<title>Simplified method for video performance evaluation</title>

Abstract

Meaningful performance evaluation of video equipment can be complex, requiring specialized equipment in which results must be interpreted by technically trained operators. The alternative to this has been to attempt evaluation by visual inspection of patterns such as the SMPTE RP-133 Medical Imaging Standard. However this involves subjective interpretation and does not indicate the point in a system at which degradation has occurred. The video waveform of such a pattern is complex and not suitable for quantitative analysis.The principal factors which influence quality of a video image on a day-to-day basis are resolution, gray scale and color, if employed. If these qualities are transmitted arid displayed without degradation beyond acceptable limits, suitable performance is assured.Performance evaluation by inspection of the image produced on a video display monitor is subject to interpretation; this is resolved by inserting, at the display, the original "perfect" electronically generated waveform to serve as a reference. Thus the viewer has a specific visual comparison as the basis for performance evaluation.Another valuable feature of the test pattern insert is that a test segment can be placed on recorded images. Thus each image recalled by tape playback or from digital storage will carry an integral means for quality assurance.