Abstract: An adaptive flash rejection filter for a color flow imaging apparatus uses a flash strength identifier to make an initial determination of flash content. The identifier assigns a flash strength to each signal portion of a scan line according to a velocity component and a magnitude component of that signal portion. The number of flash strengths in a line which fall into a designated flash range are accumulated to arrive at an approximate measure of flash content. A filter arrangement uses the accumulated flash content to determine a proper flash rejection level for a line. An entire line of flash strengths and velocity measurements are stored in a line memory, which serves to delay those signals while the proper flash rejection level is being determined. The filter arrangement then receives the flash strengths and the velocity components, and inhibits an output of a velocity component if its corresponding flash strength exceeds the assigned flash rejection level.