1. An image processing apparatus comprising: a gain calculation unit that calculates a plurality of first gains that respectively correspond to a plurality of predetermined edges based on a target pixel value and values of pixels adjacent to the target pixel; a blend ratio calculation unit that calculates a plurality of characteristic amounts that represent an accuracy of detecting the plurality of edges based on the target pixel value and the values of pixels adjacent to the target pixel and calculates a plurality of weights that respectively correspond to the plurality of first gains based on the plurality of characteristic amounts; a gain adjustment unit that calculates a second gain based on the plurality of first gains and the plurality of weights; and an output image generation unit that applies the second gain to the target pixel value to generate output image data.