An image modulation apparatus includes a device information obtaining unit to obtain device property information of a plurality of display devices respectively disposed at a plurality of image distribution destination apparatuses; a simulated image generator to generate a simulated image to be displayed on each of the display devices disposed at each of the image distribution destination apparatuses based on a distribution target image, to be transmitted to each of the image distribution destination apparatuses, and the device property information of each of the display devices obtained by the device information obtaining unit; and an image modulation unit to modulate the distribution target image based on a modulation instruction prepared for the plurality of the simulated images simulated by the simulated image generator.