feat: set a threshold value when activating an overlay
feat: set a threshold value when activating an overlay

crs4/ome_seadragon,crs4/ome_seadragon,lucalianas/ome_seadragon,crs4/ome_seadragon,lucalianas/ome_seadragon,lucalianas/ome_seadragon,crs4/ome_seadragon,lucalianas/ome_seadragon