Patent ID: 7471415

Claim:
A system for a server to determine a plurality of lattice points to be referenced to prepare correspondence defining data that defines correspondence between an amount of ink for each color used by a printing apparatus connected to a client and a value of a color component in a specific color system, in which: said client has a unit to record original correspondence defining data which previously prescribes correspondence between the lattice points in a low-dimensional color space prescribed by less color components than a number of inks for each color and the lattice points for an ink amount in an ink amount space, a client's communication unit to transmit and receive data through a two-way communication line, and a unit to transmit the original correspondence defining data to the server through the client's communication unit; and said server has a server's communication unit to transmit and receive data through a two-way communication line, a unit to receive the original correspondence defining data through the server's communication unit, a unit to acquire correspondence between lattice points in the low-dimensional color space and lattice points in a device-independent color space by referencing the original correspondence defining data, a unit to prescribe a smoothness evaluation function which evaluates smoothness of an arrangement of lattice points in the device-independent color space and has as a variable information about a position of lattice points in the low-dimensional color space, the smoothness evaluation function having a minimum value when a first distance between a lattice point to be optimized and an adjacent lattice point in a first direction is equal to a second distance between the lattice point to be optimized and an adjacent lattice point in a second direction that is opposite to the first direction, and the smoothness evaluation function increasing in value as a difference between the first distance and the second distance increases, a unit to optimize the arrangement of lattice points in the device-independent color-space by improving a rating of the smoothness evaluation function, with the information about the position of lattice points varied, and a unit to determine lattice points for the correspondence defining data by associating the amount of ink for each color corresponding to lattice points in the low-dimensional color space specified by the information about the position of lattice points in an optimized state with lattice points in the low-dimensional color space prescribed by the original correspondence defining data.