1. A method for area identification, comprising: identifying a plurality of candidate predefined edges in a document image of a document, the candidate predefined edges being edges in a predefined direction of the document; determining one of the candidate predefined edges to be a target predefined edge; and identifying at least one information area in the document image based on the target predefined edge, wherein determining one of the candidate predefined edges to be the target predefined edge includes: sorting the candidate predefined edges to obtain sorted candidate predefined edges; setting one of the sorted candidate predefined edges as a trial predefined edge; performing an attempted identification of a target information area in the document image using the trial predefined edge and a relative positional relation between the target predefined edge and the target information area; if the attempted identification using the trial predefined edge is successful: determining the trial predefined edge to be the target predefined edge; and if the attempted identification using the trial predefined edge is not successful: setting a next one of the sorted candidate predefined edge as a new trial predefined edge; and repeating the attempted identification of the target information area using the new trial predefined edge and the relative positional relation.