A computer-implemented method includes receiving a set of representative machine image regions for a computing environment wherein the set of representative machine image regions collectively comprise a set of representative image chunks. The method also includes generating a fingerprint for each representative image chunk within the set of representative image chunks to produce a set of representative fingerprints, generating a fingerprint for selected image chunks within a measured machine image region to produce a set of sampled fingerprints, and determining a deduplication metric for the measured machine image region based on the representative fingerprints and the sampled fingerprints. A corresponding computer program product and computer system are also disclosed herein.