A filter circuit includes: an adder/subtractor that performs at least addition; and a shifter that performs multiplication/division by a power of two through a shift operation. The adder/subtractors and the shifter are configured to obtain a first calculation result representing a pixel value of a target pixel included in image data multiplied by a first filter coefficient. At least the adder/subtractors and the shifter is configured to obtain a second calculation result representing pixel values of a plurality of peripheral pixels adjacent to the target pixel, with each of the pixel values being multiplied by a second filter coefficient. The adder/subtractor is configured obtain a third calculation result by adding the first and second calculation results. The shifter configured to divide the third calculation result by a power of two which is equivalent to a sum of the first and second filter coefficients, so as to output the division result. According to this aspect of the present invention, adders and subtractors, which have a lower cost and lower energy consumption than multipliers and dividers, are used along with shifters. It is therefore possible to realize the smoothing of images at low cost and low energy consumption.