Signal correction device, image reading device, image processing apparatus, signal correction method, and computer program product

A signal correction device includes a correction signal generator configured to generate a correction signal serving to remove noise superimposed on an input signal; a phase adjuster configured to shift a phase of the correction signal generated by the correction signal generator; a subtractor configured to generate an output signal for output by subtracting the correction signal from the input signal; a peak and bottom detector configured to detect a peak value and a bottom value of the output signal; and a determiner configured to determine a phase-shift amount of the phase adjuster from the peak value and the bottom value of the output signal detected by the peak and bottom detector. The determiner detects uncorrected noise from the peak value and the bottom value of the output signal from the subtractor, and sets the phase-shift amount such that the uncorrected noise is reduced to a minimum.