Recognition of Online Multistroke Freehand Conic Sections Based on Time-Space Relationship
WANG Shu-Xia1, WANG Guan-Feng2, GAO Man-Tun1, YU Sui-Huai1
1.Department of Industrial Design, School of Mechanical Engineering, Northwestern Polytechnical University, Xian 710072 2.Department of Acoustics and Information Engineering, School of Marine Engineering, Northwestern Polytechnical University, Xian 710072
Abstract A method for interpreting multistroke freehand conic sections is presented based on the time-space relationship. The pretreatment approach based on the time slot is able to interpret the dashed or continuous strokes, and the recognition method is discussed based on space relationship of strokes. The multistroke interpretation of freehand conic sections is divided into the interpretations of the closed and non-closed conic sections. Using the least median squares method fits conic section for the former. The definitions of the rotation angle and the endpoint of generalized stroke of the non-closed conic section are presented, which consists of three stages: the multistroke determination, the sketch generation and the rotation angle and endpoints calculation. A human-computer interface prototype system FSR is developed using the proposed theory, which makes system interface easy and friendly to user. The FSR system is tested with a number of multistroke sketches and the results show that the proposed algorithm achieves a satisfactory interpretative efficiency.
WANG Shu-Xia,WANG Guan-Feng,GAO Man-Tun等. Recognition of Online Multistroke Freehand Conic Sections Based on Time-Space Relationship[J]. , 2011, 24(1): 82-89.
[1] Ye Weiwei, Yu Suihuai, Gou Bingchen, et al. A Method to Get Recognition Data for Multi-Draw Sketch. Application Research of Computers, 2005, 22(12): 157-159 (in Chinese) (叶炜威,余隋怀,苟秉宸,等.一种获取重复绘制草图单元识别 特征数据的方法.计算机应用研究, 2005, 22(12): 157-159) [2] Qin S F. Investigation of Sketch Interpretation Techniques into 2D and 3D Conceptual Design Geometry. Ph.D Dissertation. Cardiff, UK: University of Wales Institute. School of Engineering, 2000 [3] Mitani J, Suzuki H, Kimura F. 3D Sketch: Sketch-Based Model Reconstruction and Rendering. Dordrecht, Netherlands: Kluwer Academic Publishers, 2002 [4] Gross M D, Do E Y. Drawing on the Back of an Envelope: A Framework for Interacting with Application Programs y Freehand Drawing. Computers and Graphics, 2000, 24(6): 835-849 [5] Kara L B, Stahovich T F. An Image-Based Trainable Symbol Recognizer for Handdrawn Sketches. Computers and Graphics, 2005, 29(4): 501-507 [6] Fiore F D, Reeth F V. A Multi-Level Sketching Tool for Pencil-and-Paper Animation // Proc of the AAAI Spring Symposium Series: Sketch Understanding. California, USA, 2002: 32-36 [7] Fonseca M J, Pimentel C, Jorge J A. CALI: An Online Scribble Recognizer for Calligraphic Interfaces // Proc of the AAAI Spring Symposium: Sketch Understanding. California, USA, 2002: 51-58 [8] Sezgin T M, Davis R. Handling Overtraced Strokes in Hand-Drawn Sketches // Proc of the AAAI Spring Symposium Series: Making Pen-Based Interaction Intelligent and Natural. Washington, USA, 2004: 21-24 [9] Sun Zhengxing, Feng Guihuan, Zhou Ruohong. Techniques for Sketch-Based User Interface: Review and Research. Journal of Computer-Aided Design and Computer Graphics, 2005, 17(9): 1889-1899 (in Chinese) (孙正兴,冯桂焕,周若鸿.基于草图的人机交互技术研究进展.计算机辅助设计与图形学学报, 2005, 17(9): 1889-1899) [10] Sun Zhengxing, Jiang Wei, Sun Jianyong. Adaptive Online Multi-stroke Sketch Recognition Based on Hidden Markov Model // Proc of the 4th International Conference on Advance in Machine Learning and Cybernetics. Guangzhou, China, 2005: 948-957 [11] Day C K, Qin S F, David K W. Interpretation of Overtracing Freehand Sketching for Geometric Shapes // Proc of the 14th International Conference in Central Europe on Computer Graphics, Visualization and Computer Vision. Plzen, Czech Republic, 2006, 263-270 [12] Wang Shuxin, Gao Mantun, Qi Lehua. Online Freehand Sketching System Using Fuzzy Theory. Pattern Recognition and Artificial Intelligence, 2008, 21(3): 317-325 (in Chinese) (王淑侠,高满屯,齐乐华.基于模糊理论的在线手绘图识别.模式识别与人工智能, 2008, 21(3): 317-325)
2011, Vol. 24 
