In CCD based imaging systems operating in multiple output taps (channels), electronic channel crosstalk is a major issue that limits the image quality. We propose characterisation of crosstalk in a high speed image acquisition system that employs multi-tap CCD as the imaging sensor. The characterisation is performed by analysing imaged test patterns in frame mode. These test patterns are formed based on the analog signal flow architecture of the sensor and image acquisition system. Test patterns imaged from a high resolution monochrome monitor are analysed to observe and quantify crosstalk on every channel. This pattern image based approach formulated in a hierarchical manner can be applied to characterise crosstalk for any multi-port, multiplane sensor configuration of high speed imaging systems. © 2008 IEEE.