A knuckle boom crane, for offshore application, which knuckle boom crane comprises: - a crane house, - a knuckle boom, carried by said crane house, - operating means for operating said crane house and said knuckle boom, and - control means, for piloting said operating means, said knuckle boom comprising a main boom and a jib, in series, said main boom and said jib each including an upstream end (312, 322) and a downstream end (313, 323), said crane house comprising knuckle means for defining a slewing motion of the knuckle boom about a slewing axis, said crane house and said upstream end of the main boom cooperate through upstream knuckle means to define a luffing motion of said main boom about an upstream knuckle axis, said downstream end of the main boom and said upstream end of the jib cooperate through downstream knuckle means to define a folding motion of said jib about a downstream knuckle axis, said operating means including: - at least one slewing actuator, for generating the slewing motion of said knuckle boom, - at least one first linear actuator, for generating said luffing motion of said main boom, and - at least one second linear actuator, for generating said folding motion of said jib, and said control means include an active compensation module that is designed to pilot said operating means, taking into account data coming from a motion reference unit, in such a way as to stabilize the downstream end of the jib, advantageously in a horizontal plane and/or a vertical position, still preferably in all directions, wherein said at least one second linear actuator is connected to said crane house and to said jib, wherein said at least one second linear actuator is connected to said jib through mechanical transmission means, characterized in that the mechanical transmission means comprise a deformable parallelogram structure that comprises: - at least one longitudinal arm, interposed between said at least one second linear actuator and said jib, advantageously extending opposite and along the main boom, and - at least two swing arms, each interposed between said longitudinal arm and the main boom. The knuckle boom crane, according to claim 1, characterized in that said at least one second linear actuator has two ends: - an upstream end assembled directly with the crane house, and - a downstream end assembled with the jib through the mechanical transmission means. - a crane house, - a knuckle boom, carried by said crane house, - operating means for operating said crane house and said knuckle boom, and - control means, for piloting said operating means, said knuckle boom comprising a main boom and a jib, in series, said main boom and said jib each including an upstream end (312, 322) and a downstream end (313, 323), said crane house comprising knuckle means for defining a slewing motion of the knuckle boom about a slewing axis, said crane house and said upstream end of the main boom cooperate through upstream knuckle means to define a luffing motion of said main boom about an upstream knuckle axis, said downstream end of the main boom and said upstream end of the jib cooperate through downstream knuckle means to define a folding motion of said jib about a downstream knuckle axis, said operating means including: - at least one slewing actuator, for generating the slewing motion of said knuckle boom, - at least one first linear actuator, for generating said luffing motion of said main boom, and - at least one second linear actuator, for generating said folding motion of said jib, - at least one slewing actuator, for generating the slewing motion of said knuckle boom, - at least one first linear actuator, for generating said luffing motion of said main boom, and - at least one second linear actuator, for generating said folding motion of said jib, and said control means include an active compensation module that is designed to pilot said operating means, taking into account data coming from a motion reference unit, in such a way as to stabilize the downstream end of the jib, advantageously in a horizontal plane and/or a vertical position, still preferably in all directions, wherein said at least one second linear actuator is connected to said crane house and to said jib, wherein said at least one second linear actuator is connected to said jib through mechanical transmission means, characterized in that the mechanical transmission means comprise a deformable parallelogram structure that comprises: - at least one longitudinal arm, interposed between said at least one second linear actuator and said jib, advantageously extending opposite and along the main boom, and - at least two swing arms, each interposed between said longitudinal arm and the main boom. - at least one longitudinal arm, interposed between said at least one second linear actuator and said jib, advantageously extending opposite and along the main boom, and - at least two swing arms, each interposed between said longitudinal arm and the main boom. The knuckle boom crane, according to claim 1, characterized in that said at least one second linear actuator has two ends: - an upstream end assembled directly with the crane house, and - a downstream end assembled with the jib through the mechanical transmission means. - an upstream end assembled directly with the crane house, and - a downstream end assembled with the jib through the mechanical transmission means.