A Sketch Correction Method for Symmetric Structures based on Two-Point Perspective

Constructing 3D models using two-dimensional sketch images is helpful for designers to check and improve their works intuitively. For objects with symmetric structures, algorithms have been proposed for 3D reconstruction using a single sketch image. However, such algorithms typically require the sketch to be strictly perspective-correct, which is hard to achieve for hand-drawn sketches. This paper proposes a novel method to automatically correct sketches of symmetric structures based on the two-point perspective. Our method only requires the user to draw a perspective-correct cube on the sketch to determine the perspective of the space. Then, it can automatically extract straight lines and curves from the sketch, determine the symmetric pairs of them, and correct the pairs so that they follow the perspective of the cube. Our experiment results show that the proposed method is valid for correcting hand-drawn sketches of symmetric structures.