Abstract

In this paper, we study the problem of how to segment a freehand sketch at the ob ject level. By carefully considering the basic principles of human perceptual organization, a real-time solution is pre- sented to automatically segment a user’s sketch during his/her drawing. First, a graph-based sketch segmentation algorithm is proposed to seg- ment a cluttered sketch into multiple parts based on the factor of prox- imity. Then, to improve the ability of detecting semantically meaningful ob jects, a semantic-based approach is introduced to simulate the past experience in the perceptual system by leveraging a web-scale clipart database. Finally, other important factors learnt from past experience, such as similarity, symmetry, direction, and closure, are also taken into account to make the approach more robust and practical. The proposed sketch segmentation framework has ability to handle complex sketches with overlapped ob jects. Extensive experimental results show the effec- tiveness of the proposed framework and algorithms.