According to an aspect of the invention, an image processing apparatus includes a generating unit, a calculating unit, a receiving unit, and a changing unit. The generating unit generates a plurality of histograms of images with respect to each color based on an input image. The calculating unit calculates a plurality of first image densities of the images from the histograms. The receiving unit receives a content of image quality adjustment performed on the input image. The changing unit changes one of the histograms based on the content of the image quality adjustment. The one of the histogram corresponds to one of the images on which the image quality adjustment is performed. The calculating unit calculates a second image density corresponding to the one the images based on the one of the histogram changed by the changing unit.