the quality of the videoclips and potentially compromising the diagnostic accuracy of the T-E. In this work the authors investigated on the use of automatic tools for the video quality assessment by means of objective methods with particular care to the role of the system administrator. As the use of tests on video quality assessment (based on subjective methods) is hampered by the high number of needed resources (persons, laboratories and time). The use of valid objective methods is thus desirable. The study reviewed different tools with this specific aim. One of the more suitable tool was found to be represented by a software package designed by the Institute of Telecommunication Sciences and the National Telecommunication and Information Administration, the NTIA/ITS VQM tool. This tool gives back objective-quantitative data as outcomes, however embeds models emulating the subjective perception. This study reviewed and analyzed in depth the functionalities of the tool to improve the image quality in TE over the network. The tool was also found suitable for a more general process of T-E assessment, from a health technology assessment (HTA) perspective
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