Research of TV system's view range evaluation based on human eyes' contrast threshold

摘要

Johnson criteria not only compartmentalizes photoelectronic imaging systems' detecting level, but also establishes a relation between imaging systems' detecting level of different target and equivalent stripes with 100% contrast. Base on this criteria we can calculate photoelectronic imaging systems' view range. Blackwell's classic experiments provide basic data of human eyes' contrast detecting. Base on this theory, we get restrict relation between human eyes' contrast threshold and human eyes' resolving power. Base on the two theory, this paper has thoroughly studied the imaging and display parts of TV systems. At the same time, TV systems' view range problem has been discussed in this paper using Johnson criteria and human eyes' contrast threshold curve, combined with the objects' size, the contrast between the objects and the backgrounds, the atmosphere's transfer characteristic, apparent contrast's change. This paper gives a method to calculate TV systems' view range under different detecting and recognizing probabilities. Base on this method and an actual TV system's characteristics, the paper has calculated the view range of representative objects under different detecting and recognizing probabilities.