To facilitate the reuse of existing charts, previous research has examined how to obtain a semantic understanding of a chart by deconstructing its visual representation into reusable components, such as encodings. However, existing deconstruction approaches primarily focus on chart styles, handling only basic layouts. In this paper, we investigate how to deconstruct chart layouts, focusing on rectangle-based ones as they cover not only 17 chart types but also advanced layouts (e.g., small multiples, nested layouts). We develop an interactive tool, called Mystique, adopting a mixed-initiative approach to extract the axes and legend, and deconstruct a chart's layout into four semantic components: mark groups, spatial relationships, data encodings, and graphical constraints. Mystique employs a wizard interface that guides chart authors through a series of steps to specify how the deconstructed components map to their own data. On 150 rectangle-based SVG charts, Mystique achieves above 85% accuracy for axis and legend extraction and 96% accuracy for layout deconstruction. In a chart reproduction study, participants could easily reuse existing charts on new datasets. We discuss the current limitations of Mystique and future research directions.

翻译：为促进现有图表的复用，此前研究探讨了如何通过将图表的视觉表示解构为可复用组件（如编码）来获取其语义理解。然而，现有解构方法主要聚焦于图表样式，仅能处理基础布局。本文研究如何解构图表布局，重点关注基于矩形的布局——这类布局不仅涵盖17种图表类型，还包含高级布局（如小多组图、嵌套布局）。我们开发了一款名为Mystique的交互式工具，采用混合主动方法提取坐标轴与图例，并将图表布局解构为四个语义组件：标记组、空间关系、数据编码与图形约束。Mystique通过向导界面引导图表作者逐步指定解构组件如何映射至其自有数据。在150个基于矩形的SVG图表上，Mystique的坐标轴与图例提取准确率超过85%，布局解构准确率达96%。在图表复现研究中，参与者可轻松在新数据集上复用现有图表。我们讨论了Mystique当前局限性与未来研究方向。