tents-ibase.png : override CROP=320x320 165x165+142+0
towers-ibase.png : override CROP=300x300 102x102+151+6
twiddle-ibase.png : override CROP=192x192 102x102+69+21
-undead-ibase.png : override CROP=448x512 192x192+32+96
+undead-ibase.png : override CROP=416x480 192x192+16+80
unequal-ibase.png : override CROP=208x208 104x104+104+104
untangle-ibase.png : override CROP=320x320 164x164+3+116
$(IBASE): %-ibase.png: %-base.png