The DZI (Deep Zoom Image) format is an XML specification maintained by Microsoft and described here.
OpenSeadragon supports the DZI format via AJAX (XML/JSON), JSONP, and as inline configuration (using the JSON format). The DZI specification does not officially describe a JSON format, but the examples below illustrate how DZI XML is mapped to JSON following some simple conventions.
        The DZI format is implied by a tile source specified as a string
        and which has the .dzi extension.  OpenSeadragon sniffs
        for whether the DZI is formatted as XML or JSON.
    
Below is a sample DZI file formatted as XML.
<?xml version="1.0" encoding="UTF-8"?>
<Image xmlns="http://schemas.microsoft.com/deepzoom/2008"
       Format="jpg" 
       Overlap="2" 
       TileSize="256" >
    <Size Height="9221" 
          Width="7026"/>
</Image>
    And the equivalent sample DZI file formatted as JSON.
{
    "Image": {
        "xmlns":    "http://schemas.microsoft.com/deepzoom/2008",
        "Format":   "jpg", 
        "Overlap":  "2", 
        "TileSize": "256",
        "Size": {
            "Height": "9221",
            "Width":  "7026"
        }
    }
}
    
        Configuration is done via the tileSources option
        (or programmatically).
    
OpenSeadragon({
    ...
    tileSources:   "/example-images/highsmith/highsmith.dzi",
    ...
});
        The DZI JSONP format is implied by a tile source specified as a string
        and which has the .js extension.  The remainder of the
        filename is expected to match the JSONP callback.
    
Below is a sample DZI file formatted as JSONP.
highsmith({
    "Image": {
        "xmlns":    "http://schemas.microsoft.com/deepzoom/2008",
        "Format":   "jpg", 
        "Overlap":  "2", 
        "TileSize": "256",
        "Size": {
            "Height": "9221",
            "Width":  "7026"
        }
    }
});
    
        Configuration is done via the tileSources option
        (or programmatically).
    
OpenSeadragon({
    ...
    tileSources:   "/example-images/highsmith/highsmith.js",
    ...
});
        Inline configuration is convenient as well because it avoids a potentially
        complicated JSON/XML AJAX request.  Just drop the equivalent
        JSON directly into the tileSources option.
    
        Configuration is done via the tileSources option
        (or programmatically).
    
        Note however the non-standard DZI property url which we
        must supply explicitly, since this is normally inferred from the path
        specified for the DZI XML/JSON/JSONP.
    
OpenSeadragon({
    ...
    tileSources:   {
        Image: {
            xmlns:    "http://schemas.microsoft.com/deepzoom/2008",
            Url:      "/example-images/highsmith/highsmith_files/",
            Format:   "jpg", 
            Overlap:  "2", 
            TileSize: "256",
            Size: {
                Height: "9221",
                Width:  "7026"
            }
        }
    }
    ...
});