Patent ID: 8089657

Claim:
A calibration device comprising: an output value measuring unit that measures an output value of an image representing a present input/output characteristic; a relative-value correction unit that performs a normalization for the measured output value based on a possible range of the measured output value and a normalization for a design target output value corresponding to the measured output value based on a range of the design target output value; an absolute-value correction unit that performs a normalization for the measured output value and the design target output value based on the range of the design target output value; a relative-value calibration unit that calibrates the measured output value normalized by the relative-value correction unit with reference to a characteristic of the design target output value normalized by the relative-value correction unit; an absolute-value calibration unit that calibrates the measured output value normalized by the absolute-value correction unit with reference to the design target output value normalized by the absolute-value correction unit; and a hybrid calibration unit that causes the relative-value calibration unit and the absolute-value calibration unit to operate according to a predetermined ratio, wherein: the input/output characteristic is a density/gray level characteristic including an input value corresponding to a gray level, and the output value is a density value corresponding to the input value; and the relative-value correction unit performs the normalizations by: obtaining a normalized density value DRi′ corresponding to a design target density value DRi according to: DRi ′=(( DRi−DR min)/( DR max− DR min))× N where N is a maximum input value, DRmin is a minimum design target density value, DRmax is a maximum design target density value, and i=0, 1, 2, . . . , N−1, N; and obtaining a normalized density value DCi′ corresponding to a measured density value DCi according to: DCi ′=(( DCi−DC min)/( DC max− DC min))× N where DCmin is a minimum measured density value, and DCmax is a maximum measured density value.