Deep Zoom Images MIDZ.HTML Displays Blank Screen (When Manually Launched)
Deep Zoom Images

Information in this article applies to:

  • uScope Navigator V4.0 and Later

Article ID: NDZ1264 — Created: 25 Jul 2019 — Reviewed: 12 Oct 2020


I have copied a deep zoom image (Deepzoom-unfiltered folder) to a shared folder on my network. I'm attempting to open the MIDZ.HTML file with my web browser but the browser window is blank and my scanned slide image does not display. What am I doing wrong?


There are only a few reasons why the MIDZ.HTML file does not open the Deepzoom Viewer when run directly.

Deep Zoom Folder Not Copied Completely...

There are a few things to check to make sure the folder contents were properly copied.

  1. Make sure you copied the entire Deepzoom folder.
  2. Check the Deepzoom folder to make sure there is an MIDZ.HTML file. This file is usually copied to the folder the first time it is viewed in uScope Navigator. If the deep zoom image was not viewed, this file may not be there. You can copy it from the C:\Program Files (x86)\Microscopes International\uScopeNavigator folder.
  3. Check to be sure the DZOutput_Files folder and DZOutput.xml file were copied.

Web Browser CORS Support...

CORS (Cross-Origin Resource Sharing) is a security mechanism that web browsers use to allow access to restricted content from another domain. The Deep Zoom Viewer (MIDZ.HTML) performs AJAX requests to read the XML data for each deep zoom image. Some web browsers (most as of 2019) restrict that operation when the data is located on a local (or network) disk. When restricted, the web browser displays a blank screen for the deep zoom image.

  • On Windows 10 PCs, Microsoft Edge seemed to work correctly with no modifications.
  • On MacOS, Safari seems to work correctly with no modifications.

For all other web browsers, you must explicitly give the browser permission to read the XML and image files for the deep zoom image.

Chrome Browser (Windows)...

You can disable the CORS file restriction only on the command line. For example:

chrome.exe --allow-file-access-from-files

You can also add the --allow-file-access-from-files argument to the Properties - Target command line. However, there are several Chrome plug-ins that should work.

Firefox Browser (Windows)...

  1. On the Address Bar, enter about:config.
  2. Search for security.fileuri.strict_origin_policy and change it to FALSE.
  3. Then, reload the page. It should work.

Opera Browser (Windows)...

The only way we found to disable CORS restrictions were with one of the Opera plug-ins that are available.

Edge Browser v86 (Windows)...

The latest version of Edge (v86...) is based on Chrome. The CORS file restriction can be disabled on the command line. For example:

msedge.exe --allow-file-access-from-files

You can also add the --allow-file-access-from-files argument to the Properties - Target command line just like under Chrome.

CORS restrictions are not a problem for deep zoom images served from a web site if the MIDZ.HTML file, XML files, and image files are all served from the same domain.

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