An inkjet image forming apparatus and a method to control the same to correct characteristics of a plurality of print heads of the apparatus to have uniform characteristics includes a plurality of test patterns printed according to the timing of printing of dots through a row of odd nozzles and a row of even nozzles of each of the plurality of print heads and information of the drive timing corresponding to a brightest test pattern of the printed test patterns is stored. When a normal print operation is performed, a different drive timing is applied to each of the plurality of print heads based on the stored information, thereby compensating for the difference between the one or more characteristics of the print heads.