Missing or unrepresentative Thumbnails and Previews

Background

The images that IMS shows you through your browser are derivative versions of the original created for preview purposes. When you upload the original, IMS will generate a number of derivatives in various sizes (e.g. 'thumbnails' for search results, 'previews' for display in the file console). In some situations IMS will not be able to display these and instead displays a generic graphic to represent the file (such as the example above). This page lists the possible reasons why it may not be possible to display something more representative.

1) A valid preview exists but your browser is displaying an older cached version of the file from a time when it may have had a problem

Force-reload the page in your browser to be sure that your browser is showing the most recent graphics from the server. It may help to use this after a 'Replace File' operation for example.

2) The IMS server was previously unable to generate a preview but software updates or previous storage or memory limitation problems (that are now resolved) may mean that a new attempt could be successful.

On the File Console page underneath the preview is a tab marked Other Actions. If a button marked Re-create thumbnails exists, use that trigger regeneration of the preview. Remember to reload your browser's cache after using this (as explained in 1).

If the Re-create thumbnails button is not present, please us the Replace File button instead and re-upload. Thumbnails and previews are only created at upload time hence then need to re-upload.

3) You have uploaded a file IMS can't fully interpret and so the preview doesn't look right

Some file formats are proprietary which means that the creators do not document the internal format making it difficult for third parties to read them. File formats produced by Adobe and Microsoft are often proprietary.

Despite the lack of documentation, software libraries do exist to help third parties (such as Third Light) to read such files. Third Light include these libraries in their IMS software although they are not created by Third Light themselves. These libraries may not be perfect and sometimes result in graphical glitches that don't accurately portray the contents of the original. In such case Third Light need to wait for a new version of these graphics libraries to be produced by external organisations and then test them to see if the updated version offers an improvement. If they do, the new release of the IMS software will contain the updated graphics libraries.

If you are experiencing problems with thumbnails and are not on the latest version of IMS, consider updating as later version of the software may be more successful. You can then try regenerating the previews as described in case 2) or re-uploading via 'Replace File' as described in case 1).

4) The file type is not on our supported list

Please see our list of supported File and Video Types. If you have files that are not in this list, you could try uploading them but if you see a 'binary icon' i.e. a graphic showing 1s and 0s, that would suggest that the format is not supported.

5) IMS needs more time to create the preview

Creating thumbnails and preview can be an intensive task that takes a lot of CPU, RAM and disk. The faster the hardware, the sooner the preview will be created. Preview creation tasks are put onto a processing queue. A preview may not be created immediately if there are other tasks ahead of it on this queue. This can include tasks being performed by other users who are using the system at the same time as you.

Uploading large amounts of video can take a very long time. Do not be surprised if it takes several days. Files that appear to be stuck at 0% are still waiting for their turn to be processed.

You can reduce the time and space needed to create previews by altering the size of the preview created or by changing bitrate settings for video. Please see a separate FAQ.

6) The size of a file is larger than the allowed limits

To prevent very large files from consuming excessive amounts of system resource such as memory, previews will not be generated above certain thresholds:

This information is also listed on the Configuration > Site Options > Thumbnail Settings page.

The limits are designed to avoid exhausting system resources on intensive preview generation tasks.
Please consider upgrading to a system with more CPU cores and RAM if you consistently need to store and preview files larger than these limits.

7) The dimensions of a file are larger than the allowed limits

To prevent very large files from consuming excessive amounts of system resource such as memory, previews will not be generated above certain thresholds.

The general rule for the maximum number of megapixels permitted is system memory in kilobytes divided by 36000.

The Maximum Pixel Dimensions allowed for your IMS system can be seen on the  Configuration > Site Options > Thumbnail Settings from IMS version 6.1.14 onwards. Please note that the dimension limits are in width-by-height order and are not reversible.

8) Storage space has run out

Check that you have not exhausted diskspace from the Reporting > Storage page

9) Your IMS server connects to storage on another computer but that is no longer available (Enterprise Edition only).

If your storage is mounted over NFS, network disruption or a power outage on the storage server may cause the mount point to be lost making content and thumbnails inaccessible. It maybe necessary to remount the remote data store

e.g.
umount /space2
mount /space2

Alternatively consider safely rebooting i.e. from Configuration > System Administration > Reboot

10) A corrupt image has been uploaded to IMS

Can you download the image to your desktop and view it there? If you can't that would suggest that the source image is corrupt. A filesize in IMS smaller than the one of the original file may indicate network interruption during upload.

11) An extremely memory-intensive file may fail identification attempts

When a file is uploaded, IMS will attempt to categorise it by trying to establish file type, dimensions etc. It is possible that this categorisation may fail if it isn't possible to open this file due to lack of memory. If image dimensions are not displayed on the file console for what you know to be an image file, that would be an indicator of a failed attempt to identify the properties of the file.