A new method of encoding and displaying audio Doppler-shift signals: the chromagram

A technique based on chromaticity is described for processing and displaying audio Doppler-shift signals. A chromaticity vector is derived for a fixed time interval (e.g. 5 ms) of the input Doppler signal, which is directly related to the Fourier power spectrum distribution of that signal over that interval. An approximated approach is then described for implementing the above "chromagraphic analysis" in order to meet Doppler ultrasound real-time requirements. A static and dynamic chromagram display format is defined which enables the chromaticity information to be displayed in colour on a digital television monitor.