1. A method for use with a digital image processing system for transforming a digital signal represented by a set of values from a first four dimensional device-dependent color space to a digital signal represented by a set of values in another four dimensional device-dependent color space comprising the steps of: (a) providing one of a plurality of corresponding four dimensional first device-dependent color space values and one of a plurality of corresponding four dimensional second device-dependent color space values; (b) converting the one of the four dimensional first device-dependent color space values and the one of the four dimensional second device-dependent color space values to a corresponding converted three dimensional first device-independent color space value and converted three dimensional second device-independent color space values; (c) determining a first error value from the converted three dimensional first device-independent color space value and the converted three dimensional second device-independent color space value; (d) determining a second error value from the one of the four dimensional second device-dependent color space values and one of the four dimensional first device-dependent color space values; (e) determining an error metric value from the first error value and the second error value; and (f) comparing the error metric value with a threshold value and providing the one of a plurality of corresponding four dimensional second device-dependent color space values as an output value when the error metric value is less than the threshold value.