Mask              936 butteraugli.cc   Mask(mask_xyb0, mask_xyb1, mask, mask_dc);
Mask             1713 butteraugli.cc   Mask(rgb_planes, rgb_planes, &scale_xyb, &scale_xyb_dc);
Mask              439 butteraugli.h    void Mask(std::vector<ImageF>* BUTTERAUGLI_RESTRICT mask,
Mask              474 butteraugli.h  void Mask(const std::vector<ImageF>& xyb0,