THE INTERDISCIPLINARY CONTINUUM: RECONCILING THEORY, RESEARCH AND PRACTICE

Method and apparatus for transforming color signals in order to reproduce a tone on an original document faithfully, and an apparatus for executing the method. The color signals transforming method comprises the steps of dividing each of three input signals representative of colors into the higher bits and the lower bits, combining the higher bits to form basic data, combining the higher and lower bits to form interpolation data, and adding the basic data and the interpolation data to each other, thereby forming output signals, in which the hexahedron of an object to be interpolated is divided into six tetrahedrons each passing through one of eight lattice points constituting the hexahedron of the interpolated object, and the different combinations of interpolation data are assigned to the tetrahedrons in one-to-one correspondence manner.