“…To address both problems, instead of storing whole images from the previous tasks {1, ..., t − 1}, we propose to store an informative portion that we will mix with the images of the current task t. Image mixing is popular for classification [93], [94], [95], [96], [97], [98] yet, to the best of our knowledge, sees limited use for semantic segmentation [99], [100], [101], [102], [103], and has never been considered to design memory-efficient rehearsal learning systems. Formally, given an image I and the corresponding ground truth segmentation maps S t , we define a binary mask Π c such that ∀c ∈ C t : with O c the selected object for class c. By nature, this patch is extremely sparse and can be efficiently stored on disk by modern compression algorithms [104].…”