一、电子档案我们不仅可以通过保存文件本身,通过保存文件的可读图象(如缩微胶片)来存储文件信息,也可通过保存代表文件的电子信号来存储文件信息。后一种情况,文件被扫描产生电子信号后,接着就被记录到磁带或光盘上。该信号可以是代表图象的模拟信号或数字记录。模拟信号是图象的不同亮度转换成相应的电压或频率。数字记录中,图象的每个象素亮度 First, the electronic file We can not only save the file itself, by saving the file readable image (such as microfilm) to store file information, but also by storing the electronic signal representing the file to store file information. In the latter case, the document is scanned to produce an electronic signal which is then recorded on a magnetic tape or optical disk. The signal can be an analog signal or digital record representing the image. Analog signals are the different brightness of the image converted to the corresponding voltage or frequency. In digital recording, the brightness of each pixel of the image