In an image recording apparatus, reference patterns are provided on a surface of a transport belt that transports a recording medium such as paper attracted thereto to image recording sections defined by recording heads. It is arranged such that the reference patterns are detected while being transported as the transport belt is driven, and a speed change of the transport belt and a position shift in a direction perpendicular to the transporting direction of the transport belt are calculated based on information resulting from the detection, thereby controlling ejection timing and ejection position of ink droplets ejected from the recording heads.