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Table 2

Summary of the criteria we adopted to choose the images included in the different selections of lenses and nonlenses for our experiments.

Selection Lenses nonlenses Total


Criterion Number of images Criterion Number of images
S1 n_pix_source >430 1001 Randomly selected objects with n_sources = 0 1000 2001

S2 n_pix_source >140 5083 Randomly selected objects with n_sources = 0 5000 10 083

S3 n_pix_source >70 9709 Randomly selected objects with n_sources = 0 10000 19 709

S4 n_pix_source >20 19 591 Randomly selected objects with n_source_im = 0 20 000 39 591

Notes. While the identification of the lenses is solely based on the variation of a threshold value for the parameter n_pix_source, the identification of the nonlenses is primarily based on the possible presence and visibility of a background source.

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