| 摘要 |
<p>A method of and an apparatus for generating a visual record that extends over a period of time. Data signals are transmitted to a control unit (1), the signals including picture signals from a camera (2) and signals from one or more types of sensing devices (4A, 4B, 4C). A record of only some of the picture signals is maintained. The degree of difference of at least one type of the transmitted data signals from data signals of the same type that have previously been recorded is assessed and only when the degree of difference assessed is greater than a preselected threshold amount is a record of the picture signals maintained.</p> |
