Quality Metric Based Colour Palette Optimisation

Colour quantisation is a common image processing technique where full colour images are to be displayed using a limited palette. The choice of a good palette is therefore crucial as it directly determines the quality of the resulting image. Standard quantisation approaches typically try to minimise the (squared) error between the original and the quantised image which does not correspond well to how humans perceive the images. In this paper we introduce a new colour quantisation algorithm that is designed not to minimise these errors but to maximise the image quality as evaluated by S-CIELAB, an image quality metric that has been shown to work well for various image processing tasks. Experimental results based on a set of standard images demonstrate the superiority in terms of achieved image quality of our novel method.