Medical Image Quality Assessment for Stereoscopic Display Devices Using Computational Observers
Creators: name: Zafar, Fahad
Publisher: name: Maryland Shared Open Access Repository
Year: 2014
Subjects: 3D
computational models
crosstalk
stereo

description: As stereoscopic display devices become common, their image quality evaluation becomes increasingly important. Most studies conducted on 3D displays rely on measurements recorded through instruments or on preference experiments with humans rating their visual experience when viewing 3D content. Currently, there is no evident link that correlates physical measurements with effects on signal detection performance or perceptual issues concerning medical imaging applications. Additionally, existing human observer study results are often subjective and difficult to generalize. We designed a computational stereoscopic observer approach inspired by the mechanisms of stereopsis in human vision for task-based image quality assessment based on a set of image pairs. The stereo-observer is constrained to a left and a right image generated using a visualization operator to render 3D datasets. We analyze white noise and lumpy backgrounds using volume rendering techniques. Our simulation framework generalizes many different types of model observers including existing 2D and 3D observers as well as providing flexibility to formulate a stereo model observer approach following the principles of stereoscopic viewing. We show results quantifying the changes in performance when varying stereo angle as measured by an ideal linear stereoscopic observer. Our findings indicate that there is an increase in performance of about 13-18$%$ for white noise and 20-46% for lumpy backgrounds, where the stereo angle is varied from 0 to 30 degrees. Additionally, different stereo devices have different performance trade-offs due to their display characteristics. Among them, crosstalk is known to affect observer perception of 3D content. We measured and report the luminance output and crosstalk characteristics for three different technologies of stereoscopic display devices. We recorded the effect of other issues on luminance profiles such as viewing angle, use of different eye wear, and screen location. Our results show that the crosstalk signature for viewing 3D content can vary considerably when using different types of 3D glasses for active stereo displays. We also show that significant differences are present in crosstalk signatures when varying the viewing angle from 0 to 20 degrees for a stereo mirror 3D display device. Combining our stereoscopic observer model and the luminance data recorded for three types of stereoscopic display devices, we quantify the effect of crosstalk on signal detection performance when using these devices linking physical device luminance data to computational trials. We found that newer version of glasses for the active stereo display device had 30% higher signal detection performance compared to the older one due to the difference in crosstalk attributed to these peripherals. As crosstalk is reduced when viewing a passive 3D display screen at varying angles, the performance of the observer increased. There was no change in performance when different screen location crosstalk data was used for assessment using the crosstalk stereo model observer. Our methodology can be extended to emulate other parameters by modifying the display model. The applicability of our observer framework extends to stereoscopic displays used for in the areas of medical, entertainment, and other demanding imaging applications.