PIX_MASK_RETAIN  1932 src/image.c    	    = (four_corners_best (mask, img->corners, img->width, img->height) == PIX_MASK_RETAIN);
PIX_MASK_RETAIN  6302 src/image.c    		      : (have_mask = true, PIX_MASK_RETAIN)));
PIX_MASK_RETAIN  7211 src/image.c    				  ? PIX_MASK_DRAW : PIX_MASK_RETAIN));
PIX_MASK_RETAIN  8321 src/image.c    		PUT_PIXEL (mask_img, x, y, *p > 0 ? PIX_MASK_DRAW : PIX_MASK_RETAIN);