You can lower the bounds significantly. Images do not require comparison to all others, and the presented approach to detecting and deduplicating images in the paper is easily adapted to be near linear (trading for storage or cleverness).
Put simply, do you expect google image search to compare your image to every other possible image? No, they're going to embed it to a vector (512d in the paper) and only compare to probable matches; in the paper they start by brute forcing pairwise comparison of the vectors for the dataset, and then use clique finding to go faster when checking their generated images.
Put simply, do you expect google image search to compare your image to every other possible image? No, they're going to embed it to a vector (512d in the paper) and only compare to probable matches; in the paper they start by brute forcing pairwise comparison of the vectors for the dataset, and then use clique finding to go faster when checking their generated images.