The present invention provides an image processing device, an image processing method and an apparatus so as to improve at least the precision of extracting document corners in image processing performed on an image captured for a document. The image processing device includes: an extracting unit for extracting boundaries of a document in a first direction and roughly-detected document corners, where the first direction is a horizontal direction or a vertical direction of the document image; a determining unit for determining candidate page corners on the boundaries in the first direction around the roughly-detected document corners; and a selecting unit for determining document corners of the document among the candidate page corners. With the foregoing technology of the invention, more precise document corners can be extracted, a better effect of image processing can be obtained, and applications in the field of image processing are possible.