The image forming apparatus includes: a first group of large nozzles which eject large droplets of liquid for a color; a second group of small nozzles which eject small droplets of the liquid for the color, the small droplets having volume smaller than the large droplets; a dot data creation device which creates dot data according to input image data; a dot data correction device which corrects the dot data if there is an abnormal nozzle in one of the first and second groups, in such a manner that a corrective nozzle is selected from the other of the first and second groups, and droplet ejection performed by the corrective nozzle substitutes for droplet ejection that is originally to be performed by the abnormal nozzle; and a driving device which drives the large and small nozzles to eject the large and small droplets according to the corrected dot data.