1. A computer-implemented method for repairing an electronic version of a damaged document, comprising: receiving a scanned halftone image of the damaged document; determining one or more halftone structure parameters; estimating contone gray levels for portions of the damaged document; identifying locations of halftone cell tiles in the damaged document and the positions of pixels within the identified tiles; building a halftone profile model that describes halftone dot growth patterns using the determined halftone parameters and estimated contone gray levels; filling in a damaged region of the document using the halftone profile model and estimated contone gray levels to generate a restored digital halftone image; and outputting the restored digital halftone image.