Grey-wavelet: unifying grey-world and grey-edge colour constancy algorithms
In this paper, we propose the grey-wavelet hypothesis for colour constancy which assumes that both the average reflectance of surfaces and the average of reflectance differences in a scene are achromatic. The framework combines well-known grey-world and grey-edge hypotheses under the wavelet framework. The quality of the various instantiations of the framework is evaluated on set of images of colourful objects under a controlled indoor setting and on real-world datasets containing mainly outdoor scenes. The experiments show that the proposed colour constancy algorithm obtains better results than the state-of-the-art colour constancy algorithms of similar complexity. Since the framework operates in wavelet transform domain, it can be easily adopted to JPEG2000 for the purpose of colour constancy.
colour constancy discrete wavelet transform multiscale analysis photometric invariance