| 摘要 |
The digitisation and storage of the information contained in a video frame at the rate of the system clock has the following problems: Random access to the memory content and simple postprocessing are not possible due to the predetermined clock times; in particular, overwriting of freely selected data in the memory has not been possible with previous systems. The solution is obtained by dividing the memory into four subdivisions which operate in parallel by advantageously selecting addressing, in such a manner that in each case one subdivision is ready for reading/writing the data present. Due to this preaddressing, the entire memory area can be considered from the outside as if its read/write cycle were four times shorter than that of its individual chips. This makes it possible to digitise the image supplied by a CCD camera at a clock rate of 7 MHz and to store it in a 256-kByte memory formed from 4116-type RAMs. An interface provides for the reading-out, writing and controlling of the sequence by means of any computer. If the computer does not address the system, the memory content is periodically output for generating a still image on a monitor. The system can be used for recording intensity profiles in two dimensions, storing and processing images which do not last less than one frame period of a complete video frame.
|
