Calibration of imaging system to compensate for variations in camera and local lighting

摘要

The calibration of an imaging system having a camera 20 for capturing colour data for a target object such as carcass 10 includes a primary calibration to obtain a primary transform for RGB data to enable compensation for variations in camera operation or characteristics. There is also a secondary calibration to obtain a secondary transform to enable compensation for local lighting conditions during capture and processing of colour data for captured images to be analysed. The calculated primary transform relates the actual measured colour data to known standard colour data for colour standard specimens. The standard colour specimens are presented in an enclosure or hood to the camera under controlled illumination and with extraneous or external light being excluded from illuminating the specimens. A preliminary calibration includes calibrating the primary calibration standard colour specimens and associated controlled light source against centralised laboratory standard colours.