Spectral characterization of COTS RGB cameras using a linear variable edge filter

The spectral response function of a camera maps the relative sensitivity of the camera imaging system as a function of the wavelength of the light. The spectral response function of the colour channels of a commercial-off-the-shelf (COTS) Red/Green/Blue (RGB) camera is often unknown and not typically provided by the manufacturer of the camera. Knowledge of this response can be useful for a wide variety of applications such as simulating animal vision, colour correction and colour space transformations of the images captured by the camera. COTS cameras are widely used due to their low cost and ease of implementation. We investigate a method of using a Linear Variable Edge Filter (LVEF) and a low-cost spectrometer to characterise an RGB camera. This method has the advantage over previous methods in the simplicity and small number of measurements needed for spectral characterisation. Results are presented for three cameras: a consumer-level digital SLR and two point-and-shoot consumer grade cameras, one of them being an underwater camera.