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An Issue

Image Source

Fitting large images or other visual information presentations into a given window often involves compressing or zooming-out. Zooming-out, or compressing the data to fit within the space of the screen, can result in an image that is too dense to discern detail. This image shows a land usage map of Champaign, Illinois compressed uniformly to fit a given frame. While this image shows the full map and is only slightly compressed, it is already hard to discern all the details.

Zoomed In

To obtain a better view of the details one can zoom-in. For example in this image one region of the land use map of Champaign Illionois is magnified or zoomed-in to reveal details of airport runways which were not visible in the zoomed-out image shown here.

With the options of zooming in or zooming out one can see either the full context or the desired details but not both at once.


One option that provides some context with magnified details is to use an inset as in this image. Creating an inset, by zooming-in or magnifying a sub-region in place, obscures local context. The inset provides detail for the selected region but the space required for magnification causes the adjacent regions to be covered, making it impossible to see how the details, for instance roads, in the inset connect to the roads in the rest of the map.


Full map

This presentation contains two distinct views; one shows the full map of Champaign, Illinois and the other shows a selected magnified region.

Multiple views in separate windows allow global structure to be displayed in one view and the required detail in another. connectivity that locates the detail within its context. This presentation displays a magnified sub-region separately in its own frame. This solution removes the occlusion with the use of insets, however the connections between the two images are not necessarily obvious and must be performed consciously by the user.


The difficulty with supporting detail-in-context readings in a windowing environment has led to several techniques that combine the advantages of zooming-in with those of zooming-out. Essentially these techniques allow a user to magnify chosen sections to reveal the desired detail and compensate for the extra space this magnification requires by various types of compression in the rest of the image.

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Last modified: Dec 6, 2006