1. A method of locating block edges in an image, comprising: receiving an image having a number of data blocks; generating a first block map using the image, the block map having binary indicators indicating the locations of block edges in the image in a first direction; forming a first direction block edge histogram by accumulating the binary indicators in the first block map in a direction normal to the first direction, the first direction block edge histogram having peaks corresponding to locations of block edges in the first direction; low-pass filtering the first direction block edge histogram to form a filtered first direction block edge histogram; identifying locations of peaks in the filtered first direction block edge histogram; refining the identified peak locations based on the location of peaks in the first direction block edge histogram; and providing block edge location information for the image in the first direction, the block edge locations being based on the refined peak locations.