Velocital information feature for charting spatio-temporal changes in digital image sequences

This paper introduces a velocital information feature that is extracted for each frame of an image sequence. The feature is based on the optical flow in each frame. A mathematical formulation for the velocital information feature is derived. Charting the feature over a sequence provides a quality metric called velocital information content (VIC). The relationship of VIC to the spatial and temporal information content is shown. VIC offers a different role from traditional transmission-based quality metrics which require two images: the original input image and degraded output image to calculate the quality metric. VIC can detect artifacts from a single image sequence by charting variations from the norm. Therefore, VIC offers a metric for judging the quality of the image frames prior to transmission, without a transmission system or without any knowledge of the higher quality image input. The differences between VIC and transmission-oriented quality metrics can provide a different role for VIC in analysis and image sequence processing. Results show that VIC is able to detect gradual and sudden changes in an image sequence. Results are shown for using VIC as a filter on electro-optical infrared image sequences where VIC detects frames suffering from erratic noise. © 1999 SPIE and IS&T. [S1017-9909(99)00302-5]