Accelerating spectral-based color separation within the Neugebauer subspace

bstract. Spectral separation is the process of obtaining printer ontrol values to reproduce a given spectral reflectance. Given a ultispectral image where each pixel represents a spectral reflecance, separation could be implemented by inverting a physical rinter model on a pixel-by-pixel basis. Such a process would obviusly need to be very fast to handle high-resolution images in a easonable time. For a printer whose spectral response is characerized by the Yule–Nielsen spectral Neugebauer model, the linear egression iteration (LRI) method can be used to invert the model. e introduce the subspace linear regression iteration (SLRI) ethod, a modification of LRI shown to be significantly accelerated ue to performing its calculations within the subspace determined y the Neugebauer primaries. Using this subspace approach, the umber of multiplications becomes independent of the spectral samling rate. Using a standard six color printer and a common spectral ampling rate, the number of multiplications can be decreased by bout two-thirds without changing the convergence behavior. 2007 SPIE and IS&T. DOI: 10.1117/1.2805447