DATA CONVERSION DEVICE, DATA CONVERSION METHOD, AND RECORDING MEDIUM

1 . A data conversion device comprising:

a processor configured to:

acquire image data output from a first line sensor; and

convert pixel values included in the image data output from the first line sensor, in accordance with correspondence relation data in which a correspondence relation of pixel values is set based on a sensitivity difference for a spectral characteristic between the first line sensor and a second line sensor that is different from the first line sensor.

2 . The data conversion device according to claim 1 , wherein the correspondence relation data is set by histogram matching of two pieces of image data obtained when a same medium is read by the first line sensor and the second line sensor.

3 . The data conversion device according to claim 1 , the processor is further configured to:

multiply an inverse element gain to eliminate an influence of a transportation mechanism of a model for the first line sensor on an output of an imaging element of the first line sensor, by the pixel values included in the image data output from the first line sensor, and

convert the pixel values included in the image data after the inverse element gain is multiplied.

4 . The data conversion device according to claim 3 , wherein based on an output in a case where a medium with uniform reflection density and transmission density is read by the first line sensor, a coefficient at which the output of the imaging element of the first line sensor becomes a target value of the line sensor corresponding to a density of the medium is set for the inverse element gain.

5 . The data conversion device according to claim 1 , the processor is further configured to correct a degree of blurring of a watermark part of a banknote in the image data in which the pixel values are converted in accordance with a difference between a gap between a banknote transportation path and an imaging element of the first line sensor and a gap between a banknote transportation path and an imaging element of the second line sensor.

6 . The data conversion device according to claim 1 , the processor is further configured to multiply a transportation filter that adds an influence of a transportation mechanism of a model for the second line sensor on an output of an imaging element of the second line sensor, by the image data in which the pixel values are converted.

7 . The data conversion device according to claim 6 , wherein the transportation filter is set based on a difference between a density of a medium with uniform reflection density and transmission density and an output in a case where the medium is read by the second line sensor.

8 . A data conversion method comprising:

acquiring image data output from a first line sensor; and

converting pixel values included in the image data output from the first line sensor, in accordance with correspondence relation data in which a correspondence relation of pixel values is set based on a sensitivity difference for a spectral characteristic between the first line sensor and a second line sensor that is different from the first line sensor, by a processor.

9 . A non-transitory computer-readable recording medium storing therein a data conversion program that causes a computer to execute a process comprising:

acquiring image data output from a first line sensor; and

converting pixel values included in the image data output from the first line sensor, in accordance with correspondence relation data in which a correspondence relation of pixel values is set based on a sensitivity difference for a spectral characteristic between the first line sensor and a second line sensor that is different from the first line sensor.