Fig. 2: Glimpse and batch formation: Scanned whole-slide images are annotated and ROIs are extracted (left panel).

ROIs are tiled into HPFs (2nd panel, black lines). HPFs are randomly sampled without replacement across all ROIs of each patient to form a glimpse (third panel, HPF shading indicates glimpse) second panel from left, colored HPFs indicate their corresponding glimpse. Glimpses are constant size (16) except the last glimpse (purple oval) which takes the remainder. Glimpses from one patient are distributed across batches (fourth panel, gray ovals are glimpses from other patients).