人们经常把不稳定声信号的一些接续的短时间谱估计量以强度调制的频率—时间图(声谱图)的形式显示出来。本文研究了把某种形式的声谱图作为数字式图象来存储和处理中的某些问题及其优点。文中所讨论的特定形式的声谱图是由一根主要的基线和几根弱得多的谐频或准谐频线所组成的时变“线谱”的声源发出来的。这种类型的谱图通常由旋转机械产生。假定测得的这种信号混有加性宽带噪声。所得的声谱图由一族相互关联的线所组成,其中较 Often, some successive short-term spectral estimators of an unstable acoustic signal are displayed as an intensity-modulated frequency-time plot (spectrogram). This paper studies some of the problems and advantages of storing or manipulating some form of spectrogram as a digital image. The particular form of spectrogram discussed in this article is emitted from a time-varying “line spectrum” source consisting of a major baseline and several much weaker harmonic or quasi-harmonic lines. This type of spectrum is usually produced by a rotating machine. Assume that the measured signal is mixed with additive wideband noise. The resulting spectrogram consists of a family of interrelated lines, of which more