Inspection group of cylinder-shaped elongated elements for smoking articles, in which the inspection group comprises: - a projecting device adapted to project: a first stripe of light from a first half space onto an inspection portion of an external face of a first elongated element to obtain a first three-dimensional light trace on said external face; a second stripe of light from a second half-space on said inspection portion to obtain a second three-dimensional light trace on said external face; and in which the first half space and the second half space are arranged on opposite parts with respect to a working plane passing through a longitudinal axis (S') of the first elongated element; - an optical assembly adapted to process: a first view of the first elongated element framed by the first half space to identify a first curved line; a second view of the first elongated element framed by the second half space to identify a second curved line; - a processing device adapted to reconstruct a first closed curved section profile of the first elongated element, processing the first identified curved line and the second identified curved line, and compare the reconstructed first closed curved section profile with the ideal section profile; wherein the projecting device comprises: - a first projector adapted to project the first stripe of light from the first half space; - a second projector adapted to project the second stripe of light from the second half space; - a first optical apparatus adapted to acquire a first image of the first view; - a second optical apparatus adapted to acquire a second image of the second view; characterized in that the inspection group is adapted to inspect simultaneously the first elongated element and an ideal elongated element, the first elongated element and the ideal elongated element being arranged alongside one another respectively in a first position and in a reference position in such a manner that a longitudinal axis (S') of the first elongated element and a longitudinal axis (S′′′) of the ideal elongated element are both arranged in the working plane; the projecting device being adapted to additionally project the first stripe of light from the first half space onto an external face of the ideal elongated element to obtain a first three-dimensional light trace and the second stripe of light from the second half space onto said external face to obtain a second three-dimensional light trace; the optical assembly being adapted to frame simultaneously from the first half space the first elongated element and the ideal elongated element for processing the first view and additionally identifying a first curved line of the ideal elongated element; and to frame simultaneously from the second half space the first elongated element and the ideal elongated element to process the second view and additionally identifying a second curved line of the ideal elongated element; and in which the processing device is adapted to additionally reconstruct by means of the identified first curved line and the second identified curved line a closed curved section profile of the ideal elongated element and monitoring the reconstructed closed profile of the ideal elongated element, generating a warning if the reconstructed curved profile of the ideal elongated element is different from the ideal section profile. - a projecting device adapted to project: a first stripe of light from a first half space onto an inspection portion of an external face of a first elongated element to obtain a first three-dimensional light trace on said external face; a second stripe of light from a second half-space on said inspection portion to obtain a second three-dimensional light trace on said external face; and in which the first half space and the second half space are arranged on opposite parts with respect to a working plane passing through a longitudinal axis (S') of the first elongated element; - an optical assembly adapted to process: a first view of the first elongated element framed by the first half space to identify a first curved line; a second view of the first elongated element framed by the second half space to identify a second curved line; - a processing device adapted to reconstruct a first closed curved section profile of the first elongated element, processing the first identified curved line and the second identified curved line, and compare the reconstructed first closed curved section profile with the ideal section profile; wherein the projecting device comprises: - a first projector adapted to project the first stripe of light from the first half space; - a second projector adapted to project the second stripe of light from the second half space; - a first optical apparatus adapted to acquire a first image of the first view; - a second optical apparatus adapted to acquire a second image of the second view; - a first projector adapted to project the first stripe of light from the first half space; - a second projector adapted to project the second stripe of light from the second half space; - a first optical apparatus adapted to acquire a first image of the first view; - a second optical apparatus adapted to acquire a second image of the second view;