(1) A type of distance metric showing the distance between two colours in the H*SP sinusoidal model. Unlike in the cylindrical model, the poles representing pure white and black are pinched into points. This metric corresponds to the human experience of colour better than the other hue-saturation metrics, in that the hue difference in very light and very dark values is suppressed. E.g. strong blue and strong red are shown as being farther apart from each other than very dark blue and very dark red.

(2) A type of distance metric showing the distance between two colours in the H*SP sinusoidal model. Unlike in the cylindrical model, the poles representing pure white and black are pinched into points. This metric corresponds to the human experience of colour better than the other hue-saturation metrics, in that the hue difference in very light and very dark values is suppressed. E.g. strong blue and strong red are shown as being farther apart from each other than very dark blue and very dark red.