DIZI: A Digital Ink Zooming Interface for Document Annotation

Pen computing devices provide a natural interface for annotating documents with freeform digital ink. However, digital ink annotations are usually larger and sloppier than real ink annotations on paper. We present DIZI, a focus+context interface that zooms up a region of the underlying document for inking. Users write in the zoomed region at a comfortable size for the device. When the zoom region is shrunk back to normal page size, the digital ink shrinks to an appropriate size for the underlying document. The zoom region covers only a small portion of the screen so that users can always see the overall context of the underlying document. We describe several techniques for fluidly moving the zoom region to navigate the document. We show that DIZI allows users to create digital ink annotations that more closely mimic the look of real ink annotations on physical paper.