openseadragon/www/developer-debug-mode.html

<h2>developer: debug mode</h2>

<div class="description">
  Enabling developer mode provides some in-context information
  about the tiles being drawn in a given viewport. <br/><br/>
  Currently this is only implemented for browsers supporting 
  HTML Canvas.
</div>

<div class="demoarea">
    <div class="demoheading">
        Seadragon in debug mode.
        <span id='consolelog'></span>
    </div>
    <div id="contentDiv" class="openseadragon"></div>
</div>

<script type="text/javascript">
    // Example
    OpenSeadragon({
        id:              "contentDiv",
        prefixUrl:       "/openseadragon/images/",
        tileSources:     "/openseadragon/examples/images/highsmith/highsmith.js",
        showNavigator:   false, 
        debugMode:       true,
        //debugGridColor:  "#f9276f",
        //minZoomImageRatio: 0,
        //maxZoomPixelRatio: 10000
    });
</script>

<p>
The relevant configuration options are shown below.
</p>

<pre>
    OpenSeadragon({
        ...
        debugMode:  true,
        ...
    });
</pre>