Tariq Bakir

Loss of Interpretability due to Compression Effects as Measured by the New Video NIIRS

The effect of video compression is examined using the task-based performance metrics of the new Video National Intelligence Interpretability Rating Scale (Video NIIRS). Video NIIRS is a subjective task criteria scale similar to the well-known Visible NIIRS used for still image quality measurement. However, each task in the Video NIIRS includes a dynamic component that requires video of sufficient spatial and temporal resolution. The loss of Video NIIRS due to compression is experimentally measured for select cases. The results show that an increase in the compression and an associated increase in artifacts reduces task based interpretability and lowers the Video-NIIRS rating of the video clips. The extent of the effect has implications for system design.

Factors Related to Low Slant Angle Affecting Airborne Video Interpretability

The following material is given to address the effect of low slant angle on video interpretability: 1) an equation for the minimum slant angle as a function of field-of-view to prevent no more than a &sqrt2; change in GSD across the scene; 2) evidence for reduced situational awareness due to errors in perceived depth at low slant angle converting to position errors; 3) an equation for optimum slant angle and target orientation with respect to maximizing exposed target area; 4) the impact of the increased probability of occlusion as a function of slant angle; 5) a derivation for the loss of resolution due to atmospheric turbulence and scattering. In addition, modifications to Video-NIIRS for low slant angle are suggested. The recommended modifications for low-slant angle Video-NIIRS are: 1) to rate at or near the center of the scene; and 2) include target orientations in the Video-NIIRS criteria.

Video National Imagery Interpretability Rating Scale criteria survey results

The Video National Imagery Interpretability Rating Standard (V-NIIRS) consists of a ranked set of subjective criteria to assist analysts in assigning an interpretability quality level to a motion imagery clip. The V-NIIRS rating standard is needed to support the tasking, retrieval, and exploitation of motion imagery. A criteria survey was conducted to yield individual pair-wise criteria rankings and scores. Statistical analysis shows good agreement with expectations across the 9-levels of interpretability, for each of the 7 content domains.

Non-Negative Maximum Likelihood ICA for Blind Source Separation of Images and Signals with Application to Hyperspectral Image Subpixel Demixing

The use of independent component analysis (ICA) methods for blind source separation of signals and images has been demonstrated in many applications and publications. While many ICA based algorithms for source separation exist, few impose physical constraints on the recovered independent components and the mixing matrix. Of particular interest is the non-negativity of the recovered independent components and the recovered mixing matrix. Such constraints are important for example when trying to do subpixel demixing on hyperspectral images. In this article, we propose a constrained non-negative maximum-likelihood ICA (CNML-ICA) algorithm that tackles the limitations of some existing non-negative ICA methods.

Video quality and interpretability study using SAMVIQ and Video-NIIRS

The effect of various video encoders, and compression settings is examined using the subjective task-based performance metric, Video National Imagery Interpretability Rating Scale (Video-NIIRS), and a perceptual quality metric Subjective Assessment Methodology of Video Image Quality (SAMVIQ). Subjective results are compared to objective measurements.

Cognitive modeling to predict video interpretability

Processing framework for cognitive modeling to predict video interpretability is discussed. Architecture consists of spatiotemporal video preprocessing, metric computation, metric normalization, pooling of like metric groups with masking adjustments, multinomial logistic pooling of Minkowski pooled groups of similar quality metrics, and estimation of confidence interval of final result.

Color in perceptual tracking using low frame rate motion imagery

A perceptual evaluation compared tracking performance when using color versus panchromatic synthetic imagery at low frame rates. Frame rate was found to have an effect on tracking performance for the panchromatic motion imagery. Color was found to be associated with improved tracking performance at 2 frames per second (FPS), but not at 6 FPS or greater. A self estimate of task confidence given by the respondents was found to be correlated to the measured tracking performance, which supports the use of task confidence as a proxy for task performance in the future development and validation of a motion imagery rating scale.

Task based video interpretability as a function of frame rate, playback rate, and target motion

The effect of low sample frame rate on interpretability is often confused with the impact it has on encoding processes. In this study, the confusion was avoided by ensuring that none of the low-frame rate clips had coding artifacts. Under these conditions, the lowered frame rate was not associated with a statistically significant change in interpretability. Airborne, high definition 720P, 60 FPS video clips were used as source material to produce test clips with varying sample frame rates, playback rates, and degrees of target motion. Frame rates ranged from 7.5 FPS to 60 FPS. Playback rates ranged up to 8X normal speed. Target motion ranged from near zero MPH up to 300 MPH.