Embodiments of a processing systems and methods can unbend an image of facing pages of a bound book. An exemplary processing system can comprise an edge-detection unit, a keystone-correction unit, a flattening unit, and a conversion unit. After an image is received by the processing system, the image can be processed in turn by each unit. The edge-detection unit can identify edges of a document in the image. The keystone-correction unit can reduce or remove keystoning in the image, thereby correcting horizontal distortion of the document. The flattening unit can flatten or straighten text or objects in the image, thereby correcting vertical distortion of the document. The conversion unit can convert the image to a desired color profile. Accordingly, the processing system can process an original image into a more easily readable and digitally manipulable image.