The Digital Life, Houston We Have a Problem, 106 25/10/08

Picture Imperfect

Can you clarify a theory I have heard that JPEG files deteriorate over time? I have many old family negatives going back to the 1890s on glass plate and everything in between. I am concerned that two generations hence my grandchildren may regret that I kept my photos in JPEG format. What causes the deterioration and can it be avoided?

Andrew Williams, by email

JPEG (Joint Photographic Experts Group) is a data compression scheme and basically a way of reducing the amount of data in a file by discarding redundant information. In practice a JPEG file is no different to any other type of data file; it’s a fixed entity and should not change over time. However, data files can become corrupted or degraded if the storage medium fails and this is something to bear in mind when saving digital data – whatever it represents -- for posterity.

But even if there were such a thing as a storage system that guaranteed data integrity for 50 years or more, how could you be sure the hardware and software necessary to retrieve the data will still be available in 10 years, let alone 50? Just ask anyone with important data held on 5.25 or 3.5-inch floppies, Zip, Travan or QIC cartridges; the list goes on, and will eventually include CD, DVD and Blue Ray.

The only way to ensure digital data will be preserved is to periodically copy it to the prevalent storage format of the day, and this is where tales of JPEGs deteriorating may have originated. If, for example, a JPEG file is opened in an image editing program and then re-saved the file will probably be compressed again, and this results in a drop in quality each time the file is copied. The solution is to delve into the program’s configuration menu and make sure compression is switched off, or copy the file without opening it.  

Take Command of Lists

Is there any way one can print a list of directories and/or their contents?  When backing up or removing photos, for instance, it would sometimes be helpful to keep a list of files along with the backup media.

Jill Collingbourne

Several third-party programs can do this, including free utilities like ExPrint, Karen’s Directory Printer and RJH Extensions etc., (see the Desktop Utilities in the Software section of PCTopTips) but let’s be bold and try a simple little ‘command line’ procedure that works in all recent versions of Windows. Begin by jotting down the path and name of the folder whose contents you want to list and print. For example, the photos I took on a holiday in France last year are in a sub-folder called ‘france07’ and this is in a folder called  ‘pix’ on the C: drive, so the path and folder name in this case is: C:\pix\france07.

Go to Run (or Search in Vista) on the Start menu and type ‘cmd’ (without the quotes), and press Enter. This opens a black Command window with a flashing prompt. Type in ‘cd’ (the Change Directory command), followed by the pathname and press Enter; in my example this would be:

cd C:\pix\france07

Make sure there’s a space between cd and C:\. The display should now show: C:\pix\france07>. At the flashing prompt type the following, and press Enter:

dir /b > c:\listfolder.txt

Note that there are spaces either side of the ‘>’ symbol. This creates a file called listfolder.txt on your C: drive, listing the contents of your chosen folder, which you can open and print in Notepad or your chosen text editor or word processor. In case you are interested ‘dir’ is the directory list command, /b is a ‘switch’ that tells it to leave out the file’s time, date and size information and the > symbol tells it to send the list to the folder called 'listfolder, which it has just created.

Get rid of the Glass

I have a PC running Windows Vista and when I switch it on a ‘Magnifier’ window appears in the right-hand corner of the screen. I know this is useful for some people but I do not need it so can you tell me how to disable it, so that it will not show up on start up?

Kanda Madhavan, Flintshire

I know what you mean, it’s easy to switch it on accidentally, but there’s no obvious way to turn it off again afterwards. To do that you have to go to the Start menu, select All Programs then Accessories, select Ease of Access then click on Ease of Access Centre. This will probably start the ‘Narrator’ program chattering, but you can ignore that. Scroll down the page and click on ‘Make the computer easier to use’ then uncheck ‘Turn on Magnifier’, click OK and hopefully it will bother you no more.

Unwelcome Help

An annoying error message appears when I start my Vista PC. It says: ‘RUNDLL Error loading C\PROGRA~\MYWEBS~\1.bin\MWSBAR.DLL’.  I have to click OK before I can continue. Any advice?

Phil Slade, by email

It’s a BHO or ‘Browser Helper Object, an add-on installed in Internet Explorer by various freebie programs or website pop-ups. To get rid of it open IE then go to Tools > Manage Add-Ons > Enable or Disable Add-Ons. You should find something called ‘MyWebSearch’ on the list (or mwsbar.dll), in which case click on it and select Disable in the Settings box. Exit IE and restart Windows for the change to take effect.

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© R. Maybury 2008 0610