Something is corrupting my jpegs. How can I trace what did this?

Question

I keep finding jpeg images on my laptop, which are corrupt. Some have a gray band at the bottom, some are reported bad by Bad Peggy (but look normal when viewed in e.g. XNView) and some are just unreadable by XNView or any other program. Is there any way to determine, which program last modified the image? Thanks in advance, Steve

Answer 1

In general, you cannot determine which application last changed a file (whatever the file, image, spreadsheet...).

You can have a clue that the file has been changed by an application because usually this changes the modification date of the file (as displayed in your file explorer). The only applications that don't change files time stamps are those that copy them (move them to another drive, restore them from backups, etc...). So you can check the file time stamps in your explorer to see if they are coherent with the time the picture where taken or at least imported on your laptop, and if as a coincidence your corrupted files are more recent than the rest.

If you know that the files were good as some point in time, then either

• The file system is corrupted (ie, Windows mixed up which parts of the disks belong to which file). There may be utilities that check this (but if they can confirm the problem, I doubt that they can repair the files).
• Your disk is failing (which is the more likely case). This can be confirmed by using a utility that will check the SMART data of the drive. As above, that doesn't recover the files... And if the utility says that your drive doesn't support SMART, then it's so old that it is probably worn out.

Answer 2

If the corruption seems to be random or random-ish, spontaneous, degrading a little more every day... I had that problem years ago with one computer. Some files just went bad. Others, only after the file manager attempted to make thumbnails or display the file in a viewer. Turned out to be a loose cable between the motherboard and disk. Back then it was a ribbon cable, on tight enough to work most of the time but just barely loose enough to cause some data bits, one out of every few million, to glitch occasionally. Some of the executables got corrupted, appearing to run fine but quietly corrupting data files such as images. Once I found the cable, I pushed it on tight, re-loaded everything from backups, and the problem never happened again.

So check your hardware internals. Other signal integrity issues could be a microcrack in a circuit board, bad memory chip bits, or some rare CPU chip bug that escaped testing.