raster layer to shapefile

?Dear list members,

How to export a raster layer to a shapefile (or other format) to open this
last one in QGIS.
Best,

shapefiles are vector data (points, lines, polygons) so you
definitely need another format. My current favourite raster format is
GeoTIFF, which the raster package and the rgdal package can probably
handle.

Barry