OpenSeadragon is an open-source, web-based viewer for high-resolution zoomable images, implemented in pure JavaScript, for desktop and mobile.

It is an excellent technology which allows the user to move rapidly around a low resolution version of a large image (such as a map) and then to zoom in tosee the details in high resolution.

Key Instructions

  • Once you have opened a page containing a OpenSeadragon image you have some simple controls (using a mouse or other pointing device) to display what you want to view.
  • Place the mouse cursor somewhere in the image window.
  • Rotate the mouse scroll wheel to zoom in or zoom out.
  • Alternatively a double left click will zoom in.
  • Press and hold down the left button to drag image to view the required area.

Additional Information

Operating in ‘full page’ (full screen) mode is recommended to maximise the viewing area.

  • Find the the bottom right hand corner of the image window (if necessary scroll down the web page)
  • Roll the mouse over the bottom right hand corner of the image window and four icons will appear as shown below
  • Click on the right hand icon to go into full page mode.

To exit full page mode go back to the icon and click it again.

  • Click the plus [+] icon (or use the mouse scroll wheel) to zoom in.
  • Click the plus [-] icon (or use the mouse scroll wheel) to zoom out.
  • Home
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To learn more about OpenSeadragon click here