﻿ Digital Image File Archiving
Dean M. Chriss

Digital Image File Archiving
Your Photographic Legacy in a Shoebox?
August 22, 2013

Male Orangutan, Sabah, Malaysia
Male Orangutan, Sabah, Malaysian Borneo
Image archiving strategies of the past were many and varied, but all depended on putting the image itself somewhere for safe keeping. For instance, treasured family photos have often been found in shoeboxes or bags that were stored in someone’s attic for a very long time. More organized folks kept photo albums, and the diligent ones even kept the corresponding negatives safely tucked away somewhere. Serious photographers with thousands of images kept transparencies and negatives organized in hanging files. That was then.

Now there is no film or paper, and no "image" in the true sense of the word. We generate image files with digital cameras, but these image files are not images. They are invisible bits and bytes that are used to construct the image each time it is viewed. This fact poses significant problems for the long term viability of digital images. The ability to view or print digital image files depends on computer hardware being compatible with the media upon which the files reside. It also depends on viewing software that is compatible with the image file format, the computer, and its operating system. If any of these compatibilities vanish over time, the ability to view or print the digital image file vanishes with it, no matter how safe the digital image file has been kept. In addition to long-term file compatibility issues, archiving strategies need to account for normal events that could jeopardize the files. These include accidental erasure, computer viruses, hard drive or other media failure, and catastrophes like fire and flood. It takes a lot more than a shoe box to pass these files on to future generations, and anyone who shoots with a digital camera will eventually have to figure out how to safely store thousands or tens of thousands of digital image files. Keeping them strewn around on your computer’s hard drive is a disaster waiting to happen. It's only a matter of when, not if, files will be lost.

Currently, the most suitable and common storage media are external or internal hard disk drives. A system using these or any other media for image file archiving should ideally meet the following five criteria:

1. Accessibility. There should be a means to easily find any given image without any cataloging program or image database program. A very good level of accessibility can be achieved by simply creating a logical folder structure in which to store your files. This together with a good image browser will let you find any file in short order. Databases with image rankings, and the like are icing on the cake, but the basic ability to locate images is essential. Attaining a good level of safety for your stored images is only a little more difficult.

2. Safety. The data should be safe in the face of hard drive failures, computer viruses, accidental erasures, and even catastrophes like fire and flood. Hard drive storage is convenient and fast, but it is far from safe. Hard drives are quite vulnerable to mechanical failures. These can occur from impact or deterioration of their very precise internal mechanisms over time. This is especially true if the hard drive is used where temperature and humidity are uncontrolled. Data on hard drives is also subject to destruction by computer viruses and simple user errors. RAID (Redundant Array of Independent Disks) can offer instantaneous backup of data as it changes. That answers the file safety issue in the event of mechanical hard drive failure but RAID systems are ineffective protection against catastrophic events like fire, and they are as vulnerable to computer viruses and human error as any single hard drive. RAID systems are also relatively expensive. Whether or not RAID is used, only a good offsite backup or duplicate disk that is updated regularly can prevent data loss in catastrophic situations. I prefer an exact duplicate disk as opposed to a backup of data that needs special software to create the backup and to restore it. A duplicate is easily created with an appropriate copy command and when needed it can be physically substituted for the original disk  and used immediately. If you work in a Windows environment use the "robocopy" command with the "/mir" swich. It's very fast, avoids copying files that have not changed, gives a true "plug and play" duplicate of the original drive's contents.

3. Convenience. Ideally, the system should be convenient to use on a day to day basis. Hard drives offer excellent convenience because they are fast, can store loads of data, several can be connected to a computer at once, and all of your image files can be online continuously. CDs and DVDs store relatively small amounts of data, they are slow, and usually only one at a time can be accessed by a computer.

4. Ease of converting file formats. Digital RAW files generated by today’s cameras are doomed to obsolescence in the reasonably near future. If they are to be useful in the future they will eventually need to be converted to a standard format, if one is ever agreed upon. At the very least, they will need to be converted to something that is compatible with media, software, and computers of the future. Image files on a hard drive are converted most easily. A program reads files from one folder and outputs the converted files to another. It doesn’t get much easier than that.

5. Ease of transfer to future media. No media type will be around forever. It is a pretty good bet that fifty years from now it will be either difficult or impossible to read today’s hard drives or Compact Disk media. Again, data stored on a hard drive is most easily transferred to other media. It is all online, accessible, and ready to be copied to whatever the new device happens to be.

Long ago when we were still scanning film we used to archive our image files on CD and DVD media, keeping duplicate copies of each CD and DVD at an offsite location in case disaster strikes. We kept doing this when we moved to digital cameras. It worked well enough at first, but the problem of file format and media obsolescence loomed ever larger as we burned more and more DVDs. In fairly short order we made the switch to archiving images on a pair of large hard drives, one of which was stored offsite. Not long after that we added a third hard drive to the mix, which is also kept offsite. The offsite backups are updated alternately so all of the data is never connected to a computer at the same time. This scheme virtually eliminates the chance that all of our files would be lost in any catastrophe. Having the discipline to update the offsite duplicate disks on a frequent and regular basis is the weak link in this system. Using a RAID 1 hard drive pair on the computer better assures the safety of images generated between updates of the offsite backup disks, but a little diligence with local backups can provide a very good level of security without a RAID setup on the computer. Basically, no image is safe unless it exists in at least two, and preferably three, different hard drives.

The only certainty in this digital age is rapid change. If someone finds a box of CDs or an external hard drive in your attic a century from now the media and the files on it will both be useless. It is quite obvious that the digital image files of today will not survive far into the future without periodic maintenance. Who is going to maintain your image files ten, twenty, or fifty years after you are gone? It is sad but true that most digital images from today will be lost to the obsolescence of their file formats and/or media type. In light of this it seems odd that our great grandparents could pass wonderful black and white images down through generations with nothing more sophisticated than a shoe box. Perhaps some digital genius can learn from this and come up with an electronic equivalent of that shoebox. Without that, the best way to ensure the long term survival of an image is to print it using high quality archival materials. It can then be put into a shoebox (preferably one that is acid-free) where it will likely survive for a couple centuries with no maintenance at all. Such a print will far outlast the digital file from which it was created, unless those digital files have a diligent caretaker.

Happy archiving.