Controlling the error in spectral vector error diffusion

We aim to print spectral images using spectral vector error diffusion. Vector error diffusion produces good quality halftoned images but it is very slow to diffuse the error in the image during the halftoning process due to error accumulation. In spectral images each pixel is a re.ectance and the accumulation of error can modify completly the shape of the reflectance. This phenomena is increased when data are out of the gamut of the printer. To control the diffusion of error and to decrease the slowness of the spectral vector error diffusion we preprocess the spectral image by applying spectral gamut mapping and test the shape of the reflectances by keeping them in a range of feasible values. Our spectral gamut mapping is based on the inversion of the spectral Neugebauer printer model. After preprocessing the spectral image to be halftoned is the closest estimation the printer can made of it with the available colorants. We apply spectral vector error diffusion to spectral images and we evaluate the halftoning by simulation. We use a seven channels printer which we assume has stable inks and no dot gain (with a large set of inks we increase the variability or re.ectances the printer can produce). Our preprocessing and error control have shown promising results.