Photos from an old CD come out grey or broken

Many of us backed up our photos on CDs and DVDs in the 2000s. Those discs are now 15 to 25 years old, and a lot of them are slowly failing. The photos may not copy at all, or they open grey from halfway down, or shifted sideways and in the wrong colours. Here is why, how to get the most off the disc, and what can be repaired.

Why old discs fail

A burned disc keeps its data in a very thin layer. Over the years light, heat and damp make that layer fade or corrode, often starting at the outer edge. This is called disc rot. The drive can still read most of the disc, but not some spots.

A disc stores everything in small pieces of 2 KB each, called sectors. A photo of a few megabytes is spread over hundreds of them. One unreadable sector is enough to break the photo.

First: copy off what can still be read

Copying with Explorer or Finder usually stops at the first error, or leaves the photo out. Use a copy program that skips the unreadable spots and keeps going instead:

• IsoBuster or Unstoppable Copier on Windows, ddrescue on Linux and Mac. They keep everything they can read, and put zeros where a sector can't be read. That is the kind of damage memories.repair is made for.
• Try another drive if a disc gives many errors: drives differ, and one can often read sectors another can't. Wipe the disc gently with a soft cloth, in straight lines from the centre outwards.
• Copy each disc once to your computer and work on the copies. Every extra read is a risk for a failing disc.
• Keep every copy of the same photos: a second disc, an old backup, the photos you once emailed. A sector that is lost on one copy is very often fine on the other.

What you see

A photo with a lost sector is fine down to the lost spot. After it, the photo viewer either shows grey to the bottom, or the rest of the picture shifted sideways and in strange colours. The picture data after the gap is still in the file, it just no longer knows where it belongs (why that happens).

What can be repaired

memories.repair finds every lost spot in the photo and puts the pieces after it back in their place. To find the right place it uses the small preview the camera stored inside the photo. It then fixes the colours and fills in the strip that was really lost. A lost sector is only a thin strip of the picture, so the filled part is small; it looks a bit blurry close up. Everything else is your original photo.

• Two damaged copies of the same photo? Upload one, then use "Add another copy" in the viewer: what one copy lost is taken from the other, and the filled-in strips get real picture back.
• A photo that doesn't open at all has lost its very beginning. It can often still be repaired with the help of an intact photo taken with the same camera, for example another photo from the same disc.
• Don't open the broken photos in an editor and save them again. Saving keeps only what the viewer shows and throws away the part the repair needs.

Seeing what can be saved is free: you get the diagnosis and a preview of the repair before you pay anything.