Research on online sketch understanding technology
In recent years, hand-drawn sketches have begun to appear on the Internet. Understanding online hand-drawn sketches will provide a guarantee for efficient use and efficient editing of hand-drawn sketches.
The object of online sketch understanding is the online sketch drawn by the user with a digital pen, while the object of offline sketch understanding is the image.
The main content I reproduce is "sketch structure understanding".该论文采用动态规划方法提取概念图中的节点和连线笔划块，通过图划分的方法降低图的动态规划的时间复杂度，在此基础上提取由节点、连线和节点连线关系组成的概念图结构。
The goal of the structure understanding method of hand-drawn concept maps is to extract the nodes, connections, and relationships between them in the concept map. The input of the hand-drawn concept map structure understanding method is a sequence of strokes, that is, Input={s1,s2,…,sn}. Among them, n is the number of strokes, si is the i-th stroke, which consists of two-dimensional coordinate points.
The main idea is to segment the hand-drawn concept map by identifying connecting strokes, and use dynamic programming method to merge the cut stroke blocks, and extract the node stroke blocks and connecting stroke blocks in the hand-drawn concept map. Finally, the structure of the concept map is extracted on this basis.
1. Stroke input
I modified the open source project of extracting the stroke order trajectory of handwritten Chinese characters to simulate handwriting through the mouse, and obtained a series of (x, y), each stroke ending in (-1,-1).
2. Preprocessing
3. Sub-problem division based on graph division
4. Stroke block extraction based on dynamic programming
5. Concept map structure extraction