Image photometry applied to measuring visual displays

The image photometer measures the photometric characteristics of part or all of a scene stored as photometrically valid image data obtained from a calibrated electronic camera. The technology can offer significant advantages over other photometric methods for measuring visual displays where: the information content in the display measurements is moderate to large. photometric readings must be obtained from irregularly shaped regions in the display and/or from many regions distributed throughout the display. repetitive photometric measurements must be taken on a succession of similar parts.. numerical analysis of the photometric data is required. timely decisions must be made based upon photometric analysis. summary documentation must be produced. archiving measured data, analyses and/or summary reports is required. photometric results must be compared to one or more standards. We review the characteristics of the components of the image photometer and its calibration and discuss how they affect the validity and reliability of its measurements. We also discuss how specific design features affect the robustness and ease of use of the display measurement process. The costs and benefits of image photometry are compared to the current alternative photometric measurement technologies.