1. An image processing apparatus performing a compression process on an input image, the image processing apparatus comprising: background layer generation means generating a background layer by extracting a text region from the input image and removing at least the text region from the input image; background region extraction means extracting, from the background layer, a background region corresponding to a color characteristic, the background region extraction means including: background color estimation means estimating, from the background layer, a background color that is a uniform local background color determined to belong in a same color, according to the color characteristic, or a uniform page background color determined to belong in a same color, according to the color characteristic; and background image extraction means extracting, from the background layer, the background region having the background color estimated; coordinate recording section recording coordinate values of the background region extracted by the background region extraction means; and data storage section storing the background region in a form in accordance with the color characteristic of the background region extracted by the background region extraction means, the data storage section storing a local background and a page background as information including the background color estimated by the background color estimation means and the coordinate values of the background region having the background color, the local background and the page background being included in the background layer.