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The discovery of multiply-imaged gravitationally lensed QSOs is fundamentalto many astronomical and cosmological studies. However, these objects are rareand challenging to discover due to requirements of high-angular resolutionastrometric, multiwavelength photometric and spectroscopic data. This haslimited the number of known systems to a few hundred objects. We aim to reducethe constraints on angular resolution and discover multiply-imaged QSOcandidates by using new candidate selection principles based on unresolvedphotometric time-series and ground-based images from public surveys. Weselected candidates for multiply-imaged QSOs based on low levels of entropycomputed from Catalina unresolved photometric time-series or Euclideansimilarity to known lenses in a space defined by the wavelet power spectra ofPan-STARSS DR2 or DECaLS DR7 images, combined with multiple {\it Gaia} DR2sources or large astrometric errors and supervised and unsupervised learningmethods. We then confirmed spectroscopically some candidates with the PalomarHale, Keck-I, and ESO/NTT telescopes. Here we report the discovery andconfirmation of seven doubly-imaged QSOs and one likely double quasar. Thisdemonstrates the potential of combining space-astrometry, even if unresolved,with low spatial-resolution photometric time-series and/or low-spatialresolution multi-band imaging to discover multiply-imaged lensed QSOs.

Gaia GraL: Gaia DR2 Gravitational Lens Systems. V. Doubly-imaged QSOs discovered from entropy and wavelets