1. An image processing apparatus that generates drawing data based on a drawing command, the drawing command including a background setting command that sets a background of the drawing data, the image processing apparatus comprising: a feature determining unit that determines a feature of a background for each line in the drawing command; and a background drawing unit that selects for each line a drawing method enabling a high-speed drawing process depending on the feature of that line, and draws drawing data corresponding to the background based on the background setting command and selected drawing method, wherein when performing rotation drawing processing, the feature determining unit determines the feature after the rotation drawing processing, with respect to a feature determining direction before the rotation drawing processing.