Segmentation of Online Freehand Sketching Based on Speed Feature

Guanfeng Wang,Jingjing Kang,Shuxia Wang,Shouxia Wang,Maria Patrizia Pera

doi:10.1155/2021/8881187

Guanfeng Wang, Jingjing Kang + Show 3 more

Open Access

https://doi.org/10.1155/2021/8881187

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Abstract

We present a novel method to extract speed feature points for segmenting hand-drawn strokes into geometric primitives. The method consists of three steps. Firstly, the input strokes are classified into uniform and nonuniform speed strokes, representing a stroke drawn at relatively constant or uneven speeds, respectively. Then, a sharpening filter is used to enhance the peak features of the uniform speed strokes. Finally, a three-threshold technique that uses the average speed of the pen and its upper and lower deviations is used to extract speed feature points of strokes. We integrate the proposed method into our freehand sketch recognition (FSR) system to improve its robustness to support multiprimitive strokes. Through a user study with 8 participants, we demonstrate that the proposed method achieves higher segmentation efficiency in finding speed feature points than the existing method based on a single speed threshold.

Highlights

Freehand sketching is a natural and intuitive tool for designers to communicate and visualize their ideas during the conceptual stage of product design
We propose a novel method to extract speed feature points for segmenting hand-drawn strokes into geometric primitives
We presented a method to extract speed feature points for segmenting digital freehand strokes into primitives

Summary

Introduction

Freehand sketching is a natural and intuitive tool for designers to communicate and visualize their ideas during the conceptual stage of product design. Concept designers use paper and pencil to share, communicate, and record new ideas. The paper becomes clutter with all sorts of changes. With the development of tablet computers and electronic pencils, pen-based interfaces have become more and more popular. In recent years, sketchbased user interfaces have been widely studied to enable users to interact with computers with sketches. Sketch-based interfaces have the potential to combine the benefits of the creative and freed nature of pen-and-paper drawing and the processing power of computers [1]

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