Factors affecting development of a motion imagery quality metric

Abstract

The motion imagery community would benefit from the availability of standard measures for assessing image interpretability. The National Imagery Interpretability Rating Scale (NIIRS) has served as a community standard for still imagery, but no comparable scale exists for motion imagery. Several considerations unique to motion imagery indicate that the standard methodology employed in the past for NIIRS development may not be applicable or, at a minimum, require modifications. Traditional methods for NIIRS development rely on a close linkage between perceived image quality, as captured by specific image interpretation tasks, and the sensor parameters associated with image acquisition. The dynamic nature of motion imagery suggests that this type of linkage may not exist or may be modulated by other factors. An initial study was conducted to understand the effects target motion, camera motion, and scene complexity have on perceived image interpretability for motion imagery. This paper summarizes the findings from this evaluation. In addition, several issues emerged that require further investigation:The effect of frame rate on the perceived interpretability of motion imagery Interactions between color and target motion which could affect perceived interpretability The relationships among resolution, viewing geometry, and image interpretability The ability of an analyst to satisfy specific image exploitation tasks relative to different types of motion imagery clips Plans are being developed to address each of these issues through direct evaluations. This paper discusses each of these concerns, presents the plans for evaluations, and explores the implications for development of a motion imagery quality metric.

Application of VNIIRS for target tracking

“…Initial derivations were done by Irvine et al [48,49,50,51] to lay a foundation for a motion imagery quality metric that utilized the NIIRS ground sampling distance. They looked at the varying frame rate [52], perceived interpretability [53], and eventually the interpretability scale [54].…”

Quantifying Interpretability Loss due to Image Compression

“… Task Performance: The evaluations assessed the ability of imagery analysts to perform various image exploitation tasks with motion imagery. The tasks included detection and recognition of objects, as might be done with still imagery and the detection and recognition of activities, which relies on the dynamic nature of motion imagery (Irvine et al 2006b;Irvine et al 2007c). Analysts exhibited good consistency in the performance of these tasks.…”

“…The work presented in this paper quantifies video interpretability using a 100-point scale described in Section 3 (Irvine et al 2007a;Irvine et al 2007b;Irvine et al 2007c). The scale development methodologies imply that each scale is a linear transform of the other, although this relationship has not been validated (Irvine et al 2006a;Irvine et al 2006b). Other methods for measuring video image quality frequently focus on objective functions of the imagery data, rather than perception of the potential utility of the imagery to support specific types of analysis Watson and Kreslake 2001;Winkler 2001;Winkler et al 2001).…”

“… Spatial resolution: Evaluations shows that for motion imagery the interpretability of an video clip exhibits a linear relationship with the natural log of the ground sample distance (GSD), at least for clips where the GSD is fairly constant over the clip (Cermak et al 2011;Irvine et al 2004;Irvine et al 2005;Irvine et al 2007b) .  Motion and Complexity: User perception evaluations assessed the effects of target motion, camera motion, and scene complexity on perceived image quality (Irvine et al 2006b).…”

“… Motion and Complexity: User perception evaluations assessed the effects of target motion, camera motion, and scene complexity on perceived image quality (Irvine et al 2006b). The evaluations indicated that target motion has a significant positive effect on perceived image quality, whereas camera motion has a barely discernable effect.…”