An image forming apparatus and method includes a controller to set a reference fusing temperature according to the print pattern of an input image received from an image input unit. The input image is converted to bitmap data to recognize the print pattern. The reference fusing temperature is set higher as the transition rate of the converted bitmap data increases. When printing an image whose print pattern has a low transition rate, the apparatus reduces the time required to print the first page of the image, thereby improving the print speed over the conventional apparatus.