An original method is proposed to extract the most significant volumetric structures in an illuminance image. The method proceeds in three levels of organization managed by generic grouping principles: (i) from the illuminance image to a more compact representation of its contents by generic structural information extraction leading to a basic contour primitive map; (ii) grouping of the basic primitives in order to form intermediate primitives, the contour junctions; (iii) grouping of these junctions in order to build the high-level contour primitives, the generic volumetric structures. Experimental results for various images of cluttered scenes show an ability to properly extract the structures of volumetric objects or parts with planar and curved surfaces. Keywords Illuminance Image