Motion blur results when a moving edge travels across a display, such as a liquid crystal display (LCD), that has limited temporal response. It is important to be able to quantify this effect in visual terms. The techniques described in this work provide methods for estimating the strength of the motion blur artifact in perceptual units of JNDs (just noticeable differences).
A main perceptual metric for motion blur is called visible motion blur (VMB). It incorporates three effects — contrast, masking, and visual resolution — and is based upon the Spatial Standard Observer to estimate visibility. VMB converts a moving edge temporal profile (METP), a discrete sequence of relative luminances, into a measure of motion blur quantified in the JND units. This is a standard perceptual measure in which one JND is the least quantity that can be seen with specified reliability. The metric correctly reflects the effect of edge contrast on the visibility of the blur artifact. Furthermore, the metric takes into account all departures of the image from a perfect edge, including blur, overshoot, undershoot, and ringing.
This technique has been developed to address the lack of commercial tools and standards that measure motion blur. There are several standards for measuring data quality and voice quality over analog and digital networks, but there is no current standard measure of display motion blur, which is a significant defect in most current display technologies.
Motion blur arises when the display presents individual frames that persist for significant fractions of frame duration. When the eye smoothly tracks a moving image, the image is smeared across the retina during frame duration. Although motion blur may be manifest in any moving image, one widely used test pattern is called moving-edge blur.
VMB technology establishes a standard method of objectively measuring motion blur. It improves the accuracy and precision of motion picture response time (MPRT) measurements, but does not require any pursuit cameras, and can be administered by novice users and measurement personnel. It also introduces measures of sensitivity to blur in moving edges and converts MPRT data into perceptual units. It provides methods for estimating the strength of the motion blur artifact in perceptual units of JND. This technology automates part of the process of flat-panel display inspection, which still relies on human inspectors, and thereby brings consistency and reliability.