  Recently, RGBD-based category-level 6D object pose estimation has achieved
promising improvement in performance, however, the requirement of depth
information prohibits broader applications. In order to relieve this problem,
this paper proposes a novel approach named Object Level Depth reconstruction
Network (OLD-Net) taking only RGB images as input for category-level 6D object
pose estimation. We propose to directly predict object-level depth from a
monocular RGB image by deforming the category-level shape prior into
object-level depth and the canonical NOCS representation. Two novel modules
named Normalized Global Position Hints (NGPH) and Shape-aware Decoupled Depth
Reconstruction (SDDR) module are introduced to learn high fidelity object-level
depth and delicate shape representations. At last, the 6D object pose is solved
by aligning the predicted canonical representation with the back-projected
object-level depth. Extensive experiments on the challenging CAMERA25 and
REAL275 datasets indicate that our model, though simple, achieves
state-of-the-art performance.
