An image processing apparatus includes: a filter-coefficient storing unit that stores filter coefficients respectively associated with spatial frequencies, which are the numbers of strips displayed per unit angle with respect to an angle of field of a display apparatus; a viewing-condition determining unit that determines, as viewing conditions, a viewing distance between a viewer and the display apparatus and pixel density of the display apparatus; a filter-coefficient setting unit that sets a filter coefficient selected on the basis of a spatial frequency calculated from the viewing conditions among the stored filter coefficients; and a gradation modulating unit including a quantizing unit that quantizes a pixel value in a predetermined coordinate position in an image signal and outputs the pixel value as a quantized pixel value in the predetermined coordinate position, the gradation modulating unit gradation-modulating the image signal by multiply-accumulating a set filter coefficient with respect to quantization errors caused by the quantizing unit to feedback the quantization errors to an input side of the quantizing unit.