support reading OpenSlide associated images
support reading OpenSlide associated images

leiyangyou/libvips,jcupitt/libvips,wishabi/libvips,wishabi/libvips,mcanthony/libvips,mcanthony/libvips,mcanthony/libvips,jcupitt/libvips,jcupitt/libvips,lovell/libvips,leiyangyou/libvips,wishabi/libvips,lovell/libvips,leiyangyou/libvips,mcanthony/libvips,lovell/libvips,lovell/libvips,leiyangyou/libvips,wishabi/libvips,jcupitt/libvips