Revised set! In the first set which went online there were some errors. Most notably one subset being included twice. Also some transposed images. Tests on the old set are invalid. Henrik Stewénius and David Nistér The set consists of N groups of 4 images each. All the images are 640x480. If you use the dataset, please refer to: D. Nistér and H. Stewénius. Scalable recognition with a vocabul